"I am the line segment" "I am the line segment" "I am the line segment" "I AM the line segment" "I AM THE line segment" "I am THE LINE segment" "I am THE LINE SEGMENT" "I AM THE LINE SEGMENT" ... "My God. That was strong."
The brain and the 5 senses are not designed to perceive and experience a 3-dimensional universe filled with matter that is flowing through time. Just the opposite, they are designed to create the illusion, the holographic simulation of such a 'reality'.
@@bradstephan7886 I think you're probably putting a little too much emphasis on "the brain and the five senses". Also, "a 3-dimensional universe filled with matter that is flowing through time" is exactly what our brains are designed to handle. They aren't designed to model large sections of it all at once like some kind of computer simulation, but that's not the issue here. The issue here is that the idea of objective space-time, where space and time are not independent of each-other, but rather just arbitrary axes we draw on maps of space-time based on our orientation in space-time (largely position and velocity), which we are inclined to use because that is the most useful way of modeling the space-time near us. If you were to draw a Minkowski diagram with normal time and distance units (like, say, seconds and meters), which are both of sizes that are easily conceivable by humans, then the part of the graph between the speed-of-light lines to the right and left of the origin would have essentially no width, and it would be similar if the origin were moved to represent the perspective of any other point in the spacetime with such units. Similarly, all of the hyperbolas of equal spacetime-interval would look like straight lines. Thus, approximately speaking, the vertical axis gives spacetime-intervals (negative both ways), where each point can be a cause of any point above it (assuming this is a diagram where time flows up). (The spacial axes also give space-time-intervals, but always within margin-of-error of zero and thus without the causal relationship.) The space of events where none of them can have any causal influence on each other, looks approximately like a line. When we consider that a truly accurate Minkowski diagram would need 3 "spacial" dimensions to go along with the one "time" dimension, then we see that this "line" is actually a three-dimensional space, and if we were to take a very large number of slices with different "time"-coordinates (where every point in one slice had the same time-coordinate, which is technically relative, but would be approximately the same for every normal-velocity, remotely nearby-origined reference from), then every slice would have the potential to affect any remotely-nearby point in certain slices (those "after" it) and would not be able to affect others (those "before" it). This is our ordinary understanding of space and time, it is possible because, for some reason, causality does operate in certain directions of space-time and not others (i.e., special relativity does not show that space and time are interchangeable, at least not when we use our normal, causality-based understanding of time, rather than the "t"-coordinate in the Minkowski space, which is actually just something that mostly lines up to our idea of time, largely due to wrong assumptions we make about the way things "move" through (or "exist" in) space and time). What is actually most weird about this (or at least what is least well understood) has nothing to do with the relationship between space and time, but rather the nature of causality; specifically, "what is the difference between cause and effect, between time viewed as going 'forwards' and time viewed as going 'backwards'". Clearly there is a difference, since we perceive that time only goes in one direction, and certain laws, specifically the law of thermodynamics that says that all things lead twards entropy, care about the direction of time, but it is also possible to logically deduce causes from there effects (this the fundamental basis of our memories of events), just as well as it is possible to logically deduce effects from causes (and in fact it is not entirely possible to do either, because of quantum uncertainty, which can only be turned into deterministic physics if you use the "many worlds" interpretation and accept that the position of your "current" "self" is somewhat random, which might come in the somewhat questionable form of neglecting the validity of these ideas of "now" and "self"). As for our "brain" and "5 senses" being "designed to perceive and experience" things a certain way, I think it's analagous the directions forward, backward, right, left, etc. It's easier to think of positions in the field of view simply as directions relative to the eye, as referenced by which photorecepter cells on the retina are fired; however, in order to understand the spaces we live in when our eyes move, we must have an understanding that space is independent of our viewpoint, which can be achieved by knowing how to transform the various coordinate systems so that we can imagine looking spaces stored in our mind from whatever direction we want in our "minds eye". (Yes, this is an overly vision-based explanation, and there are more senses involved and I probably haven't given a great description of how spacial information is stored in brains, but it's just a demonstration of the idea.) Our intuitive understanding of space and time being different is completely serviceable under all of the normal Earth-like conditions we evolved in, and in which everyone grew up in as children and spends most of their lives in, so there has generally been no incentive to put resources into developing these more abstract relativistic spacetime models in our brains. Thus, it is extremely difficult to train oneself to be as comfortable with these ideas as we are with spacial ideas that have been necessary for the survival of us and our ancestors for hundreds of millions of years.
Stagger Lee It took Einstein 10 years to fully understand General relativity. Be patient my friend, your get there in the end. Start right from the beginning, study special relativity first. It’s not lack of intelligence, it’s just gaps in your knowledge that are the problem.
Thre things. 1 Everyone has this problem with grasping General Relativity concepts. The smartest and brightest do and it's normal. 2 Even if you are able to open your mind and accept for the sake of listening and learning, 'real life' and intuitive activities eventually 'bleed in' and contradict and we have to revisit and 're open' our minds. 3 I strongly suggest that all of those here and elsewhere who 'claim' to understand it and accept it are being honest with us or themselves. I do not believe that even those who define this stuff can easily set aside intuition and real world experience. Baloney. They constantly have to 're convince' themselves of the laws of physics as the truth and put intuition aside.
after the 5th time or so i got it, but the problem is that this is a really big topic and he is really trying to bring it on point, i guess it's no problem that one isn't understanding it in the first attempt :)
you just need to familiarize yourself with a few basic concepts of relativity. its actually a lot simpler than it looks and is so intresting, its insane. Just look up a little about "time dilation"(with speed or gravity) and the double slit experiment.
...how time works (or doesn't work) prove exactly that there is no NEED for God . :) science and God can be put in the same sentence, but science and organized religion cannot.
Space and time are illusions. Nothing travels faster than light. Because of this, information cannot travel faster than light. That means that people in the Andromeda galaxy in their "present" probably see something very different in our (us in the Milky Way's) present. Because of this fact, the only thing that exists are the events we can observe between the illusions of space and time (ie. our planet evolving from one of dinosaurs to human life in the telescopes of an observer in the Andromeda galaxy). Knowing space (even if expanding) and time (relative, but not always agreeable) are illusions, causality is the only thing that is real. Basically even though it feels like our whole life is playing out in "reality" from a 3 dimensional sense, it could in fact just be a "physical object" (our whole lives birth to death, the creation and eventual end of the universe, etc.) in a higher, 4 dimensional space. Imagine the 2 dimensional characters in movies we watch on screen truly believing that their lives and actions in the movie are real and playing out in real time, as opposed to having already being determined for them, in our 3 dimensional world.
GeneticFreak GRD+ I found it easier to understand after I've slept, as with everything I want to understand. I think the mentioned "3 hours" is better spent watching it on as many separate days as you can. Idk why, but something about sleeping...
Watched it a year ago. I understood very little. I understand most of what he says now. I recommend you a book called The Order of Time. It explains it a little bit better.
fabian5002 thank you, I was able to understand most of what he said vs basically none of it a year ago, yet still needed to put a fair amount of conscious effort into the fabrication and holding of these concepts in my mind for the purpose of comprehension and cross-reference. I would love to get to the point where I am able to do this process automatically without having to put any conscious effort into it. Much like holding a metaphorical cup whose shape is foundational knowledge that I no longer notice while holding, so that I may focus explicitly on the contents therein of additional knowledge. This book may be the variable that finally allows me this ability, so I will definitely check it out.
Hello, maybe you could help me to understand one issue. I came here after watching some videos from PBS, and studying philosophy, pondering about issues of time expressed by McTaggart in his article "On the unreality of time", Henri Bergsons conception of subjective time, Humes inquiry about causality, sometimes exploring posibilities to incorporate Leibnizian geometrical monadological aproach. If there is no time, no change and there is just atemporal spatime geometrical fields of events, how it is possible for the guy in video to talk about causality? I can understand how events can be interconected and how can one event point to other if you look on them as constituents of one bigger event. But this seem that one event contains other just contextualy and not substantialy, this is not the hardest issue here. The big thing i dont understand is how can concept of causality work without concept of change because clasical conceptualization of causality works with terms like effect and cause and those indicitates that one event (in the past) authoritatively determines the other in future. But if you have no real change, how can you say that one event is determining other and not oposite way, nor that both determines one another relatively? For what it seems to me people often spoke of determinism as something oposing free will, thinking that past determines future, but to me it seems like such concept of determinism is misunderstanding. Maybe history of universe can be coherent geometrical arangment without change and without past determining future, but with both coexisting and being ordered in a greater coherent structure. But it can be nonsense to think of some part of structure as more free than other. It seems to me that theory of relativity is actually geometrical theory and so can be apriori (concept of pure reason) but this theory does not determine existence of one or other universe, it just provides framework for which universes are possible, which are nonsense, It gives us rules how to build universe but allows many arangements. Now i know that one concept plays a lot with concept of arangment, it is entropy. For some reason entropy is always incresing so it seems like one of those rules for buyilding universes is that it starts with lowest enthropy and it ends with biggest, every universe shares the same big bang as there is only one microstate in big bang but diferentite in the Last moment of biggest entropy because this can have miximum number of microstates. Maybe universe has to be stretch between those to extremes, because at least idea of time, there has to be continuity of similarity, the first and last moments of universe are very diferent but if you give other moments between them in specific arangment, you can create something that seems like continuity of similarity and maybe this continuity of similarity is what theory of relativity can in part describe. Also with regard to entropy, it seems understandable why people think of past as determining future rather than oposite way. Because in any given moment, there is way less more possible pasts than futures and if principle of reversibility is right, than there is just one past. And then when we see whole universe as one single coherent thing yet knowing there was one only possible singularity on one side, big number of possible heat deaths on the other and thanks to the fact that more the two possible heat deaths are simmilar, more simmilar past in form of universe history share, and because what is samé in those histories is always in past but what is diferent is in its future, thats may be how illusion of one way causality is born while in fact there is no causality in this meaning, just causal coherency but no causal determinations. Also in quantuum physics in copenhagen interpretation if you dont measure what happened between two states, you conclude that all possible things happened. It is like saying that there is no real history set between those two states, there exists only those states alone, and by saying what is all possible histories going between them we just say, how simmilar and diferent are those states from one another. But we have many ways how to look on them and how to conceptualize their similarity, therefor we have many possible continusites between them, so if you really want to precise the one exact continuity, you need to include it in another relationship to something other, the more things the relationship is between the more precise it becomes. It can be that substance of space which defines it, are pointa yet only what can really bear some quality is relationship of those points and their diatancies, so by this the qualities are qualities of space. So this was longer than i expected, what i realy want from you guys is to explain me, how the guy in video works with term causality here. Thank you for your answer and for reading this, have a nice day Martin
hello Sheldon i am pretty confused because (causality) by reading your post you seem like a very smart being but then you ask this kind of questions in the youtube comments section! (entropy) @@martinpavlicek2299
@@ivoten LOL i dont understand. It may be useless but why not, sometimes i share such questions on reddit or quora, sometimes with my classmates. It is not so clever, just lots of talk. Have a happy and nice new year
Space and time are illusions. Nothing travels faster than light. Because of this, information cannot travel faster than light. That means that people in the Andromeda galaxy in their "present" probably see something very different in our (us in the Milky Way's) present. Because of this fact, the only thing that exists are the events we can observe between the illusions of space and time (ie. our planet evolving from one of dinosaurs to human life in the telescopes of an observer in the Andromeda galaxy). Knowing space (even if expanding) and time (relative, but not always agreeable) are illusions, causality is the only thing that is real. Basically even though it feels like our whole life is playing out in "reality" from a 3 dimensional sense, it could in fact just be a "physical object" (our whole lives birth to death, the creation and eventual end of the universe, etc.) in a higher, 4 dimensional space. Imagine the 2 dimensional characters in movies we watch on screen truly believing that their lives and actions in the movie are real and playing out in real time, as opposed to having already being determined for them, in our 3 dimensional world.
He is nothing but a scammer who's objective is to use fast talk,mostly lies but a little truth to confuse you.Why? He is using the same techniques taught to salesman,not scientists.
@@jymfysher7704 That's what it appears to you because you lack the background knowledge to understand it. Unlike scams and cults, all the knowledge needed to understand this video is available in math and physics textbooks. Source: I'm an engineer.
@@cosmic_gate476 Ya you got me ! I never could pass math 10 so my math skills are very lame.But I been watching Sobine (The German quantum physicists) and her teaching methods make much more sense to me.Maybe that's becouse school\textbook math should be called a form of calculus or agreed upon system compared to a modular system (No one ever consulted me before teaching me things that just aren't always true !) So I try to understand your textbook math but had many teachers like the guy in this video who seem to go very quickly when explaining things that I find questionable as if there is no need to ponder what he says,just believe becouse he knows so,as you do too !!
He didn't really define spacetime, that "definition" simply pointed it out, identified it as the reality where we can "sense" or experience both space and time between objects and events
Space and time are illusions. Nothing travels faster than light. Because of this, information cannot travel faster than light. That means that people in the Andromeda galaxy in their "present" probably see something very different in our (us in the Milky Way's) present. Because of this fact, the only thing that exists are the events we can observe between the illusions of space and time (ie. our planet evolving from one of dinosaurs to human life in the telescopes of an observer in the Andromeda galaxy). Knowing space (even if expanding) and time (relative, but not always agreeable) are illusions, causality is the only thing that is real. Basically even though it feels like our whole life is playing out in "reality" from a 3 dimensional sense, it could in fact just be a "physical object" (our whole lives birth to death, the creation and eventual end of the universe, etc.) in a higher, 4 dimensional space. Imagine the 2 dimensional characters in movies we watch on screen truly believing that their lives and actions in the movie are real and playing out in real time, as opposed to having already being determined for them, in our 3 dimensional world.
@@SevenFootPelican Thank you so much.... I finally was able to grasp this concept after reading your explanation. This just opened up so many doors for me
I don't know about other, but knowing the concept of spacetime actually give me a lot of comfort. It means everyone you lose you never actually loose them, they are still ”there” in the fabric of spacetime
let me try to help all of you (even myself): the focus on this video it is about reality, OK? The true nature about reality is something that everyone can agrees. If two observers measure somethink and the values of the measurement doesn't match, and still true for both observers separately, it can means two things: thoes observers lives in two paralel's reality, with diferent laws to rule the time and space OR the 'experiense' of reality (events measurement) for both DO NOT correspond to the true and universal nature of reality. And how thoes observers measures reality? counting time and measure space (1D Time and 3D space). If thoes quantities do not match, it means counting time and measure space are NOT the fundamental measurement of reality. Reality is something that both observers can agree. And both agrees about spacetime intervals. That means one thing: probably, spacetime interval is the true measurement of reality, common to both observers without need to invoke two paralel's reality occuring simultaneously. In a nutshell: Time and space are not the reality. time and space are just consequences of this global concept call spacetime, which we perceive as reality in our brains by 3D space and vivid passage of time. The SpaceTime concept is the true nature of reality. Whith this concept understood, the rest of the video is much more clear (to me, at least). I hope I've helped, and sorry about english. Try to explain something that is dificult by itself In a non-maternal language is hard as hell
Good summing up of what this video is trying to get at. Too many commenters watched the video, remember the ending, and forget the important disclaimers, provisos, and guidelines laid down in the first 3 minutes.
humans consider itself intelligence, no one else said it, just us...so are we even consider intelligent creatures by real intelligence that is out there, that is laughing at us? maybe we are not. but since no one came to us and graded us and teach us and tell us where we stand in the universe. we just have to do it ourselves. so whatever we understand and know is the best we got...space is the emptiness all around you and time is a dimension of itself for information to tell where your at in that given space of time. Einstein said time is relative to the observer, so that means time moves in different speed, depending on the awareness of that observer...space and time isn't set to everything to move in the same speed. so reality itself that space and time is a part of, is just the thing you see and can understand.
