Go to brilliant.org/nutshell/ to dive deeper into these topics and more with a free 30-day trial + 20% off the premium subscription! This video was sponsored by Brilliant. Thanks a lot for the support!
To Claim Their Bones ⚔ 50 (45+5) Atk Weight ⯀ Amt. x0 [Before Attack] For every 7 Poise on self, Atk Weight +1 (Max +2) [On Use] Until this Skill ends, this unit cannot be Staggered from taking damage [On Use] Deal +2% damage on Critical Hit for every 💨Poise Potency on self (Max 50%) +30% Damage on Critical Hit Deal +0.5% more damage for every 1% missing HP on self (Max 25%) If this Skill targets only a single enemy, deal +100% more damage (In Focused Encounters, a single Part) (IV) [On Hit] Inflict 3 🩸Bleed [On Hit] Inflict 5 ⚡Paralyze next turn
sorry, nope your life time stay the same, but it is just people outside your ship go older faster than you, but time for you stay the same than if you stay on earth, so one year stay one year for you the only nice thing it is instead to take 4 years to go to alpha centauri you can shorter that to few months if you move at 99% light speed
If you run faster you ll see more images, or info or feelings etc. But if you run slow you live the moment with continuum causality not virtual. People interacting with numbers or words need speed cause connectability or inspiration, even memory is connected through present time and through the work of multiple people. But it is another thing working for a living or sharing with others experiences and other thing to experience it from within. Eventually we ll find a way so that both will function at the same time..
As a physicist, I appreciate that the idea that this is an oversimplification is being made clear to avoid the maths. That said, I do have to make one "um acktchually". 5:54 Moving faster than light doesn't NECESSARILY mean you're moving back in time. What it does mean is that you're moving forwards in time in some reference frames, backwards in time in others, and are "stationary in time" in yet others. It's exactly the same as how moving slower than light means you can be moving forwards (in space) in some reference frames, backwards in others, and are stationary in space in yet others.
This sounds like what is theorised to happen "inside" black holes. Time and space "switch" places. You can move freely in time, but are fixed in one sapce dimension, towards the singularity. I think either PBS Spacetime had a video on this.
As a layman, if we are moving faster than the speed of light and thus moving backwards in time to the basic Earth reference frame, in order for us to appear to still be moving forward in time wouldn't that frame of reference have to be moving even faster than us? Or is it just a matter of perspective?
I have a similar grievance with the concept. Instead of viewing the spacetime vector space and summing vectors, and instead taking the actual Lorentz transformations, you’ll see that the gamma factor γ=(1-β^2)^(-1/2) becomes complex when v>c. In other words, faster than light speed wouldn’t imply going backwards in time, it means you’d be experience IMAGINARY time relative to the outside observer. What the heck does imaginary time mean? I don’t know. Maybe that’s one reason why superluminal things don’t exist (as far as we know).
Im a schizophrenic. I do doordash for extra money. One order at night, i arrived and walked to the door, placed his food down and took a picture. I got in my car and drove away. 30 minutes later he called and asked where his food was, i totally remember taking the picture at his doorstep. So he took it up with Doordash. An order later, i opened my back door and.. saw his order. I was so confused why it was there. I remembered everything about going there and taking the picture. Appearantly i hallucinated the whole delivery. I was there, but must of never left the car. What was i doing then?? Staring blankly at the windshield? He said I was never even on his camera.. I called him and apologized but he already got his refund. I felt so terrible. Im on medication and nothing works. It just goes to show how easily some misfirings in the brain can completely alter your sense of reality.
Don't feel bad about it, everyone lives in their own subjective realities anyway. Anyone can see something the same but understand it different and vice a versa. I hope you also get help with that though.
@@epimetheus8243 Nah, man. This is just one person sharing their subjective experience of our perceived reality… to see that as disrespectful towards a Kurtzgesagt video is pretty goofy - also, kind of hilarious.
@@TheSubwizzle Fair enough. I guess I missed that point and somehow overlooked his last sentence. My bad. I still think the story has nothing to do with the topic in the video. Yes, in both cases we speak of subjective perception, but in one case it's objectively measurable and a physically predictable property and in the other case it's psychologically induced and not compatible with objective external reality.
It is just like that except the former you can never get there and the latter you have arrived but cannot leave. No wait, not just like that. Hey at least you know an Eagles' song.
1:30 I had this concept of moving slower through time and faster through space explained to me multiple times in physics and this explanation just made way more sense than anyone else’s.
"Your speed is constant. So the faster you move thtough the space dimensions, the slower you mpve through the time dimension, and vice versa." Thats a very good descriptionnof time and space dilation!