I think the problem for all of us trying to understand this comes down to grasping the below concepts in combination with each other and finding an example in everyday life in conjunction with space and time to understand it properly forever. 1 Confusion about future, past and present being different for different people 2 Relation with light. 3 Why should we consider space time together always when we have a clear distinction between them on earth and dont need to refer to the other necessarily. I'll try to explain it with a simple example based on my understanding of how everything fits together . There are two people Ana and Rick standing in front of each other in London.Rick sees that Ana is eating an apple at 3:00 pm . She finishes eating it at 3:05 pm. That is Rick's present that he sees that Ana is done eating the apple at 3:05 pm. Now you may think that this is also Ana's present but actually it is NOT. Rick sees Ana because the light is reflected of Ana and enters Rick's eyes. However the speed of light is 300000000 m/s so it is virtually taking almost ZERO time to enter Rick's eyes once its reflected from Ana. So what Rick sees as Ana's present , Ana also agrees with that . However there is a very very very very minute time lapse which is negligible. Now imagine that Ana suddenly gets teleported to New York city and Rick has a big telescope to see Ana. She now eats a banana at 4:00 pm and finishes eating at 4:05 pm . Again , their present and past SEEM TO MATCH because of the very very very negligible time difference leading them to believe that its all happening in the present. Now Suddenly Ana gets teleported to a PLANET X from which it takes light 2 minutes to reach Rick's giant telescope. Now Ana is eating an orange (exactly at 5:00 pm on both earth and PlanetX) and finishes eating it at 5:05 pm . However since light now takes 2 minutes because of the massive distance in space , Rick will not see that Ana has finished eating the orange at 5:05 pm but will see it at 5:07 pm . So at precisely 5:05 pm Ana will say that she has finished eating the orange but Rick will continue to see that Ana is eating the orange . So Rick's present is Ana's past . (Similary for future which i will leave upto you to relate !) So when they were in London standing in front of each other , their present and past differed by approximately 0.000000000000000001 sec and hence couldnt see the differnce and didnt agree it was different When they where in New York City , their present and past differed by approximately 0.000000000001 sec and hence couldnt see differnce again and didnt agree that it was different However with Ana being very far away on a PlanetX, their present and past differed by 2 minutes and boom..they both agreed immediately since now their brain could comprehend that delay in time. This is how the space and time are always bound together no matter where we are. Its just that when light travels so fast, we cannot understand the impact one has on the other for defining past, presence and future. This is the best i can come up with. If I am wrong in my explanation, then do not crucify me !
I like your story about Ana the fruit-eater and Rick the Ana-observer.😂 However, it only explains the delay of events observed over a distance due to the limit of the speed of light, but did not explain the constriction and dilation of space and time, and the differences in the order of events, that are mentioned in the video. In your story, even though Rick sees Ana finishes eating the orange at 5:07 pm, he should also see her starts eating at 5:02 pm, so the duration of the event is still the same for both Ana and Rick, that Ana spends 5 minutes to eat that orange. The weird thing about reality is that different observers can see different distances between two events, different durations between and of the events, and even see the events happening in different orders. Suppose Rick has a big enough telescope to observe Ana eating a cucumber on a planet orbiting a black hole. She starts eating at 6:00 pm and ends at 6:05 pm according to her own clock. Even though she spends 5 minutes in her perspective, Rick will observe the event happening in slow motion and taking a much longer time than 5 minutes, because of the immense gravitational field of the black hole. In contrast, if Rick also spends 5 minutes to eat a cucumber, Ana will see it happening in fast motion and taking much less time than 5 minutes. This is an example of an event having different durations in different observers' perspective.
you explains such events about ana and rick story but even you have no idea or no supplement of instruments which can achieve for you this theory of yours that if Rick also spends 5 minutes to eat a cucumber, Ana will see it happening in fast motion and taking much less time than 5 minutes. This is an example of an event having different durations in different observers' perspective.,i am hoping you all stop that cause its waste of time itself not even anyone can be able to invent time machine to go back in time to see his dead father again neither this reality can change that because when living your father have on memory of some bazaar individual he meet in past who looks like his son then how can we travel back in time to let father have this memory . this means that upcoming many years there is no guarantee of time machine actually invented ,there might be some strange experiments was did by under government support but chances of success are all o % there is no time traveler nor anything successfully being made but research goes on.
I dont think ana can teleport, since rick has The portal gun and can go anywhere faster than ana. Also, you would also see morty freaking out saying, "aww geez rick what the hell are you doing"(like if you get that)
I love how you can come back to a video like this multiple times and each time experience a fresh revelation of understanding, a slightly different more developed perspective
damn I am rewatching this again and I feel your comment! The first time I watched this was four years ago and I can still get a different perspective from it
I came here to say this. Let’s just say the only other times that I actually had the feeling of, “omg is this real” involved acid. I didn’t realize how trippy GR is, now I’m hooked.
hahah I failed physics three times in high school because it never really interested me but I watched a 2min video about spacetime when I was high last night and now I have legit questions about spacetime and physics in general thanks to the internet. So I guess, thank you guys for making me interested in science stuff again
The very best analogy I've ever heard for the concept that all points in time exist simultaneously was from a book called "Illusions" by Richard Bach. One of the characters explained to another that time is like a movie on one of those theater movie reels. The whole movie is there simultaneously for the projectionist. It only appears to flow to the characters in the movie. I read that book over 30 years and that one description has stuck with me all this "time". It's not a science book, btw. It's a short fiction .So don't crack on me if you buy it thinking it was :)
@@i_so_late Why would it work better? They're the same example, except a movie reel has visual motion in addition to the audio. If anything, the movie reel is "better"
I read "Illusions" when I was 17yrs old. Reading that book opened a door in my mind that has led me thru a labyrinth of other doors over a lifetime. Had I not read it, I may have never known those doors even existed. Thank you, Richard Bach
One way I see of understanding it, is if you got back to the past, try to kill Hitler, yet you only become an instrument in his rise to power and shape the history that we already know. Events happen as they always happened, just not in chronological order.
This is the one video that changed (or at least sparked the flame to change) the way I see life and reality forever. I hope I can thank Gabe personally one day
This has to be one of the best expositions of spacetime that I've seen (apart from the still at 5:47 where the text isn't tenseless, "already" implies in the past but it is describing the future).
I think you are saying every single second of my life is being lived at once .inherently I am being born and am dying simultaneously with every other experience I have ever experienced .I just am there is no real end and there was never a real beginning.time is really just a mental invention to make us feel we are keeping track .maybe we just go on forever and ever and those that we know to have died are living their life in another plane from what we perceive to be here and today. I need to take another hit of my joint.see you soon and again and again and again.
[I think you are saying every single second of my life is being lived at once] You yourself are not living all your life at once, at least, you perceive in space and in time. Now, if you could "see" spacetime, and was an observer outside of spacetime, you would in essence be seeing a sort of panoramic of your life. Instead of experiencing the flow of time or the feel of movement, you could look from left to right along that spacetime view and see different parts of your life. If say you had a cosmic filmstrip, say a super 8inty strip (play on super 8 :) ) and it was about 25 milliseconds per frame (cannot remember what the brain frequency of its perception of reality is right now), you could point to any frame and "see" that part of life, but to experience it, you would have to be in that frame and not able to view frames ahead and with some memory of those from before
@@agimasoschandir If you really understand this explain me one thing: The guy in video mentions causality, yet he says there is no separete time and change only spacetime. So if causality is relationship between effect and cause, how can there be any without change in time? I can understand that certain event can relate to other event if they are both part of bigger event and relate to one another in context of that event but than, how can you say which event causes which? Does past causes future or does future causes past or is it relative or both? The question is if you can devide the whole of universe into moments or if you must take it as one indevisible spacetemporal entity. If you cant, than there is no real point to talk about determinism because determinism requires you to determine one part of structure by other part, yet you have no meaningful way how to devide universe. If you devided this unity in your mind like if you dived movie into frames, than you broke those rules mentioned in video. Lets say you break universe into frames of positions of particles. It is clear that to determine the future positions of particles you do not only need to know their positions in presence but also all of their energy and vectors to say where they will move next and how will they interact. But Heisenbergs principle of uncertainity says that object cant have exact position and velocicity measured in once, it is incoherent to describe both to one object. So you have only two options really you can break universe into moments but than you lost information about energy in it or you give up on deviding it and determining exact position of particles, leaving it being spacetemporal objects but than there is no point to talk about determinism.
@@martinpavlicek2299 [If you really understand this ...] Did not specify what I might understand, but in general, I do not. [So if causality is relationship between effect and cause, how can there be any without change in time?] I am unsure why you are proposing there is no change in time. Time is a measurement taken by the observer in their frame. Time and space measurements taken by an observer in a different frame of reference will measure the event differently from another inertial frame (not a frame of a film or video). [Does past causes future or does future causes past or is it relative or both?] We humans have a perception of time happening one way because we have a reference point to measure from what event was the cause and what event was the result, and eventually, a knowledge of related events that tell us the most probable "before" and "after" event. That is not to say other creatures may not, I am using humans in reference to "we". [The question is if you can devide the whole of universe into moments or if you must take it as one indevisible spacetemporal entity] We order our lives by referencing the "now". We have no memory of future events to reference and see it as a whole. [If you cant, than there is no real point to talk about determinism because determinism requires you to determine one part of structure by other part, yet you have no meaningful way how to devide universe.] We can define a division. One could argue all is "one", but I have the ability to distinguish myself from a tree, or you, or any other thing. (True, there are some people that cannot do this or at least have a difficult time, that is an exception). One way to do this is to pick a scale to provide divisions. Example: At the supercluster level in the Universe, Earth is not distinguishable, on a planet scale, it becomes definable. Example: Life in general is chemical reactions, but say provide a scale of complexity, and one way life can be defined by the complexity of those chemical reactions. [Lets say you break universe into frames of positions of particles. It is clear that...there is no point to talk about determinism.] I would argue that we ourselves are also part of the uncertainty. I have not found if they are others that think this, but just as life can be defined as an local decrease in entropy, minds can be seen as an imposition of a determination not party to the surrounding nondeterminism. [My interpretation]: If you are a D. Adams reader, one close analogy I think is why the Heart of Gold craft in HGttG series was able to change the probability locally, and it took an equal but chaotic device, the last edition of the HGttG to restore the "order" before the Heart of Gold interfered with Earth's destiny so the Vogan's could carry out their original order and destroy the Earth. The "cricket ball" that powered the craft was able to determine a different probability, but an observer outside would not be able to predict the changing of the unpredictable
I really like this channel because it isn't afraid to tackle really hard concepts. I won't say that I understand all of it but I'm glad I can finally understand the basics of such hard concpets.
Yes, I definitely enjoy the difficult concepts as well. I liked this video more than the one of the last two weeks, because it more directly discussed reality (instead of adding in a video game/silly concept). Just my opinion.
rachelle2227 Actually, let me give you a more serious answer. The audience governs what we do, to a large extent. If you want to see more of this type of episode, we could make it almost 100% of the lineup (and that would actually be my preference). BUT... the views have to support it. So... share it. Make this our most viewed video, and then we as a production team will have strong evidence of how to steer the show.
PBS Space Time As much as I love this channel, you might have over estimated your audience's intelligence for this video. It seemed really interesting and I was trying my best but I don't feel like I really understood anything. But hey, rather that than the opposite. I appreciate how you still tried to explain it in an understandable way for an audience who doesn't have a degree in physics. I might come back another time when I'm not as tired, hopefully I'll understand more.
Been watching space time religiously for about 3 years now, my favorite channel on UA-cam. Glad I finally found the playlists as I try to get more and more physics knowledge into my skull. The most fascinating aspect of modern physics is the fact that the speed of light says something about the maximum speed of causality.
So, I know that when the Spacetime Interval (S.I.) is negative, we call those time-like intervals, when S.I. is 0 we call them light-like intervals and when S.I. is positive we call those space-like intervals. I understand that space-like intervals are so far away from each other that interaction between them is impossible due to information among them cannot travel faster than the speed of light. But when that information has traveled for the required amount of time to reach the distances, S.I. has already turned negative and thus, they now agree on the sequence of events. I'm trying to get my head around as to what could happen that is in a space-time interval where events are not in the same order, or even if they can actually observe the same event. So, yes. My question is more about the space-like intervals and an example showing a space-like interval in action.
PabloCorinthian Well an example of events not occurring in order would be like you're at an intersection at night and after the light turns green, a supernova explosion occurs in the sky. Then when I ask which occurred first, you say the light turned green first then the supernova when in reality, the supernova explosion happened hundreds of years ago so technically it happened first. Now a space-like interval in action is impossible for most things because something would have to move faster than light unless you were space-time itself. So right after the big bang there was the extremely fast expansion of the universe called inflation. During inflation, the entire universe expanded so dramatically that the "edge" of the universe would have actually expanded faster than the speed of light. If you're space-time, you don't have a speed limit which is why they call it 'space-like'.
PabloCorinthian Sergio Garza's answer is not correct. The time delay in arrival of light is not what space-like vs time-like spacetime intervals is about. Let me try to answer your question with a simpler example. And Sergio, pay attention, b/c I think you're conflating two unrelated concepts... Get a friend. Stand 1 meter apart. Agree to each clap your hands on the count of 3. 1.. 2... 3... clap! Ok, according to both of you (since you two are not in relative motion, you'll agree), the clapping events were simultaneous. But if I'm walking past the two of you, in the direction from you toward your friend, and I pass you just at the moment that you clap, then I will say that your friend (who I'm approaching) clapped *before* I passed you. In other words, before I pass you, the event of your friend clapping has *already happened* according to me, while according to you, it hasn't happened yet. At walking speeds, it would be a sub-femtosecond chronological disagreement between you and me, but a disagreement nonetheless. So I would say your friend claps before you clap. You'd say he clapped at the same time as you clapped. Yet neither of us is mistaken. The order of those events simply isn't a fact about the world because... the spacetime interval between those events was space-like. Chronological sequence is only a fact for events that are light-like or time-like separated. There you go. A commonplace everyday pair of events with a space-like interval b/w them. In fact, any two events that anybody says are simultaneous have a space-like spacetime interval b/w them. Remember, spacetime intervals exist b/w pairs of *events*, not b/w pairs of *locations*. Points in spacetime are *events*, not *locations*.
Alright. A bit clearer. So in order to experience a difference in events in a space-like interval requires motion to occur? Can such event happen within stationary observers?
PBS Space Time Yeah he's right, I was combing two different concepts I was thinking of at the same time. I guess I've had a really long day today. My bad!
Sergio Garza No worries! I know you're well-intentioned, and usually you have pretty good comments. Pablo -- you're still missing it (which is normal, b/c this is subtle). The spacetime interval b/w events is whatever it is, regardless of who's doing the looking. In the hand-clapping example, the interval b/w your clap and your friend's clap was spacelike. What the (relative) motion of an observer does is change how that interval is "distributed", for lack of a better term, into separate spatial and temporal separations. So... to you, the temporal separation b/w the events is zero (you say they were simultaneous) and the spatial separation is 1 meter. But I'm moving relative to you, so I will get different distances and time elapsed b/w those same events (as it turns, I will say the distance b/w the events is *less than 1 meter* and that your friend's clap occurred some tiny fraction of a second before your clap). So we disagree about distance b/w the events and about time elapsed b/w the events (and, in this case, we also disagree about the order). But we agree on the value of (delta-x)^2 - (c * delta-t)^2, and both of us say that spacetime interval is the same positive number. The point of the video is that even though we need to make measurements of distance and time in order to infer the spacetime interval (just like in 8th grade algebra class we had to know x and y coordinates of points in order to compute blackboard distances b/w them), the spacetime interval b/w those events has an objective existence independent of any of us having measured it (just like points on the 8th grade blackboard have a certain distance b/w them no matter how you draw an x-y grid on that blackboard). And the sign of the spacetime interval (which, again, is an objective quantity that's just out there whether or not any of us measure it b/w a given pair of events) tells you whether any time measurements that anyone may have made b/w those two events would have always agreed on chronology. If the spacetime interval is time-like or light-like, then any possible time measurement that anyone could have made b/w those events would agree about their order (though not about the amount of elapsed time b/w them). If, instead, the spacetime interval is space-like, then some observers making time measurements will say that event A occurred first, some will say event B occurred first, and some will say the events were simultaneous. So it's not that motion is a prequisite to experiencing temporal and spatial discrepancies just b/w spacelike events. Rather, it's a prerequisite to experiencing temporal and spatial discrepancies b/w *any* events (observers at rest relative to each other always agree about all issues of space and of time separately). It's just the case that, in the case of events with space-like separations, observers in relative motion are able to disagree about one added temporal aspect of those events that they would not be able to disagree about if the events were light-like or time-like separated, namely the event *order*.
Finally, this video reminded me why I've subscribed to your channel - I was kinda disappointed with the last few topics. Amazing stuff, guys, keep it up!
Nathan Lang you're officially a science prodigy congrats! I can't wrap my head around it,I'll stick to seemingly more rational concepts(rational to me anyway:) )
It kind of makes sense-I mean, to a particle on the edge of an event horizon, if that particle were able to look at Earth, as that particle accelerates to the speed of light when entering the black hole, every event that could possibly happen on Earth will unfold almost instantaneously. And we know that particle is at the edge of the black hole as I type this. So to me, my time is unfolding slowly and that particle isn't going anywhere. But to that particle, I'm old news, dead "trillions of years" already (quoting Startalk, I think). So I'm just a line with birth and death all at once. :)
Hawking's Brief History of Time is a great way to gradually ease into this sort of stuff, very well written. He gets onto spacetime around halfway through and then proceeds to blow your mind even further :D
Cameron Eacret Quantum physics, space-time, etc. are top of the food chain levels of science. Hard for people with backgrounds in science to understand. Start with the basics, like everyone else, and go from there. You'll be glad you did.
YeH Cameron You just need to go to basics if You dont understand something.Like You i love science too Quantum Realm and Space Time they are so great topics.And yes i am only 16 year old.So i sometimes get stuck and then i go scavenging for answers on UA-cam, Google or Quora..... Enjoy Your Journey Through The Fascinating World Of Science....😉😉😉😉😉😆😆😆👍👍👍👍👍👍
If everything just is, no past, present, future, how do we deal with the random nature of quantum processes? Their outcomes must be 'predetermined' as it were, but that removes the inherent randomness.
Gareth Dean I don't know much about this but I think that relativity and quantum mechanics don't get along. I'm pretty sure that we have yet to reconcile them in a definite manner.
tonyfalca While you are correct, at one point can you definitely say something is or isn't random? Perhaps there is a pattern, but it would take several magnitudes of the age of the universe for that pattern to become apparent? Is something only random if we can't prove it has an order?
this is overload on my brain. I've got a headache and am confused and I'm not even 4 minutes in. If I decide to be an astronomer, which I sort of do want to, God help me!
Renato Cara I want to be an astronomer but I'm not. Plus if I were, I'd learn this stuff step by step and then this wouldn't be confusing nor giving me a headache
This is barely Astronomy and almost (if not completely) pure physics. I'm interested in both astronomy and physics and I'm scared of what I'll have to understand!
+Renato Cara okay I'm an atheist and even I use terms like "Jesus, oh god," and so on but that usually doesn't tell you much about the persons religious views.
+Nic Ethan (NoobTubeGaming) well most of modern day scientists aren't and also back in a day society expected you to be religious and you usually would get laughed at or even suppressed
This video provides me with much needed hope as an atheist. It means that I've always existed living my life with my family, and I'll always be with my family for all of eternity ❤ Even if this particular theory isn't true, there is still a chance that there may be an afterlife with my family, or some other theory that involves my family could be true. There is hope!
Yes...we can't grasp the concepts of zero or infinity; we are trapped in a binary world of non-existence and existence. The universe is currently beyond our feeble understanding, but we must keep trying...
"your future isn't predetermined, it already exists", does that mean that all the choices and decisions I make rn, no matter what, will lead me to that already existing future?
5:28 onwards: You're conflating a useful mathematical structure with ontological reality. There is no reason to suggest "we *are* the line segment", as opposed to "we are moving along the line segment". In other words, relativity does not invalidate the reality of time, nor does it imply determinism. Like you, I once took the 'block universe' analogy literally, but then I thought about it from first principles (i.e. the relativity of simultaneity).
RELATIVITY IS INCOMPLETE AND NEEDS TO EXPLAIN BLACK HOLES AND GRAVITY ALSO DARK ENERGY ALL RELATED TO INNER WORKING OF NEUTRON STAR WITH BLACK HOLE ATTACHED QUASAR BLACK HOLE A UNIVERSE WITH ENERGY OF THE NEUTRINOS ALSO THEIR CONFIGURATION AND GRAVITY WITHIN TELL THIS GUY TO STOP WAVING HIS HANDS AND TAKE NOTICE OF QUANTUM AND NATURE,
As the universe is expanding, what is happening to time? Is this also 'growing'. Does that mean that Time travel to the past is impossible purely because 1 sec of 'new time' would not fit into 1 sec of 'old time'? And if time is growing while the universe is expanding, does that mean that we are always adding 1 sec to history, making it impossible to timetravel? It might be a weird and dumb question, but this time thingy got me all like "but what if".
FrasierCraft so I can't answer perfectly because I'm not actually an expert on this topic. I just happen to had Astronomy in High School like 2 years ago tbh :D But my teacher back then taught us, that time travel is simply impossible because one cannot move faster than time. (and I think time moves as fast as the speed of light does... correct me if I'm wrong!) So no matter how the universe expands ... if he is right, then we can't time travel anyways ;)
FrasierCraft Time is relative. No one knows yet if it's possible to travel through time (we can't walk freely through 4th dimension aka time) like we do in space. We can go right and left, up and down, but we're prisoners of time, we cannot go back and forth in that dimension, we're just constantly experiencing one moment after another. Inability to travel through time, doesn't mean that 's impossible. If we would able to control 4th dimension like 3d dimension, we'd see every event at the same moment. And that's the weird thing, basically our lives would have no point at all, because you always are alive, always go to school, always dead. It's impossible to understand 4th dimension right now, we can only see its concept in 3 dimensions, but that's like drawing a cube on the desk, it's still 2d. Maybe hundreds of years later we'll be able to go beyond time, to 5th dimension and so on. We can't add 1 sec to "history", because everything exists already. Universe expands because of our perception of life. It's already expanded and always born again beyond time. And that's just 4 dimensions out of 10 :) Existence is weird actually. It's possible that our universe is not the only one, there are infinity variations of it. If you're really interested, listen to Neil Degrasse Tyson talking about time and watch this video!!! /watch?v=zqeqW3g8N2Q
zamet95 FrasierCraft Sure we can time travel. Every time you walk you're travelling into the future. As well as every time you drive a car. The faster you go, the slower time travels for you relative to something stationary. This makes it technically possible to travel forward in time. However time travel backwards as far as we know is impossible. However, what the video is getting at is that time as a linear line is just an illusion. It's just there, just like zamet95 is getting at. It's there and doesn't change based on how we measure it.
I've heard this explained so that an 8 year old could understand it. He explains this stuff so fast its like he thinks his core audience already has a degree in Physics.
To add to the things he said at 3:12, there's a nice way to visualise the positive, zero and negative things that I learned from Stephen Hawking's A Brief History of Time. It's using a "light cone", which is an hourglass shape you can draw on a spacetime diagram with an event in the middle. Light would travel along the edge of the cone. Here's a picture: imgur.com/a/NG4Ns1a For the positive spacetime interval like A and B, the event is outside the cone and light can never reach it from A. They have no causal connection, neither event could possibly cause the other because there's no way for anything to get from one to the other. People disagree on the order of events like this. The way I drew it it looks like A happened first, but some other person moving a certain way would see B happen first. Another person could see both A and B happen at the same time. For a zero or negative spacetime interval, the event is inside the cone and light can reach it. So they do have a causal connection. In my picture, C is in the "future light cone" of A because A could "cause" or have an influence on C. Everyone agrees that A happened first in this case; no-one can see effect before cause. D is in the past light cone of A and everyone agrees that D happened before A. Since D is on the very edge of A's light cone, A and D have zero interval, while A and C have negative interval. Zero interval just means that only light-speed particles can travel from D to A. I'd love it if this clarified anything from the video, just wanted to share this because it helped me understand this stuff :D
I halfway understand. Basically time for us is an illusion and the past, present and future are all one thing. Because of our biological makeup and perceptive limitations we can only experience time as "moments" rather than see the whole thing at once.
5:37 quoting Alan watts that quoted zen master Dogen: Spring does not become summer, first there is Spring, then there is summer. In the same way the "you" of today does not become the "you" of tomorrow.
Is it normal that I'm having trouble understanding any of this? I consider myself pretty intelligent, but damn, this is some heavy stuff that is hard to keep up with.
+haydena357 It is perfectly normal that you are having trouble with this. I understood every word and even most of the phrases in this video but the links between the thoughts were very poorly explained in my humble opinion. Lots of assumptions were made that the viewer understood the connections being discussed and one bad explanation was tossed on top another bad explanation. I don't see any of the confusion being cleared up in the comments either.
+hotdrippyglass Yeah, I suppose only those who have put thousands of dollars into the education on such topics would really even have a chance of understanding in detail his explanations.
+haydena357 I have seen better explanations of the details to folks that have not been through an extensive education on this subject. I got the impression this was directed to students that have already been through four years of college level physics.
Same for me, its also told in a very short format, this guy speaks really fast. The information is presented in such a short time frame that i will have to watch it many times to make sense of it.
Excellent video. Philochrony is the theory that describes the nature of time and demonstrates its existence. Time is magnitive: objective, Imperceptible (intervals) and measurable.
Your entire life is a physical object. It's an ornament on the Christmas tree of some higher being in the 4th dimension. In fact the entire universe is, expanding and all. You only perceive it as being an unfolding event. But in reality (or at least the layer of reality in the 4th dimension), it's all already "there" as a solid object.
SevenFoot Pelican Let me try. Everything this guy said is a BS. Is it short enough? If not here is a slightly longer version. Space and time and spacetime do not exist as a material or physical objects. Why? Because they don't have any physical properties. None at all. No internal structure like a molecule or atom not even a particle. Try to google something like “is space or time material?” and you will find things like this - “When it comes to the notion of spacetime curvature, this is what General Relativity refers to. But under no circumstances should you conceive of space as though it's a material, physical thing; it isn't. Aug 11, 2018. Forbes › sites › 2018/08/11 › ask-et…“ That's why space and time can't do what material things can do like: bend, warp, dilate, etc. Instead they like some other things (dimensions, distance, volume etc) are a mathematical construct that we use for many purposes. And that's exactly what the guy in this video did.
"Imagine a hotdog bun. Now imagine that you took all the stars all the hundreds of stars there are in the universe, you take them and put them into a bag, and you put the universe into a bag, all the sudden, they become, uhm....."
"If you could put the universe into a tube, you'd end up with a very long tube -- probably extending twice the size of the unvierse, because when you collapse the universe, it expands and uh...you wouldn't want to put it into a tube."
k98killer if you put the universe in a tube, then in a sense the tube is the universe and the universe is the same size it has always been-the size of the universe
Loved this. I am a physicist by education, so I suppose that helps. But I love it when smart folks challenge these simplistic models we have for a metric, time, that we made up.
this is why history or past events repeats itself and if you want to understand how it will likely event will lead to another events, it is important that you will look unto the past events based on how you saw it from others
Hey hey hey, the subject is intriguing and interresting, but please try to slow down a little! You don't have to talk like a teenage video blog, I think people will manage to keep their attention a few minutes without this frenzy that would make Eminem jealous. Also, some of the flashing illustrations actually disturb more than they help, due to seconds exposed and graphical effects.
Invest your time and attention. When you finally start BEGINNING to understand some of this, it really is one of the best feelings. UA-cam is your friend and that occasional acid trip to fire up that curiosity within you ;)
I look at this from a totally different perspective. Everything around you from your own body to the entire cosmos, is an individual interpretation of your eternal conscious soul. One may ask 'An interpretation of what?'. Well the answer to that is, 'An interpretation of waves of potential possibillities'. And the nature of waves of possibillities is this. Imagine that a black hole has nothing but a surface, almost like a soap bubble. The surface of this bubble consists of nothing but information of everything that ever fell into the black hole. In fact is is a border of what we call reality, sometimes called the event horizon. This black hole surface is also in a so called state of 'singularity'. This means that all the information stored on the black hole's surface is spread out all over the entire surface. The surface is continiously checking its homogeneity by sending waves from any point of the surface to any other point of the surface and the shortest way for thes waves to travel is not over the black hole's surface, but diagonal right through the inside of the hole. If you're still with me here, you can understand that these traveling waves, are waves of all potential possibillities. If you have heard about the Double Slit Experiment, you may know that conscious obeservation is actually collapsing these waves of potental into what we call the material reality. So your consciousess is creating your individual experience of reality inside a black hole. So, It's no wonder that you and I can have slightly different measurement of time and location, is it? Yours and my own consciousness must be sharing a common source thou.
Drew Hayden That's actually a pretty good way of interpreting it. Many physicists love Slaughter House 5 for that reason aside from how funny it is. haha
I'm excited for this SR-GR stuff! What I thought was really cool and weird in General Relativity is when you're deriving the Robertson-Walker metric and you have to derive the curvature tensor, you have to use the surface of a 4 dimensional hypersphere to derive the curvature in spherical 3-D space. My question is how does non-locality fit into this?
Sergio Garza "you have to use the surface of a 4 dimensional hypersphere to derive the curvature in spherical 3-D space" You sure about this? I think you can read the curvature on the constant-t spacelike 3D hypersurfaces right off the FRW metric.
PBS Space Time Yes but when you're deriving the full metric the way R&W did it, you need to find curvature K for the curvature tensor. In doing so, you have to use the surface of a hypersphere and substitute it into the equation for the distance between two points in 4D space to eliminate the 4th dimension. From there you get the 3D space interval with curvature K in spherical coordinates with K = (1/a^2) with positive curvature.
Sergio Garza Ohhhh. I don't think you mean the "curvature tensor", i.e. the Riemann tensor. I think you mean the "Gaussian curvature", a scalar quantity defined at every point of a geometric space and that, in the case of a hypersphere, is constant (same value at every point). Unfortunately, the word "curvature" gets used in umpteen different ways in differential geometry and GR, so it's easy to miscommunicate. But now I get what you're talking about.
PBS Space Time Yes! Yeah, curvature is the name of the game and it really is everywhere. That's actually really subtle I never noticed before, I'll definitely keep that in mind during my studies!
Non-locality is essentially saying you, or what you currently experience as Self, is much like a being whom having never seen a radio would assume the voice in the box is the person rather than the Signal. Non-locality is the Unified Field of intelligence in which we embody under an illusion of duality and whats more- How, Who, What, When and Why you Truly are. You are not the Body, You are not the Mind... We are ;)
What I understood: The space and time without the forces, energies and matters are impossible to calculate. What we call spacetime is actually space time interval, causality, interaction between forces, energies and matters. The other stuff he said about past present and future and the book examples are speculations at this point I seems. For example, think of the time difference around the world. it's monday in US and Tuesday in Australia? Does that mean they live in the future? No we all live in the present but our time is based on rotation of the earth relative to the sun.
What baffles me is death. If I only perceive this one never ending moment as several linear moments in time then I haven't been born, I'm living and I've died. But when I die I'll still be alive. ??? Does this mean that somehow I will be alive but not aware of it? Or does this mean my perception starts all over again? Almost leads one to believe that consciousness may be unattached to any one specific time. I'm confused. ???
BuckeyeBoyz Grewell I think part of the issue is that we don't understand enough about consciousness right now either. Some peoeple think it's somewhere in the physical brain, others believe it to be a combination of all or multiple parts of the brain simultaneously, while others frankly believe in a soul. How can we understand the nature of death and time when we hardly understand the nature of time and don't understand what it means to be "alive?" I'm going to take a leap here and say that people are using human life spans and consciousnesses as examples to illustrate concepts but in reality these are conditions studied in reference to particles and the other extremely smalls.
***** +Mathew Smith so then as I have imagined and thought before, "free will" is just perceived. The way I have always explained it is, if our past brought us to our present, then you can say that our past has "decided" our present. And since our present is perceived as the past, to our future, you can say that our present "decides" our future. And therefore our past "decides" or determines our future. So you can safely say, that if there only ever was one past, then there can only ever be one future. So like you said in the video our past, present and future all already exist and there is nothing we could ever do to change any of them. We are just "participating in a never ending game of turning these particles into the next logical state". Essentially just reactions to things that already exist and "are". I'll explain it this way. Just like if you set up a set of mirrors all around in 3 dimensional space (our world would be 4D. But for sake of argument and understanding, this is only a 3D space). But set up these mirrors in such a way (however you imagine) with no variables in conditions, always the same. (ie no changes in wind gravity, angles, dust or any changes at all). Set them up in no particular "line" or "order" (this setup of mirrors would be our pre-existing pre-determined 4D universe), and point a laser at any one mirror somewhere in the middle, from any specific point, it will have a given path and the light will only travel along that path. (your timeline and "consciousness") Shine the light on a different mirror from a different angle, and you get a different path. (Somebody else's timeline and "conciousness"). But no matter how many times you point it at the same mirror, from the exact same angle as before, you will get the exact same path. Just a reaction, (a "causation" if you will) of what's already there. There would be other angles that you "could have" pointed from that would change the trajectory of the laser and change its path, but due to the layout and position of the mirrors, those angles would never and could never happen. So those "could have" paths are just that, "could have"s. Never were, never will, and never actually "could have" been. "Could have"s and "what if"s don't exist. Everything is, was, and always will be. Am I on the right track? This has been my theory for a few years now. I just now, for the first time ever, wrote it all down... I'm kinda proud of this idea. I think I might share...
***** I would agree with your statement "all things are all there. Potentially being done all ways at all time". BUT, my point a out that was, that due to the arrangement of the mirrors, your path would never follow in any other pattern than the one it is on. Possibility or not, it's NOT really a possibility at all... "Posibilities" couldn't actually exist in this world. It could never make a right turn at that point because the mirror at that point is pointed left. The "past" actions of thing have caused the set up to be as it is at that given "time". I quote "paths" and "time" because in this theoretical world, these things are an illusion. We only perceive them as existing due to us being on a "path" heading in a direction, and we call that "time". Now if the laser had reflected off of a different mirror prior to hitting this (fork in the road) mirror, then yes, it would have hit a different part of the mirror, or a different mirror entirely, causing the light to head in a different direction when it came into contact a that specific fork mirror. However, that is exactly my point. It would have had to initially come from a different angle or trajectory, in order for the laser to hit said fork mirror and head in a different path. So something prior would have to be different in order for the present to be different. Further pointing out, that the only way to change a path, is for it to have been changed previously. The past directions of the laser dictates its current path and it's current path dictates its future. So the only way to change a path is to change the original position and trajectory of said laser, which could have only been dictated by its "past" which would have been dictated by ITS "past" over and over again. So you could never really change that lasers path. Now if we added an element to this theory and said that some lasers could affect others by turning them or switching them on or off, then we could have new "paths" and many of them. We could say that each new path is a different path or "posibility". But that's just pushing the thought back one, only to delay the same conclusion. Because again we would see that yes this laser took a "new" path because it was affected by another laser, "changing" it's original trajectory. But in fact, it was always so. Let me explain. Because when the first laser originally set off on its path, it was headed in one, and only one, direction, and that direction was destined to turn the other laser and point it in a different direction (however so slight). So even tho this laser has been changed from where it was pointed before, what we "thought" was it's original path, was just an assumption due to our lack of foresight. We failed to see some of the previous lasers that were already in affect and existence. Even though we thought we knew that it was going to go in that direction, we were wrong and miscalculated. It was never actually going to go that way due to past events that had an affect on the present. There are too many variables for a human mind (or even a super computer) to predict the future. But only because we song know all the answers. We would have to know exactly what to plug in for all of these "variables". Not that they Can't be filled. They're not really variables at all, just "possibilities" to us due to our lack of omnipotence. Its too large of an equation to know all the numbers to fill in, but that doesn't mean they aren't there. We just don't have the capacity or ability to find them yet. No matter how you look at it, the future is dictated by the present, the present by the past, and the past by its past and so on. Forever to infinity.... And that brings me to another theory... The 4d fabric of "timespace" must turn back around on itself. Caused by itself in a sempiternal cycle. Eternal, unchanging and everlasting.
I really like this guy. I can follow his speed and words a lot easier than the slow guy. I got this the second time. It's easier if you've read any sci fi.. or at least watch Dr who. ☺
This explains why you have those who believe in their own subjective realities and thier own experiences, those who beleive in finding out the causal connection between events in the physical world, and those who believe consciousness causes these events(universe is all mental) Disagreement is a reoccuring theme as well lol
I always have in mind that the future is already written and we are just flowing within our current timeline of events. For example, we are on a vinyl record with all music already on it. And we are the current needle passing through the groove until the record ends (or in the biological case, until we die). We are flowing through predetermined timeline of events.
Bassotronics That's called determinism, I thought the same once when I was a kid, but now I've changed my mind. When you add quantum mechanics in it, you'll see that events don't evolve into just one scenario, and the observer affects the result. Now that's based on extremely small scale particle observation, but reality is made off small particles. So I agree with what's said in this vid that events are already "written" in relation to a specific timeline, but as a being who experience reality from a specific angle, in space time, it's only one temporary perspective. Cause and effect works, but it works like as if you were standing on a branch of a tree which hypothetically has an infinite height. When you work your way upwards (how you experience time right now), all paths are already there based on the principles of cause and effect, but you have a choice. Just my opinion, I'm no expert.
Romanov 1917 "This guy (donno which guy you referring)" is saying that things are bound to happen in certain ways, and people have certain influence in choosing which one happens. Like when you are at a crossroad, you have the free will to take which ever road available, but you can't just fly up if that's what you want. Whatever is happening is bound by causality. And causality is not like a simple A => B, but A => perhaps infinite amount of results. It's all about possibilities.
Zetoto I disagree with that. In spacetime, our lives are line segments, as pointed out in the video. Our future is absolutely, 100% fixed, just like our past. The universe works the same in both directions, it's just that we humans can only look in one direction, and that's backwards. We can't look forward, into the future, and that's what creates the illusion of time "passing". But I don't get why people think this destroys free will. Just because you have already made your future decisions, they're still YOUR decisions. You made them with your conscious mind. Your timeline is fixed, yes, but you're still the one who fixed it that way.Make this life good, because despite our intuition, we never get to leave. We're all stuck on loop.
Everybody wants an answer, something to hold on to and sience is the ultimate expression of that. I love this video, because of relativity/personality, there is no answer. So instead of asking what is, or who is, right/true; everybody/everything is.
+Michael Hutchinson I feel I getting a hunch, but not more - before my brain turns into SpaceJam every Time I watch such things. Sometimes I find connections, understand a bit more - and then start all vids over again I can find. Since years......
watched it 16 times
I think its about physics
isnt 16 a "perfect number"
Yo I think you’re onto something here
Lol...
best comment i have ever come across..
Maybe? are you sure? we have to do research on this video
Sitting on my bed, covered in blanket, rocking back and forth
"I am the line segment"
"I am the line segment"
"I am the line segment" ....
ahahaha xd
😂😂😂😂😂😂🤣🤣
3 years later. You still win the internet for the day. Haha
"I am the line segment"
"I am the line segment"
"I am the line segment"
"I AM the line segment"
"I AM THE line segment"
"I am THE LINE segment"
"I am THE LINE SEGMENT"
"I AM THE LINE SEGMENT"
...
"My God. That was strong."
This cracked me up
"this is just a loose introduction"
uhhhhh, anybody out there got a looser introduction?
Maybe we need the tight introduction...
daekry that’s what my ex said to me
The brain and the 5 senses are not designed to perceive and experience a 3-dimensional universe filled with matter that is flowing through time. Just the opposite, they are designed to create the illusion, the holographic simulation of such a 'reality'.
@@bradstephan7886 I think you're probably putting a little too much emphasis on "the brain and the five senses". Also, "a 3-dimensional universe filled with matter that is flowing through time" is exactly what our brains are designed to handle. They aren't designed to model large sections of it all at once like some kind of computer simulation, but that's not the issue here. The issue here is that the idea of objective space-time, where space and time are not independent of each-other, but rather just arbitrary axes we draw on maps of space-time based on our orientation in space-time (largely position and velocity), which we are inclined to use because that is the most useful way of modeling the space-time near us.
If you were to draw a Minkowski diagram with normal time and distance units (like, say, seconds and meters), which are both of sizes that are easily conceivable by humans, then the part of the graph between the speed-of-light lines to the right and left of the origin would have essentially no width, and it would be similar if the origin were moved to represent the perspective of any other point in the spacetime with such units. Similarly, all of the hyperbolas of equal spacetime-interval would look like straight lines. Thus, approximately speaking, the vertical axis gives spacetime-intervals (negative both ways), where each point can be a cause of any point above it (assuming this is a diagram where time flows up). (The spacial axes also give space-time-intervals, but always within margin-of-error of zero and thus without the causal relationship.) The space of events where none of them can have any causal influence on each other, looks approximately like a line. When we consider that a truly accurate Minkowski diagram would need 3 "spacial" dimensions to go along with the one "time" dimension, then we see that this "line" is actually a three-dimensional space, and if we were to take a very large number of slices with different "time"-coordinates (where every point in one slice had the same time-coordinate, which is technically relative, but would be approximately the same for every normal-velocity, remotely nearby-origined reference from), then every slice would have the potential to affect any remotely-nearby point in certain slices (those "after" it) and would not be able to affect others (those "before" it). This is our ordinary understanding of space and time, it is possible because, for some reason, causality does operate in certain directions of space-time and not others (i.e., special relativity does not show that space and time are interchangeable, at least not when we use our normal, causality-based understanding of time, rather than the "t"-coordinate in the Minkowski space, which is actually just something that mostly lines up to our idea of time, largely due to wrong assumptions we make about the way things "move" through (or "exist" in) space and time).
What is actually most weird about this (or at least what is least well understood) has nothing to do with the relationship between space and time, but rather the nature of causality; specifically, "what is the difference between cause and effect, between time viewed as going 'forwards' and time viewed as going 'backwards'". Clearly there is a difference, since we perceive that time only goes in one direction, and certain laws, specifically the law of thermodynamics that says that all things lead twards entropy, care about the direction of time, but it is also possible to logically deduce causes from there effects (this the fundamental basis of our memories of events), just as well as it is possible to logically deduce effects from causes (and in fact it is not entirely possible to do either, because of quantum uncertainty, which can only be turned into deterministic physics if you use the "many worlds" interpretation and accept that the position of your "current" "self" is somewhat random, which might come in the somewhat questionable form of neglecting the validity of these ideas of "now" and "self").
As for our "brain" and "5 senses" being "designed to perceive and experience" things a certain way, I think it's analagous the directions forward, backward, right, left, etc. It's easier to think of positions in the field of view simply as directions relative to the eye, as referenced by which photorecepter cells on the retina are fired; however, in order to understand the spaces we live in when our eyes move, we must have an understanding that space is independent of our viewpoint, which can be achieved by knowing how to transform the various coordinate systems so that we can imagine looking spaces stored in our mind from whatever direction we want in our "minds eye". (Yes, this is an overly vision-based explanation, and there are more senses involved and I probably haven't given a great description of how spacial information is stored in brains, but it's just a demonstration of the idea.) Our intuitive understanding of space and time being different is completely serviceable under all of the normal Earth-like conditions we evolved in, and in which everyone grew up in as children and spends most of their lives in, so there has generally been no incentive to put resources into developing these more abstract relativistic spacetime models in our brains. Thus, it is extremely difficult to train oneself to be as comfortable with these ideas as we are with spacial ideas that have been necessary for the survival of us and our ancestors for hundreds of millions of years.
daekry Yea google “spacetime doomed” that’s the best introduction you can get right now.
When he said he'll take it slow, I kind of felt relaxed. But then came French.
that language triggers a fight or flight response, so I understand
Lmfao
I hate that I am intelligent enough to find this subject absolutely fascinating but too stupid to grasp any of it.
Just find some text resources and try. I'm sure you'll figure it out with enough time.
@Red Rat you obviously didnt understand the video.
read brian greene's "the elegant universe", i promise it will greatly clarify things for you.
Stagger Lee
It took Einstein 10 years to fully understand General relativity. Be patient my friend, your get there in the end. Start right from the beginning, study special relativity first. It’s not lack of intelligence, it’s just gaps in your knowledge that are the problem.
Thre things. 1 Everyone has this problem with grasping General Relativity concepts. The smartest and brightest do and it's normal. 2 Even if you are able to open your mind and accept for the sake of listening and learning, 'real life' and intuitive activities eventually 'bleed in' and contradict and we have to revisit and 're open' our minds. 3 I strongly suggest that all of those here and elsewhere who 'claim' to understand it and accept it are being honest with us or themselves. I do not believe that even those who define this stuff can easily set aside intuition and real world experience. Baloney. They constantly have to 're convince' themselves of the laws of physics as the truth and put intuition aside.
It hurts, it really does hurt to not fully understand this. Bro I don't wanna die without understanding this :(
after the 5th time or so i got it, but the problem is that this is a really big topic and he is really trying to bring it on point, i guess it's no problem that one isn't understanding it in the first attempt :)
you just need to familiarize yourself with a few basic concepts of relativity. its actually a lot simpler than it looks and is so intresting, its insane. Just look up a little about "time dilation"(with speed or gravity) and the double slit experiment.
+Nxrv how does the double slit experiment relate to relativity?
+Daniel It shows the importance of an observer, maybe?
...how time works (or doesn't work) prove exactly that there is no NEED for God . :)
science and God can be put in the same sentence, but science and organized religion cannot.
Me: Alright I'm smart enough to watch this.
5 minutes later: How did I get here.
Watch the Netflix series dark
Space and time are illusions. Nothing travels faster than light. Because of this, information cannot travel faster than light. That means that people in the Andromeda galaxy in their "present" probably see something very different in our (us in the Milky Way's) present. Because of this fact, the only thing that exists are the events we can observe between the illusions of space and time (ie. our planet evolving from one of dinosaurs to human life in the telescopes of an observer in the Andromeda galaxy). Knowing space (even if expanding) and time (relative, but not always agreeable) are illusions, causality is the only thing that is real. Basically even though it feels like our whole life is playing out in "reality" from a 3 dimensional sense, it could in fact just be a "physical object" (our whole lives birth to death, the creation and eventual end of the universe, etc.) in a higher, 4 dimensional space.
Imagine the 2 dimensional characters in movies we watch on screen truly believing that their lives and actions in the movie are real and playing out in real time, as opposed to having already being determined for them, in our 3 dimensional world.
I tried telling my pension company my future already exists so can I get my pension payment now.
They said no.
hoogmonster I guess they said no because you already received it..
@@Adrianvim stupidity
They should have just said that they're already giving it to you in the future.
Did you explain entanglement?
They said "no", because just like reality, your pension provider deals in probabilities, not line segments.
okay the video is 9 minutes long but it took me 3 hours to finish watching it. i guess time really is relative
GeneticFreak GRD+
I found it easier to understand after I've slept, as with everything I want to understand. I think the mentioned "3 hours" is better spent watching it on as many separate days as you can. Idk why, but something about sleeping...
Hey.....that is why I love time....it is the only thing which is challenging me!!!!!
It's taken three years, but I finally think I understood everything he says here.
Watched it a year ago. I understood very little. I understand most of what he says now. I recommend you a book called The Order of Time. It explains it a little bit better.
fabian5002 thank you, I was able to understand most of what he said vs basically none of it a year ago, yet still needed to put a fair amount of conscious effort into the fabrication and holding of these concepts in my mind for the purpose of comprehension and cross-reference. I would love to get to the point where I am able to do this process automatically without having to put any conscious effort into it. Much like holding a metaphorical cup whose shape is foundational knowledge that I no longer notice while holding, so that I may focus explicitly on the contents therein of additional knowledge. This book may be the variable that finally allows me this ability, so I will definitely check it out.
Hello, maybe you could help me to understand one issue. I came here after watching some videos from PBS, and studying philosophy, pondering about issues of time expressed by McTaggart in his article "On the unreality of time", Henri Bergsons conception of subjective time, Humes inquiry about causality, sometimes exploring posibilities to incorporate Leibnizian geometrical monadological aproach. If there is no time, no change and there is just atemporal spatime geometrical fields of events, how it is possible for the guy in video to talk about causality? I can understand how events can be interconected and how can one event point to other if you look on them as constituents of one bigger event. But this seem that one event contains other just contextualy and not substantialy, this is not the hardest issue here. The big thing i dont understand is how can concept of causality work without concept of change because clasical conceptualization of causality works with terms like effect and cause and those indicitates that one event (in the past) authoritatively determines the other in future. But if you have no real change, how can you say that one event is determining other and not oposite way, nor that both determines one another relatively? For what it seems to me people often spoke of determinism as something oposing free will, thinking that past determines future, but to me it seems like such concept of determinism is misunderstanding. Maybe history of universe can be coherent geometrical arangment without change and without past determining future, but with both coexisting and being ordered in a greater coherent structure. But it can be nonsense to think of some part of structure as more free than other. It seems to me that theory of relativity is actually geometrical theory and so can be apriori (concept of pure reason) but this theory does not determine existence of one or other universe, it just provides framework for which universes are possible, which are nonsense, It gives us rules how to build universe but allows many arangements. Now i know that one concept plays a lot with concept of arangment, it is entropy. For some reason entropy is always incresing so it seems like one of those rules for buyilding universes is that it starts with lowest enthropy and it ends with biggest, every universe shares the same big bang as there is only one microstate in big bang but diferentite in the Last moment of biggest entropy because this can have miximum number of microstates. Maybe universe has to be stretch between those to extremes, because at least idea of time, there has to be continuity of similarity, the first and last moments of universe are very diferent but if you give other moments between them in specific arangment, you can create something that seems like continuity of similarity and maybe this continuity of similarity is what theory of relativity can in part describe. Also with regard to entropy, it seems understandable why people think of past as determining future rather than oposite way. Because in any given moment, there is way less more possible pasts than futures and if principle of reversibility is right, than there is just one past. And then when we see whole universe as one single coherent thing yet knowing there was one only possible singularity on one side, big number of possible heat deaths on the other and thanks to the fact that more the two possible heat deaths are simmilar, more simmilar past in form of universe history share, and because what is samé in those histories is always in past but what is diferent is in its future, thats may be how illusion of one way causality is born while in fact there is no causality in this meaning, just causal coherency but no causal determinations. Also in quantuum physics in copenhagen interpretation if you dont measure what happened between two states, you conclude that all possible things happened. It is like saying that there is no real history set between those two states, there exists only those states alone, and by saying what is all possible histories going between them we just say, how simmilar and diferent are those states from one another. But we have many ways how to look on them and how to conceptualize their similarity, therefor we have many possible continusites between them, so if you really want to precise the one exact continuity, you need to include it in another relationship to something other, the more things the relationship is between the more precise it becomes. It can be that substance of space which defines it, are pointa yet only what can really bear some quality is relationship of those points and their diatancies, so by this the qualities are qualities of space.
So this was longer than i expected, what i realy want from you guys is to explain me, how the guy in video works with term causality here. Thank you for your answer and for reading this, have a nice day
Martin
hello Sheldon i am pretty confused because (causality) by reading your post you seem like a very smart being but then you ask this kind of questions in the youtube comments section! (entropy) @@martinpavlicek2299
@@ivoten LOL i dont understand. It may be useless but why not, sometimes i share such questions on reddit or quora, sometimes with my classmates. It is not so clever, just lots of talk.
Have a happy and nice new year
It felt like watching a movie in a foreign language with subtitles in Chinese
Yes😂
Space and time are illusions. Nothing travels faster than light. Because of this, information cannot travel faster than light. That means that people in the Andromeda galaxy in their "present" probably see something very different in our (us in the Milky Way's) present. Because of this fact, the only thing that exists are the events we can observe between the illusions of space and time (ie. our planet evolving from one of dinosaurs to human life in the telescopes of an observer in the Andromeda galaxy). Knowing space (even if expanding) and time (relative, but not always agreeable) are illusions, causality is the only thing that is real. Basically even though it feels like our whole life is playing out in "reality" from a 3 dimensional sense, it could in fact just be a "physical object" (our whole lives birth to death, the creation and eventual end of the universe, etc.) in a higher, 4 dimensional space.
Imagine the 2 dimensional characters in movies we watch on screen truly believing that their lives and actions in the movie are real and playing out in real time, as opposed to having already being determined for them, in our 3 dimensional world.
I don't like the way this guy talk. Why so much muscle movement on his mouse?
Oh, c'mon it really isn't that difficult.
JUst need to watch it over and over again
I rewatched it 7 times pausing at literally every second just to grasp any sentence he said and I know that I'll never watch it enough
Tbh I feel some of the things weren't explained very well, unless you already understand it he didn't fully explain many of the ideas he brought up.
He is nothing but a scammer who's objective is to use fast talk,mostly lies but a little truth to confuse you.Why? He is using the same techniques taught to salesman,not scientists.
@@jymfysher7704 That's what it appears to you because you lack the background knowledge to understand it. Unlike scams and cults, all the knowledge needed to understand this video is available in math and physics textbooks. Source: I'm an engineer.
@@cosmic_gate476 Ya you got me ! I never could pass math 10 so my math skills are very lame.But I been watching Sobine (The German quantum physicists) and her teaching methods make much more sense to me.Maybe that's becouse school\textbook math should be called a form of calculus or agreed upon system compared to a modular system (No one ever consulted me before teaching me things that just aren't always true !) So I try to understand your textbook math but had many teachers like the guy in this video who seem to go very quickly when explaining things that I find questionable as if there is no need to ponder what he says,just believe becouse he knows so,as you do too !!
who was lost at the definition of spacetime
🖐️
He didn't really define spacetime, that "definition" simply pointed it out, identified it as the reality where we can "sense" or experience both space and time between objects and events
Space and time are illusions. Nothing travels faster than light. Because of this, information cannot travel faster than light. That means that people in the Andromeda galaxy in their "present" probably see something very different in our (us in the Milky Way's) present. Because of this fact, the only thing that exists are the events we can observe between the illusions of space and time (ie. our planet evolving from one of dinosaurs to human life in the telescopes of an observer in the Andromeda galaxy). Knowing space (even if expanding) and time (relative, but not always agreeable) are illusions, causality is the only thing that is real. Basically even though it feels like our whole life is playing out in "reality" from a 3 dimensional sense, it could in fact just be a "physical object" (our whole lives birth to death, the creation and eventual end of the universe, etc.) in a higher, 4 dimensional space.
Imagine the 2 dimensional characters in movies we watch on screen truly believing that their lives and actions in the movie are real and playing out in real time, as opposed to having already being determined for them, in our 3 dimensional world.
@@SevenFootPelican Thank you so much.... I finally was able to grasp this concept after reading your explanation. This just opened up so many doors for me
😅😅
"If you pay attention this episode is going to blow your mind"
Oh good I'm safe then
I don't know about other, but knowing the concept of spacetime actually give me a lot of comfort.
It means everyone you lose you never actually loose them, they are still ”there” in the fabric of spacetime
Yeah I'm down with that. Nothing lasts but nothing is lost.
'This is challenging for everyone, even Einstein."
Stoners: Hold our beer.
LEGIT
Or bong
📠📠📠
Yea I got it first time around. Or should I say, I already know it when it happens.
let me try to help all of you (even myself): the focus on this video it is about reality, OK? The true nature about reality is something that everyone can agrees. If two observers measure somethink and the values of the measurement doesn't match, and still true for both observers separately, it can means two things: thoes observers lives in two paralel's reality, with diferent laws to rule the time and space OR the 'experiense' of reality (events measurement) for both DO NOT correspond to the true and universal nature of reality. And how thoes observers measures reality? counting time and measure space (1D Time and 3D space). If thoes quantities do not match, it means counting time and measure space are NOT the fundamental measurement of reality. Reality is something that both observers can agree. And both agrees about spacetime intervals. That means one thing: probably, spacetime interval is the true measurement of reality, common to both observers without need to invoke two paralel's reality occuring simultaneously. In a nutshell: Time and space are not the reality. time and space are just consequences of this global concept call spacetime, which we perceive as reality in our brains by 3D space and vivid passage of time. The SpaceTime concept is the true nature of reality. Whith this concept understood, the rest of the video is much more clear (to me, at least). I hope I've helped, and sorry about english. Try to explain something that is dificult by itself In a non-maternal language is hard as hell
Good summing up of what this video is trying to get at. Too many commenters watched the video, remember the ending, and forget the important disclaimers, provisos, and guidelines laid down in the first 3 minutes.
Excellent recap
humans consider itself intelligence, no one else said it, just us...so are we even consider intelligent creatures by real intelligence that is out there, that is laughing at us? maybe we are not. but since no one came to us and graded us and teach us and tell us where we stand in the universe. we just have to do it ourselves. so whatever we understand and know is the best we got...space is the emptiness all around you and time is a dimension of itself for information to tell where your at in that given space of time. Einstein said time is relative to the observer, so that means time moves in different speed, depending on the awareness of that observer...space and time isn't set to everything to move in the same speed. so reality itself that space and time is a part of, is just the thing you see and can understand.
If we call it spacetime not space and time than indeed we can't measure space and time separately
@@nesseihtgnay9419 there not laughing.
I think the problem for all of us trying to understand this comes down to grasping the below concepts in combination with each other and finding an example in everyday life in conjunction with space and time to understand it properly forever.
1 Confusion about future, past and present being different for different people
2 Relation with light.
3 Why should we consider space time together always when we have a clear distinction between them on earth and dont need to refer to the other necessarily.
I'll try to explain it with a simple example based on my understanding of how everything fits together .
There are two people Ana and Rick standing in front of each other in London.Rick sees that Ana is eating an apple at 3:00 pm . She finishes eating it at 3:05 pm. That is Rick's present that he sees
that Ana is done eating the apple at 3:05 pm. Now you may think that this is also Ana's present but actually it is NOT. Rick sees Ana
because the light is reflected of Ana and enters Rick's eyes. However the speed of light is 300000000 m/s so it is virtually taking almost ZERO time
to enter Rick's eyes once its reflected from Ana. So what Rick sees as Ana's present , Ana also agrees with that . However there is a very very very very minute time lapse which is negligible.
Now imagine that Ana suddenly gets teleported to New York city and Rick has a big telescope to see Ana. She now eats a banana at 4:00 pm
and finishes eating at 4:05 pm . Again , their present and past SEEM TO MATCH because of the very very very negligible time difference
leading them to believe that its all happening in the present. Now Suddenly Ana gets teleported to a PLANET X from which it takes light 2 minutes
to reach Rick's giant telescope. Now Ana is eating an orange (exactly at 5:00 pm on both earth and PlanetX) and finishes eating it at 5:05 pm . However since light now takes
2 minutes because of the massive distance in space , Rick will not see that Ana has finished eating the orange at 5:05 pm but will see it
at 5:07 pm . So at precisely 5:05 pm Ana will say that she has finished eating the orange but Rick will continue to see that Ana is eating
the orange . So Rick's present is Ana's past . (Similary for future which i will leave upto you to relate !)
So when they were in London standing in front of each other , their present and past differed by approximately 0.000000000000000001 sec and hence couldnt see the differnce and didnt agree it was different
When they where in New York City , their present and past differed by approximately 0.000000000001 sec and hence couldnt see differnce again and didnt agree that it was different
However with Ana being very far away on a PlanetX, their present and past differed by 2 minutes and boom..they both agreed immediately since now their brain could comprehend that delay in time.
This is how the space and time are always bound together no matter where we are. Its just that when light travels so fast, we cannot understand
the impact one has on the other for defining past, presence and future.
This is the best i can come up with. If I am wrong in my explanation, then do not crucify me !
I like your story about Ana the fruit-eater and Rick the Ana-observer.😂 However, it only explains the delay of events observed over a distance due to the limit of the speed of light, but did not explain the constriction and dilation of space and time, and the differences in the order of events, that are mentioned in the video.
In your story, even though Rick sees Ana finishes eating the orange at 5:07 pm, he should also see her starts eating at 5:02 pm, so the duration of the event is still the same for both Ana and Rick, that Ana spends 5 minutes to eat that orange.
The weird thing about reality is that different observers can see different distances between two events, different durations between and of the events, and even see the events happening in different orders.
Suppose Rick has a big enough telescope to observe Ana eating a cucumber on a planet orbiting a black hole. She starts eating at 6:00 pm and ends at 6:05 pm according to her own clock. Even though she spends 5 minutes in her perspective, Rick will observe the event happening in slow motion and taking a much longer time than 5 minutes, because of the immense gravitational field of the black hole. In contrast, if Rick also spends 5 minutes to eat a cucumber, Ana will see it happening in fast motion and taking much less time than 5 minutes. This is an example of an event having different durations in different observers' perspective.
Perception does not equal present reality.
you explains such events about ana and rick story but even you have no idea or no supplement of instruments which can achieve for you this theory of yours that if Rick also spends 5 minutes to eat a cucumber, Ana will see it happening in fast motion and taking much less time than 5 minutes. This is an example of an event having different durations in different observers' perspective.,i am hoping you all stop that cause its waste of time itself not even anyone can be able to invent time machine to go back in time to see his dead father again neither this reality can change that because when living your father have on memory of some bazaar individual he meet in past who looks like his son then how can we travel back in time to let father have this memory . this means that upcoming many years there is no guarantee of time machine actually invented ,there might be some strange experiments was did by under government support but chances of success are all o % there is no time traveler nor anything successfully being made but research goes on.
I dont think ana can teleport, since rick has The portal gun and can go anywhere faster than ana. Also, you would also see morty freaking out saying, "aww geez rick what the hell are you doing"(like if you get that)
I like chicken nuggets
I love how you can come back to a video like this multiple times and each time experience a fresh revelation of understanding, a slightly different more developed perspective
nah you dont
I don't even remember which of these videos I watched.
I can watch any of them again and not realize I've seen it.
damn I am rewatching this again and I feel your comment! The first time I watched this was four years ago and I can still get a different perspective from it
I came here to say this. Let’s just say the only other times that I actually had the feeling of, “omg is this real” involved acid. I didn’t realize how trippy GR is, now I’m hooked.
Parrell I think that with the bibel bc time and new stuff has happened so it carries r mind into unum a new understanding (unnumbered )
Teacher: why didn't you finish your homework last night
Me: I was outside the causally connected point
"We have to crawl before we walk." I feel like I am not yet born for this stuff.
I've got a headache by watching this video. That means it time to go to bed and process al this.
I honestly didn't know how to spell "that" after watching this .
Rien B. my brain hurts so much i feel like screaming
Watching this video causes a blank space to form between your ears.
I got a odd felling in my frontal lobe cos time is an illusion
Yes It's time to fill your head with true knowledge instead of youtubeein bull pucky, get that feeling. lol
hahah I failed physics three times in high school because it never really interested me but I watched a 2min video about spacetime when I was high last night and now I have legit questions about spacetime and physics in general thanks to the internet. So I guess, thank you guys for making me interested in science stuff again
Lol... you said stuff
High.
Boring teachers kill our interest in any topic. My teachers of civics and history literally put me to sleep, so I hated both and learned nothing.
you failed physics and decided to watch space time ..... i dont think id evr do that
@camila Stefanie....no offence but three times?
The very best analogy I've ever heard for the concept that all points in time exist simultaneously was from a book called "Illusions" by Richard Bach.
One of the characters explained to another that time is like a movie on one of those theater movie reels. The whole movie is there simultaneously for the projectionist. It only appears to flow to the characters in the movie. I read that book over 30 years and that one description has stuck with me all this "time".
It's not a science book, btw. It's a short fiction .So don't crack on me if you buy it thinking it was :)
I think the analogy of a vinyl record works even better
@@i_so_late Why would it work better? They're the same example, except a movie reel has visual motion in addition to the audio. If anything, the movie reel is "better"
I read "Illusions" when I was 17yrs old. Reading that book opened a door in my mind that has led me thru a labyrinth of other doors over a lifetime. Had I not read it, I may have never known those doors even existed. Thank you, Richard Bach
Now imagine that reel splitting into two reels from each point on that an measurement is made.
You lost me at Causality
he lost me at 00:00
same
Same, I still don't understand the term *causality* and how it impacts time
Its The Speed of Light.
Causality is information from 2 or more relationships on a World Line.
One way I see of understanding it, is if you got back to the past, try to kill Hitler, yet you only become an instrument in his rise to power and shape the history that we already know. Events happen as they always happened, just not in chronological order.
This is the one video that changed (or at least sparked the flame to change) the way I see life and reality forever. I hope I can thank Gabe personally one day
Step 4: ???
Step 1: Profit
Step 3: Understand this video
Step 2: Be born
In that order.
Nah fam, my order is different
You have 4 steps? I have 23.
You guys have a step 1?
too bad this violates causality
We don’t all need to agree on the order
This has to be one of the best expositions of spacetime that I've seen (apart from the still at 5:47 where the text isn't tenseless, "already" implies in the past but it is describing the future).
This is the best video I have ever seen that explains something to people who already know the topic before watching it.
Well I already know the topic and I still didn't get it, so perhaps not.
@ThisIsMyRealName ngl had to look up the word infotainment
An accurate burn.
I think you are saying every single second of my life is being lived at once .inherently I am being born and am dying simultaneously with every other experience I have ever experienced .I just am there is no real end and there was never a real beginning.time is really just a mental invention to make us feel we are keeping track .maybe we just go on forever and ever and those that we know to have died are living their life in another plane from what we perceive to be here and today. I need to take another hit of my joint.see you soon and again and again and again.
Exactly
every stage of your life can be seen in any order via a number of reference points
[I think you are saying every single second of my life is being lived at once]
You yourself are not living all your life at once, at least, you perceive in space and in time. Now, if you could "see" spacetime, and was an observer outside of spacetime, you would in essence be seeing a sort of panoramic of your life. Instead of experiencing the flow of time or the feel of movement, you could look from left to right along that spacetime view and see different parts of your life.
If say you had a cosmic filmstrip, say a super 8inty strip (play on super 8 :) ) and it was about 25 milliseconds per frame (cannot remember what the brain frequency of its perception of reality is right now), you could point to any frame and "see" that part of life, but to experience it, you would have to be in that frame and not able to view frames ahead and with some memory of those from before
@@agimasoschandir If you really understand this explain me one thing: The guy in video mentions causality, yet he says there is no separete time and change only spacetime. So if causality is relationship between effect and cause, how can there be any without change in time? I can understand that certain event can relate to other event if they are both part of bigger event and relate to one another in context of that event but than, how can you say which event causes which? Does past causes future or does future causes past or is it relative or both?
The question is if you can devide the whole of universe into moments or if you must take it as one indevisible spacetemporal entity. If you cant, than there is no real point to talk about determinism because determinism requires you to determine one part of structure by other part, yet you have no meaningful way how to devide universe. If you devided this unity in your mind like if you dived movie into frames, than you broke those rules mentioned in video. Lets say you break universe into frames of positions of particles. It is clear that to determine the future positions of particles you do not only need to know their positions in presence but also all of their energy and vectors to say where they will move next and how will they interact. But Heisenbergs principle of uncertainity says that object cant have exact position and velocicity measured in once, it is incoherent to describe both to one object. So you have only two options really you can break universe into moments but than you lost information about energy in it or you give up on deviding it and determining exact position of particles, leaving it being spacetemporal objects but than there is no point to talk about determinism.
@@martinpavlicek2299
[If you really understand this ...]
Did not specify what I might understand, but in general, I do not.
[So if causality is relationship between effect and cause, how can there be any without change in time?]
I am unsure why you are proposing there is no change in time. Time is a measurement taken by the observer in their frame. Time and space measurements taken by an observer in a different frame of reference will measure the event differently from another inertial frame (not a frame of a film or video).
[Does past causes future or does future causes past or is it relative or both?]
We humans have a perception of time happening one way because we have a reference point to measure from what event was the cause and what event was the result, and eventually, a knowledge of related events that tell us the most probable "before" and "after" event. That is not to say other creatures may not, I am using humans in reference to "we".
[The question is if you can devide the whole of universe into moments or if you must take it as one indevisible spacetemporal entity]
We order our lives by referencing the "now". We have no memory of future events to reference and see it as a whole.
[If you cant, than there is no real point to talk about determinism because determinism requires you to determine one part of structure by other part, yet you have no meaningful way how to devide universe.]
We can define a division. One could argue all is "one", but I have the ability to distinguish myself from a tree, or you, or any other thing. (True, there are some people that cannot do this or at least have a difficult time, that is an exception). One way to do this is to pick a scale to provide divisions. Example: At the supercluster level in the Universe, Earth is not distinguishable, on a planet scale, it becomes definable. Example: Life in general is chemical reactions, but say provide a scale of complexity, and one way life can be defined by the complexity of those chemical reactions.
[Lets say you break universe into frames of positions of particles. It is clear that...there is no point to talk about determinism.]
I would argue that we ourselves are also part of the uncertainty. I have not found if they are others that think this, but just as life can be defined as an local decrease in entropy, minds can be seen as an imposition of a determination not party to the surrounding nondeterminism.
[My interpretation]: If you are a D. Adams reader, one close analogy I think is why the Heart of Gold craft in HGttG series was able to change the probability locally, and it took an equal but chaotic device, the last edition of the HGttG to restore the "order" before the Heart of Gold interfered with Earth's destiny so the Vogan's could carry out their original order and destroy the Earth. The "cricket ball" that powered the craft was able to determine a different probability, but an observer outside would not be able to predict the changing of the unpredictable
I really like this channel because it isn't afraid to tackle really hard concepts. I won't say that I understand all of it but I'm glad I can finally understand the basics of such hard concpets.
Yes, I definitely enjoy the difficult concepts as well. I liked this video more than the one of the last two weeks, because it more directly discussed reality (instead of adding in a video game/silly concept). Just my opinion.
rachelle2227 But farts and zombies are so much fun!
rachelle2227 Actually, let me give you a more serious answer. The audience governs what we do, to a large extent. If you want to see more of this type of episode, we could make it almost 100% of the lineup (and that would actually be my preference). BUT... the views have to support it. So... share it. Make this our most viewed video, and then we as a production team will have strong evidence of how to steer the show.
PBS Space Time As much as I love this channel, you might have over estimated your audience's intelligence for this video. It seemed really interesting and I was trying my best but I don't feel like I really understood anything. But hey, rather that than the opposite. I appreciate how you still tried to explain it in an understandable way for an audience who doesn't have a degree in physics. I might come back another time when I'm not as tired, hopefully I'll understand more.
PBS Space Time Not saying I didn't like the video, it might just be a little too abstract and complex for a large audience, including myself.
Been watching space time religiously for about 3 years now, my favorite channel on UA-cam. Glad I finally found the playlists as I try to get more and more physics knowledge into my skull. The most fascinating aspect of modern physics is the fact that the speed of light says something about the maximum speed of causality.
so have i already watched this video orrrrrr?
Good one....
What about the view counter o.o
i was always going to comment here, so here I am, commenting here....
I actually knew you watched this before you did. But you only watched it for 5 sec. You might say otherwise. Who knows?
If I don't agree then that's a no my friend :)
I understand some of these words.
So, I know that when the Spacetime Interval (S.I.) is negative, we call those time-like intervals, when S.I. is 0 we call them light-like intervals and when S.I. is positive we call those space-like intervals.
I understand that space-like intervals are so far away from each other that interaction between them is impossible due to information among them cannot travel faster than the speed of light. But when that information has traveled for the required amount of time to reach the distances, S.I. has already turned negative and thus, they now agree on the sequence of events.
I'm trying to get my head around as to what could happen that is in a space-time interval where events are not in the same order, or even if they can actually observe the same event.
So, yes. My question is more about the space-like intervals and an example showing a space-like interval in action.
PabloCorinthian
Well an example of events not occurring in order would be like you're at an intersection at night and after the light turns green, a supernova explosion occurs in the sky. Then when I ask which occurred first, you say the light turned green first then the supernova when in reality, the supernova explosion happened hundreds of years ago so technically it happened first.
Now a space-like interval in action is impossible for most things because something would have to move faster than light unless you were space-time itself. So right after the big bang there was the extremely fast expansion of the universe called inflation. During inflation, the entire universe expanded so dramatically that the "edge" of the universe would have actually expanded faster than the speed of light. If you're space-time, you don't have a speed limit which is why they call it 'space-like'.
PabloCorinthian Sergio Garza's answer is not correct. The time delay in arrival of light is not what space-like vs time-like spacetime intervals is about. Let me try to answer your question with a simpler example. And Sergio, pay attention, b/c I think you're conflating two unrelated concepts...
Get a friend. Stand 1 meter apart. Agree to each clap your hands on the count of 3. 1.. 2... 3... clap! Ok, according to both of you (since you two are not in relative motion, you'll agree), the clapping events were simultaneous. But if I'm walking past the two of you, in the direction from you toward your friend, and I pass you just at the moment that you clap, then I will say that your friend (who I'm approaching) clapped *before* I passed you. In other words, before I pass you, the event of your friend clapping has *already happened* according to me, while according to you, it hasn't happened yet. At walking speeds, it would be a sub-femtosecond chronological disagreement between you and me, but a disagreement nonetheless.
So I would say your friend claps before you clap. You'd say he clapped at the same time as you clapped. Yet neither of us is mistaken. The order of those events simply isn't a fact about the world because... the spacetime interval between those events was space-like. Chronological sequence is only a fact for events that are light-like or time-like separated.
There you go. A commonplace everyday pair of events with a space-like interval b/w them. In fact, any two events that anybody says are simultaneous have a space-like spacetime interval b/w them. Remember, spacetime intervals exist b/w pairs of *events*, not b/w pairs of *locations*. Points in spacetime are *events*, not *locations*.
Alright. A bit clearer. So in order to experience a difference in events in a space-like interval requires motion to occur? Can such event happen within stationary observers?
PBS Space Time
Yeah he's right, I was combing two different concepts I was thinking of at the same time. I guess I've had a really long day today. My bad!
Sergio Garza No worries! I know you're well-intentioned, and usually you have pretty good comments.
Pablo -- you're still missing it (which is normal, b/c this is subtle). The spacetime interval b/w events is whatever it is, regardless of who's doing the looking. In the hand-clapping example, the interval b/w your clap and your friend's clap was spacelike. What the (relative) motion of an observer does is change how that interval is "distributed", for lack of a better term, into separate spatial and temporal separations. So... to you, the temporal separation b/w the events is zero (you say they were simultaneous) and the spatial separation is 1 meter. But I'm moving relative to you, so I will get different distances and time elapsed b/w those same events (as it turns, I will say the distance b/w the events is *less than 1 meter* and that your friend's clap occurred some tiny fraction of a second before your clap).
So we disagree about distance b/w the events and about time elapsed b/w the events (and, in this case, we also disagree about the order). But we agree on the value of (delta-x)^2 - (c * delta-t)^2, and both of us say that spacetime interval is the same positive number. The point of the video is that even though we need to make measurements of distance and time in order to infer the spacetime interval (just like in 8th grade algebra class we had to know x and y coordinates of points in order to compute blackboard distances b/w them), the spacetime interval b/w those events has an objective existence independent of any of us having measured it (just like points on the 8th grade blackboard have a certain distance b/w them no matter how you draw an x-y grid on that blackboard). And the sign of the spacetime interval (which, again, is an objective quantity that's just out there whether or not any of us measure it b/w a given pair of events) tells you whether any time measurements that anyone may have made b/w those two events would have always agreed on chronology. If the spacetime interval is time-like or light-like, then any possible time measurement that anyone could have made b/w those events would agree about their order (though not about the amount of elapsed time b/w them). If, instead, the spacetime interval is space-like, then some observers making time measurements will say that event A occurred first, some will say event B occurred first, and some will say the events were simultaneous.
So it's not that motion is a prequisite to experiencing temporal and spatial discrepancies just b/w spacelike events. Rather, it's a prerequisite to experiencing temporal and spatial discrepancies b/w *any* events (observers at rest relative to each other always agree about all issues of space and of time separately). It's just the case that, in the case of events with space-like separations, observers in relative motion are able to disagree about one added temporal aspect of those events that they would not be able to disagree about if the events were light-like or time-like separated, namely the event *order*.
6:33 "So why do we perceive reality in such a vividly spatial and temporal way?"
Immanuel Kant would like a word.
haha
ua-cam.com/video/u5DgUcsTfxY/v-deo.html
I was about to write something about Kant.
Lots of words, really, some of which he made up just to make the argument possible.
you should have said enters the chat.
6:57 a wiseman once said. some times you gotta run before you walk
+3dmoddeler haha this explains this video clearly!
+3dmoddeler
Don't strike until the iron is hot, but make it hot by striking.
Once, or will say, or is saying?
Good quote.
Is that Tony Stark?...
The wise man ?
I'm at uni studying theoretical physics because of this channel
How's the study coming along?
Finally, this video reminded me why I've subscribed to your channel - I was kinda disappointed with the last few topics. Amazing stuff, guys, keep it up!
"Even though we can't agree about past, present, future, time, or distance, we all appear to agree about causality."
Some of us agreed to question reality of everything after watching this video. "we agree that we don't agree about anything"
F*ck, i'm dumb.
+Djanck000 i feel you bro,i love science but this is some next level shit
+andrea simoncini you guys aren't dumb, this is like the hardest shit in all of science. Just keep with it.
+electrocat1 i kinda figured a lot of this a few years ago. kinda awesome to know the math to it and that im not the only one that has these thoughts.
Nathan Lang yep
Nathan Lang you're officially a science prodigy congrats! I can't wrap my head around it,I'll stick to seemingly more rational concepts(rational to me anyway:) )
It kind of makes sense-I mean, to a particle on the edge of an event horizon, if that particle were able to look at Earth, as that particle accelerates to the speed of light when entering the black hole, every event that could possibly happen on Earth will unfold almost instantaneously. And we know that particle is at the edge of the black hole as I type this. So to me, my time is unfolding slowly and that particle isn't going anywhere. But to that particle, I'm old news, dead "trillions of years" already (quoting Startalk, I think).
So I'm just a line with birth and death all at once. :)
Kewl, bro.
No ur saying opposite actually, u r not insanely fast for that particle but instead infinite slow,more like a frozen statue for it
@@onelunchman6979 You should read up on how relativity works to get a better understanding of what I"m saying.
Ur comment actually made sense to my low number of brain cells.
I was so confused this entire video and its pissin me off cause science interests me I just can't fucking understand it 😒
Hawking's Brief History of Time is a great way to gradually ease into this sort of stuff, very well written. He gets onto spacetime around halfway through and then proceeds to blow your mind even further :D
:D :D :D
Cameron Eacret Quantum physics, space-time, etc. are top of the food chain levels of science. Hard for people with backgrounds in science to understand. Start with the basics, like everyone else, and go from there. You'll be glad you did.
YeH Cameron You just need to go to basics if You dont understand something.Like You i love science too Quantum Realm and Space Time they are so great topics.And yes i am only 16 year old.So i sometimes get stuck and then i go scavenging for answers on UA-cam, Google or Quora.....
Enjoy Your Journey Through The Fascinating World Of Science....😉😉😉😉😉😆😆😆👍👍👍👍👍👍
Soldiers Forever mate...
0:22 "So we're going to take it slow"
If everything just is, no past, present, future, how do we deal with the random nature of quantum processes? Their outcomes must be 'predetermined' as it were, but that removes the inherent randomness.
Gareth Dean just because it may seem random to us doesn't necessarily entail that it is indeed random
Gareth Dean I don't know much about this but I think that relativity and quantum mechanics don't get along. I'm pretty sure that we have yet to reconcile them in a definite manner.
Nitsugalego
?? yeah, i neither know much about it but i believe you're right?
tonyfalca While you are correct, at one point can you definitely say something is or isn't random? Perhaps there is a pattern, but it would take several magnitudes of the age of the universe for that pattern to become apparent? Is something only random if we can't prove it has an order?
tonyfalca
Indeed, however there's some pretty good evidence it is, viz Bell's theorem. 'Local hidden variables' have been ruled out at least.
this is overload on my brain. I've got a headache and am confused and I'm not even 4 minutes in. If I decide to be an astronomer, which I sort of do want to, God help me!
If you are asking for a divine being to help you understand something, you should really reconsider doing science at all.
Renato Cara I want to be an astronomer but I'm not. Plus if I were, I'd learn this stuff step by step and then this wouldn't be confusing nor giving me a headache
This is barely Astronomy and almost (if not completely) pure physics. I'm interested in both astronomy and physics and I'm scared of what I'll have to understand!
+Renato Cara okay I'm an atheist and even I use terms like "Jesus, oh god," and so on but that usually doesn't tell you much about the persons religious views.
+Nic Ethan (NoobTubeGaming) well most of modern day scientists aren't and also back in a day society expected you to be religious and you usually would get laughed at or even suppressed
After seeing the video 16 times
I knew his name is gabe not game
underrated coment
Literally thaught his name was Greg smh
This video provides me with much needed hope as an atheist.
It means that I've always existed living my life with my family, and I'll always be with my family for all of eternity ❤
Even if this particular theory isn't true, there is still a chance that there may be an afterlife with my family, or some other theory that involves my family could be true.
There is hope!
Experiencing reality is beyond the capacities of our finite mind and brain.. How can finite know the INFINITE fundamental reality of everything ...
You're right. We can't.
Yes...we can't grasp the concepts of zero or infinity; we are trapped in a binary world of non-existence and existence. The universe is currently beyond our feeble understanding, but we must keep trying...
"your future isn't predetermined, it already exists", does that mean that all the choices and decisions I make rn, no matter what, will lead me to that already existing future?
🤯
so how are we moving forward in spacetime? Who is pressing the play button ?
Every possible outcome of your future exists. Even you becoming the president.
Everything is "happening" right now. Potentially there may variability as we all move between parallel timelines billions of times per second
5:28 onwards: You're conflating a useful mathematical structure with ontological reality. There is no reason to suggest "we *are* the line segment", as opposed to "we are moving along the line segment". In other words, relativity does not invalidate the reality of time, nor does it imply determinism.
Like you, I once took the 'block universe' analogy literally, but then I thought about it from first principles (i.e. the relativity of simultaneity).
RELATIVITY IS INCOMPLETE AND NEEDS TO EXPLAIN BLACK HOLES AND GRAVITY ALSO DARK ENERGY ALL RELATED TO INNER WORKING OF NEUTRON STAR WITH BLACK HOLE ATTACHED QUASAR BLACK HOLE A UNIVERSE WITH ENERGY OF THE NEUTRINOS ALSO THEIR CONFIGURATION AND GRAVITY WITHIN TELL THIS GUY TO STOP WAVING HIS HANDS AND TAKE NOTICE OF QUANTUM AND NATURE,
For the past year or so this show has whole heartedly convinced me my “doctorate” in law should have an “LOLz” permanently affixed to it!!!
Watch at .75 speed
haha
Was wishing for that feature! Will watch again at .5 I think
If you hold down the space bar, it comes close. I like to think of it as that flip book he mentioned.
Also watch it at 2x speed 😂
You've just created a warp in spacetime, you've created a time paradox, i'm watching this in 1997! Wooah
As the universe is expanding, what is happening to time? Is this also 'growing'. Does that mean that Time travel to the past is impossible purely because 1 sec of 'new time' would not fit into 1 sec of 'old time'? And if time is growing while the universe is expanding, does that mean that we are always adding 1 sec to history, making it impossible to timetravel? It might be a weird and dumb question, but this time thingy got me all like "but what if".
Could someone please answere this? Could not find any answeres online...
FrasierCraft so I can't answer perfectly because I'm not actually an expert on this topic. I just happen to had Astronomy in High School like 2 years ago tbh :D
But my teacher back then taught us, that time travel is simply impossible because one cannot move faster than time. (and I think time moves as fast as the speed of light does... correct me if I'm wrong!)
So no matter how the universe expands ... if he is right, then we can't time travel anyways ;)
FrasierCraft Time is relative.
No one knows yet if it's possible to travel through time (we can't walk freely through 4th dimension aka time) like we do in space. We can go right and left, up and down, but we're prisoners of time, we cannot go back and forth in that dimension, we're just constantly experiencing one moment after another. Inability to travel through time, doesn't mean that 's impossible. If we would able to control 4th dimension like 3d dimension, we'd see every event at the same moment. And that's the weird thing, basically our lives would have no point at all, because you always are alive, always go to school, always dead. It's impossible to understand 4th dimension right now, we can only see its concept in 3 dimensions, but that's like drawing a cube on the desk, it's still 2d. Maybe hundreds of years later we'll be able to go beyond time, to 5th dimension and so on.
We can't add 1 sec to "history", because everything exists already. Universe expands because of our perception of life. It's already expanded and always born again beyond time. And that's just 4 dimensions out of 10 :) Existence is weird actually.
It's possible that our universe is not the only one, there are infinity variations of it. If you're really interested, listen to Neil Degrasse Tyson talking about time and watch this video!!! /watch?v=zqeqW3g8N2Q
zamet95 Thank you very much for your answere! I really appritiate it :)
Same with yours Hanni!
zamet95 FrasierCraft Sure we can time travel. Every time you walk you're travelling into the future. As well as every time you drive a car. The faster you go, the slower time travels for you relative to something stationary. This makes it technically possible to travel forward in time. However time travel backwards as far as we know is impossible. However, what the video is getting at is that time as a linear line is just an illusion. It's just there, just like zamet95 is getting at. It's there and doesn't change based on how we measure it.
I've heard this explained so that an 8 year old could understand it. He explains this stuff so fast its like he thinks his core audience already has a degree in Physics.
i watched it on 2x speed it really wasnt hard to understand. Maybe it's because i've watched most pbs space time videos already.
To add to the things he said at 3:12, there's a nice way to visualise the positive, zero and negative things that I learned from Stephen Hawking's A Brief History of Time. It's using a "light cone", which is an hourglass shape you can draw on a spacetime diagram with an event in the middle. Light would travel along the edge of the cone. Here's a picture: imgur.com/a/NG4Ns1a
For the positive spacetime interval like A and B, the event is outside the cone and light can never reach it from A. They have no causal connection, neither event could possibly cause the other because there's no way for anything to get from one to the other. People disagree on the order of events like this. The way I drew it it looks like A happened first, but some other person moving a certain way would see B happen first. Another person could see both A and B happen at the same time.
For a zero or negative spacetime interval, the event is inside the cone and light can reach it. So they do have a causal connection. In my picture, C is in the "future light cone" of A because A could "cause" or have an influence on C. Everyone agrees that A happened first in this case; no-one can see effect before cause. D is in the past light cone of A and everyone agrees that D happened before A. Since D is on the very edge of A's light cone, A and D have zero interval, while A and C have negative interval. Zero interval just means that only light-speed particles can travel from D to A.
I'd love it if this clarified anything from the video, just wanted to share this because it helped me understand this stuff :D
I haven't got a clue what this video is about 😂
1st honest post i`ve read.
I'm glad I'm not the only one :)
I halfway understand. Basically time for us is an illusion and the past, present and future are all one thing. Because of our biological makeup and perceptive limitations we can only experience time as "moments" rather than see the whole thing at once.
+Mike Dole i fucking love this mad shit
im not sure thats something i would find funny
Thank you for posting equations and I very much do enjoy the format of your videos both from script to visual aids. Keep it up.
"You are the line segment". The most profound thing I've heard yet
5:37 quoting Alan watts that quoted zen master Dogen:
Spring does not become summer, first there is Spring, then there is summer.
In the same way the "you" of today does not become the "you" of tomorrow.
Who else paused the video more than 100 times ?
Is it normal that I'm having trouble understanding any of this? I consider myself pretty intelligent, but damn, this is some heavy stuff that is hard to keep up with.
+haydena357 It is perfectly normal that you are having trouble with this. I understood every word and even most of the phrases in this video but the links between the thoughts were very poorly explained in my humble opinion. Lots of assumptions were made that the viewer understood the connections being discussed and one bad explanation was tossed on top another bad explanation. I don't see any of the confusion being cleared up in the comments either.
+hotdrippyglass Yeah, I suppose only those who have put thousands of dollars into the education on such topics would really even have a chance of understanding in detail his explanations.
+haydena357 I have seen better explanations of the details to folks that have not been through an extensive education on this subject. I got the impression this was directed to students that have already been through four years of college level physics.
+hotdrippyglass Likewise.
Same for me, its also told in a very short format, this guy speaks really fast. The information is presented in such a short time frame that i will have to watch it many times to make sense of it.
Time doesnt create change. Change creates time.
+Robot HandLove Or our perception of time, as time as an entity may not exist.
FUCK YOU! WHAT A FUCKING AMAZING INSIGHT!
Literally what he said in the video.
Excellent video. Philochrony is the theory that describes the nature of time and demonstrates its existence. Time is magnitive: objective, Imperceptible (intervals) and measurable.
Can someone summarize this into a meme so I can understand it?
time is relative
bottom text
@rent a shill 😐
It's like all causality mannn
Your entire life is a physical object. It's an ornament on the Christmas tree of some higher being in the 4th dimension. In fact the entire universe is, expanding and all. You only perceive it as being an unfolding event. But in reality (or at least the layer of reality in the 4th dimension), it's all already "there" as a solid object.
SevenFoot Pelican Let me try. Everything this guy said is a BS. Is it short enough? If not here is a slightly longer version. Space and time and spacetime do not exist as a material or physical objects. Why? Because they don't have any physical properties. None at all. No internal structure like a molecule or atom not even a particle.
Try to google something like “is space or time material?” and you will find things like this -
“When it comes to the notion of spacetime curvature, this is what General Relativity refers to. But under no circumstances should you conceive of space as though it's a material, physical thing; it isn't.
Aug 11, 2018. Forbes › sites › 2018/08/11 › ask-et…“
That's why space and time can't do what material things can do like: bend, warp, dilate, etc. Instead they like some other things (dimensions, distance, volume etc) are a mathematical construct that we use for many purposes. And that's exactly what the guy in this video did.
"Imagine a hotdog bun. Now imagine that you took all the stars all the hundreds of stars there are in the universe, you take them and put them into a bag, and you put the universe into a bag, all the sudden, they become, uhm....."
+k98killer wat.
+k98killer m&m's?
It's a line segment.
"If you could put the universe into a tube, you'd end up with a very long tube -- probably extending twice the size of the unvierse, because when you collapse the universe, it expands and uh...you wouldn't want to put it into a tube."
k98killer if you put the universe in a tube, then in a sense the tube is the universe and the universe is the same size it has always been-the size of the universe
holy shit this video is helping me understand the ending of Interstellar so much
True, the only way to communicate in 4D is through gravity
physicists agree that the segments about general relativity generally make sense. the ending is purely fictional though.
oh shit that's true, about the tesseract :D
I am sorry to tell you but interstellar violates causality.
Loved this. I am a physicist by education, so I suppose that helps. But I love it when smart folks challenge these simplistic models we have for a metric, time, that we made up.
i always hated the expression:" time goes by so quickly". because to me, time doesn't go anywhere. it is we, who are going by.
We're not going by. We've already done the whole thing called life, haha.
When he says “fact” reminds me of Dwight
One of the best videos ever?
this is why history or past events repeats itself and if you want to understand how it will likely event will lead to another events, it is important that you will look unto the past events based on how you saw it from others
This is very Zen, but also very science and very math. One of the best SpaceTime episodes
So we are a four dimensional non euclidian thing that understands itself.
Nice
DonRobo *brain explodes*
Hey hey hey, the subject is intriguing and interresting, but please try to slow down a little!
You don't have to talk like a teenage video blog, I think people will manage to keep their attention a few minutes without this frenzy that would make Eminem jealous.
Also, some of the flashing illustrations actually disturb more than they help, due to seconds exposed and graphical effects.
loool
I’m interested in this stuff but don’t understand any of it so imma peace out
Invest your time and attention. When you finally start BEGINNING to understand some of this, it really is one of the best feelings.
UA-cam is your friend and that occasional acid trip to fire up that curiosity within you ;)
Throwing shade at toxic commenters?! Get me onboard
Relativity: claiming to go slow, presenting as fast as possible.
The animations are fire 🔥! Someone give the artist 🎨 a raise! Helpful in aiding understanding 💙
I have never ever, in my 15 years of UA-cam binge watching, seen something I did not understand even one percent of the whole - until I saw this video
I look at this from a totally different perspective. Everything around you from your own body to the entire cosmos, is an individual interpretation of your eternal conscious soul. One may ask 'An interpretation of what?'. Well the answer to that is, 'An interpretation of waves of potential possibillities'. And the nature of waves of possibillities is this. Imagine that a black hole has nothing but a surface, almost like a soap bubble. The surface of this bubble consists of nothing but information of everything that ever fell into the black hole. In fact is is a border of what we call reality, sometimes called the event horizon. This black hole surface is also in a so called state of 'singularity'. This means that all the information stored on the black hole's surface is spread out all over the entire surface. The surface is continiously checking its homogeneity by sending waves from any point of the surface to any other point of the surface and the shortest way for thes waves to travel is not over the black hole's surface, but diagonal right through the inside of the hole. If you're still with me here, you can understand that these traveling waves, are waves of all potential possibillities. If you have heard about the Double Slit Experiment, you may know that conscious obeservation is actually collapsing these waves of potental into what we call the material reality. So your consciousess is creating your individual experience of reality inside a black hole. So, It's no wonder that you and I can have slightly different measurement of time and location, is it? Yours and my own consciousness must be sharing a common source thou.
In a way it kind of reminded me of how the Tralfamadorians view humans in Slaughter House 5.
Drew Hayden That's actually a pretty good way of interpreting it. Many physicists love Slaughter House 5 for that reason aside from how funny it is. haha
When I was five I had thoughts about nonlinear time being a book being read simultaneously on all pages
ua-cam.com/video/u5DgUcsTfxY/v-deo.html
Are Space and Time an Illusion?
Me: *hits blunt
I'm excited for this SR-GR stuff! What I thought was really cool and weird in General Relativity is when you're deriving the Robertson-Walker metric and you have to derive the curvature tensor, you have to use the surface of a 4 dimensional hypersphere to derive the curvature in spherical 3-D space. My question is how does non-locality fit into this?
Sergio Garza "you have to use the surface of a 4 dimensional hypersphere to derive the curvature in spherical 3-D space" You sure about this? I think you can read the curvature on the constant-t spacelike 3D hypersurfaces right off the FRW metric.
PBS Space Time Yes but when you're deriving the full metric the way R&W did it, you need to find curvature K for the curvature tensor. In doing so, you have to use the surface of a hypersphere and substitute it into the equation for the distance between two points in 4D space to eliminate the 4th dimension. From there you get the 3D space interval with curvature K in spherical coordinates with K = (1/a^2) with positive curvature.
Sergio Garza Ohhhh. I don't think you mean the "curvature tensor", i.e. the Riemann tensor. I think you mean the "Gaussian curvature", a scalar quantity defined at every point of a geometric space and that, in the case of a hypersphere, is constant (same value at every point). Unfortunately, the word "curvature" gets used in umpteen different ways in differential geometry and GR, so it's easy to miscommunicate. But now I get what you're talking about.
PBS Space Time
Yes! Yeah, curvature is the name of the game and it really is everywhere. That's actually really subtle I never noticed before, I'll definitely keep that in mind during my studies!
Non-locality is essentially saying you, or what you currently experience as Self, is much like a being whom having never seen a radio would assume the voice in the box is the person rather than the Signal. Non-locality is the Unified Field of intelligence in which we embody under an illusion of duality and whats more- How, Who, What, When and Why you Truly are.
You are not the Body, You are not the Mind... We are ;)
What I understood:
The space and time without the forces, energies and matters are impossible to calculate.
What we call spacetime is actually space time interval, causality, interaction between forces, energies and matters. The other stuff he said about past present and future and the book examples are speculations at this point I seems. For example, think of the time difference around the world. it's monday in US and Tuesday in Australia? Does that mean they live in the future? No we all live in the present but our time is based on rotation of the earth relative to the sun.
Boom!!!!!
CONFUSED.
😂😂😂
This is the best intro to space time that I have seen yet. I finally get it!
What baffles me is death. If I only perceive this one never ending moment as several linear moments in time then I haven't been born, I'm living and I've died. But when I die I'll still be alive. ??? Does this mean that somehow I will be alive but not aware of it? Or does this mean my perception starts all over again? Almost leads one to believe that consciousness may be unattached to any one specific time. I'm confused. ???
BuckeyeBoyz Grewell I think part of the issue is that we don't understand enough about consciousness right now either. Some peoeple think it's somewhere in the physical brain, others believe it to be a combination of all or multiple parts of the brain simultaneously, while others frankly believe in a soul.
How can we understand the nature of death and time when we hardly understand the nature of time and don't understand what it means to be "alive?"
I'm going to take a leap here and say that people are using human life spans and consciousnesses as examples to illustrate concepts but in reality these are conditions studied in reference to particles and the other extremely smalls.
LeSean Payne
Well ... that is the most intelligent sounding answer I think I've ever received on that question.
***** oh no ... it was very well written. I think that you are correct. I just wish we could find a way to observe much more than 80 years or so.
*****
+Mathew Smith so then as I have imagined and thought before, "free will" is just perceived.
The way I have always explained it is, if our past brought us to our present, then you can say that our past has "decided" our present. And since our present is perceived as the past, to our future, you can say that our present "decides" our future. And therefore our past "decides" or determines our future. So you can safely say, that if there only ever was one past, then there can only ever be one future. So like you said in the video our past, present and future all already exist and there is nothing we could ever do to change any of them. We are just "participating in a never ending game of turning these particles into the next logical state". Essentially just reactions to things that already exist and "are".
I'll explain it this way. Just like if you set up a set of mirrors all around in 3 dimensional space (our world would be 4D. But for sake of argument and understanding, this is only a 3D space). But set up these mirrors in such a way (however you imagine) with no variables in conditions, always the same. (ie no changes in wind gravity, angles, dust or any changes at all). Set them up in no particular "line" or "order" (this setup of mirrors would be our pre-existing pre-determined 4D universe), and point a laser at any one mirror somewhere in the middle, from any specific point, it will have a given path and the light will only travel along that path. (your timeline and "consciousness") Shine the light on a different mirror from a different angle, and you get a different path. (Somebody else's timeline and "conciousness"). But no matter how many times you point it at the same mirror, from the exact same angle as before, you will get the exact same path. Just a reaction, (a "causation" if you will) of what's already there.
There would be other angles that you "could have" pointed from that would change the trajectory of the laser and change its path, but due to the layout and position of the mirrors, those angles would never and could never happen. So those "could have" paths are just that, "could have"s. Never were, never will, and never actually "could have" been. "Could have"s and "what if"s don't exist. Everything is, was, and always will be.
Am I on the right track? This has been my theory for a few years now. I just now, for the first time ever, wrote it all down... I'm kinda proud of this idea. I think I might share...
***** I would agree with your statement "all things are all there. Potentially being done all ways at all time". BUT, my point a out that was, that due to the arrangement of the mirrors, your path would never follow in any other pattern than the one it is on. Possibility or not, it's NOT really a possibility at all... "Posibilities" couldn't actually exist in this world. It could never make a right turn at that point because the mirror at that point is pointed left. The "past" actions of thing have caused the set up to be as it is at that given "time". I quote "paths" and "time" because in this theoretical world, these things are an illusion. We only perceive them as existing due to us being on a "path" heading in a direction, and we call that "time".
Now if the laser had reflected off of a different mirror prior to hitting this (fork in the road) mirror, then yes, it would have hit a different part of the mirror, or a different mirror entirely, causing the light to head in a different direction when it came into contact a that specific fork mirror. However, that is exactly my point. It would have had to initially come from a different angle or trajectory, in order for the laser to hit said fork mirror and head in a different path. So something prior would have to be different in order for the present to be different. Further pointing out, that the only way to change a path, is for it to have been changed previously. The past directions of the laser dictates its current path and it's current path dictates its future. So the only way to change a path is to change the original position and trajectory of said laser, which could have only been dictated by its "past" which would have been dictated by ITS "past" over and over again. So you could never really change that lasers path.
Now if we added an element to this theory and said that some lasers could affect others by turning them or switching them on or off, then we could have new "paths" and many of them. We could say that each new path is a different path or "posibility". But that's just pushing the thought back one, only to delay the same conclusion. Because again we would see that yes this laser took a "new" path because it was affected by another laser, "changing" it's original trajectory. But in fact, it was always so. Let me explain. Because when the first laser originally set off on its path, it was headed in one, and only one, direction, and that direction was destined to turn the other laser and point it in a different direction (however so slight). So even tho this laser has been changed from where it was pointed before, what we "thought" was it's original path, was just an assumption due to our lack of foresight. We failed to see some of the previous lasers that were already in affect and existence. Even though we thought we knew that it was going to go in that direction, we were wrong and miscalculated. It was never actually going to go that way due to past events that had an affect on the present.
There are too many variables for a human mind (or even a super computer) to predict the future. But only because we song know all the answers. We would have to know exactly what to plug in for all of these "variables". Not that they Can't be filled. They're not really variables at all, just "possibilities" to us due to our lack of omnipotence. Its too large of an equation to know all the numbers to fill in, but that doesn't mean they aren't there. We just don't have the capacity or ability to find them yet.
No matter how you look at it, the future is dictated by the present, the present by the past, and the past by its past and so on. Forever to infinity.... And that brings me to another theory... The 4d fabric of "timespace" must turn back around on itself. Caused by itself in a sempiternal cycle. Eternal, unchanging and everlasting.
I really like this guy. I can follow his speed and words a lot easier than the slow guy. I got this the second time. It's easier if you've read any sci fi.. or at least watch Dr who.
☺
This explains why you have those who believe in their own subjective realities and thier own experiences, those who beleive in finding out the causal connection between events in the physical world, and those who believe consciousness causes these events(universe is all mental)
Disagreement is a reoccuring theme as well lol
I am obsessed with this subject, this channel, and now...spacetiem
I try to understand but after watching for 2 hours I still can’t open my Pop-Tart.
we are calling our perception a reality thinking everyones perception is of absolute and find significance in it.. we are funny frogs in our wells.
I always have in mind that the future is already written and we are just flowing within our current timeline of events. For example, we are on a vinyl record with all music already on it. And we are the current needle passing through the groove until the record ends (or in the biological case, until we die). We are flowing through predetermined timeline of events.
Bassotronics That's called determinism, I thought the same once when I was a kid, but now I've changed my mind. When you add quantum mechanics in it, you'll see that events don't evolve into just one scenario, and the observer affects the result. Now that's based on extremely small scale particle observation, but reality is made off small particles. So I agree with what's said in this vid that events are already "written" in relation to a specific timeline, but as a being who experience reality from a specific angle, in space time, it's only one temporary perspective. Cause and effect works, but it works like as if you were standing on a branch of a tree which hypothetically has an infinite height. When you work your way upwards (how you experience time right now), all paths are already there based on the principles of cause and effect, but you have a choice. Just my opinion, I'm no expert.
So this guy is saying that thing are meant to be ? Im bound to marry someone specific ? And i have no control to Change these events ?
Romanov 1917 "This guy (donno which guy you referring)" is saying that things are bound to happen in certain ways, and people have certain influence in choosing which one happens. Like when you are at a crossroad, you have the free will to take which ever road available, but you can't just fly up if that's what you want. Whatever is happening is bound by causality. And causality is not like a simple A => B, but A => perhaps infinite amount of results. It's all about possibilities.
the universe is actually a giant subwoofer!
Zetoto I disagree with that. In spacetime, our lives are line segments, as pointed out in the video. Our future is absolutely, 100% fixed, just like our past. The universe works the same in both directions, it's just that we humans can only look in one direction, and that's backwards. We can't look forward, into the future, and that's what creates the illusion of time "passing". But I don't get why people think this destroys free will. Just because you have already made your future decisions, they're still YOUR decisions. You made them with your conscious mind. Your timeline is fixed, yes, but you're still the one who fixed it that way.Make this life good, because despite our intuition, we never get to leave. We're all stuck on loop.
Everybody wants an answer, something to hold on to and sience is the ultimate expression of that. I love this video, because of relativity/personality, there is no answer. So instead of asking what is, or who is, right/true; everybody/everything is.
is anyone getting a headache from not understanding this?
+Michael Hutchinson I feel I getting a hunch, but not more - before my brain turns into SpaceJam every Time I watch such things. Sometimes I find connections, understand a bit more - and then start all vids over again I can find. Since years......
+Michael Hutchinson look up the Hutchinson Effect.
+Michael Hutchinson right beside you bro :p
***** Well, then do it better - I look forward to it.
meee
Thank you for helping me to begin to understand a subject that has long perplexed me! (from a great grandson of Hermann Minkowski)
Yes time is human emotion.
Coming back to this video after 1 year, i happy to say i can understand him better now 😀