Well with the dawn of the internet happening 20-30 years ago, a lot of the stuff going on today will probably be quite interesting to generations in hundreds/thousands/millions of years. Maybe not so much today, since there's just so much data being uploaded to the servers around the world and it's less interesting because it's been a few decades since the beginning of the internet, but around 1995 to 2010 were really the formative years of the internet. A lot of that stuff will probably be lost to time, but some stuff will be rediscovered over and over again I imagine. Things like vlogs, day in my life videos, etc. Compared to 50 years ago where we really only have movies and TV to show what life was like. Or 500 years ago where we only have books documenting what life was like.
@@annaoldfield2298It's much more likely we will find a way to stop natural aging before we discover time travel. So you may still be around in 100 years.
In all the years listening to these theories on UA-cam, ive never heard any other UA-camr explain the "4 dimensions, 1 speed of light" limitation the way you did, and accurate or not, it's a darn good way to remember and understand this concept. Thank you for this video!
@@ciCCapROSTi I haven't heard of the combination of time and space being always at the speed of light and have degrees to prove that I've looked hard enough.
One possible reason that we've never actually found any tachyons is because, arguably, it's probably impossible to tell the difference between an elementary particle travelling forwards in time from A to B in space vs a particle travelling backwards in time from B to A. Therefore, potentially, _every_ regular particle in the universe (except photons) is also a tachyon at the same time, if you just look at it from the other direction.
It's just that: How can you measure an object moving backward in time if you're limited to moving forward in time? Either that or I've drunk too much vodka...
"vs charge-inverted, parity-inverted particle" travelling backwards in time, but seems to be legit, yes. Also: what use to us are those tachyons? When we get in the future to "send the message" it's too late to, anyway =)
This absolutely broke my brain and gave me chills, this could be a horror movie by Steven king where someone goes faster than the speed of light but can never return and is imprisoned forever
I really like the back and forth between the story and the physics! "Heres the simpler version, and why it works in theory... but it doesn't work like that in reality for more complex reasons."
The simple fact, that time travel would create paradoxes proves time travel to be impossible. The universe does not deal with paradoxes. We havn't found a single one yet, so we can assume there are none. If there are none, there never will be one. If there never be one, time travel is therefore impossible. Not the best induction, but it gets the point across.
3:30 While you could call this a paradox, this is not the full *Twin Paradox.* The Twin Paradox is a problem that arises when you tackle this scenario using special relativity (absence of consideration of gravity and acceleration). Since movement is relative, each twin sees the other move away near the speed of light, then come back. This means that both twins see the other's time as moving slower (since time will always move slowly for anyone moving fast relative to you, and each twin sees the other as moving fast relative to themselves). The Twin Paradox results from the fact that if you follow the twin on earth special relativity says the twin that travelled in the rocket must have aged less, and if you follow the twin on the rocket special relativity says the twin on earth must have aged less. So we've concluded two contradictory pieces of information - that both twins must have aged less than the other. The solution to this comes from general relativity. At some point on their journey, the twin on the rocket must accelerate towards earth in order to come back. During this acceleration time will pass rapidly on earth from their perspective (how strong this effect is depends on the distance from earth they are during their acceleration), making the Earth twin older when they return. Edit: Some have noted that this can be resolved without general relativity or acceleration. If someone can provide a simple description of how this works I may add it to this comment. Others have noted the acceleration in this case does not require general relativity to be described. This seems to be correct, and I apologise. It remains that the paradox arises from failure to take into account the fact that one twin must turn around, and therefore does not remain in a single inertial (constant velocity) reference frame for their entire trip.
@GATCornebre non inertial reference frames are not relative in this way. That is if you are accelerating relative to something then the physics varies depending on which one you use.
@@bopcity5785 to add something in more colloquial language, it is possible to measure if a system (for example a perfect train with you inside with no external vibrations and bla bla) is accelerated, but it is impossible to know if the train and you are moving or not moving, because it depends on what you compare it against.
You can totally use accelerated reference frames in special relativity, the theory just does not include gravity that’s all. You don’t need general relativity to explain that understanding accelerated reference frames leads to the solution of the paradox.
Question: If one of the hypothetical twins is traveling in a spaceship with a speed close to the speed of light, the other one staying on Earth is also traveling with the same speed relatively to the first one. Why do we assume only the second one would age? Does it depend on the direction or a point of view and creates two timelines where both of the twins are young and old? So basically: timetravel
I love Tachyons for the go-to technobabble when time travel shenanigans occurs in Star Trek. "Why are we colliding with our future selfs, Data?" "Tachyons sir."
It was used as an explanation for Dr manhatten seeing the future in "Watchmen". The tachyons he produces get sent back in time to his past self so he essentially receives constant data from his future self 😂
@@FreakyDickyCrafteryou mean the story about a guy who experiences apotheosis after being electrocuted really hard and becomes literally omnipotent actually ISNT realistic? I'm shocked.
As much as we are fascinated by the idea of backward time travel, the immutable nature of the past is quite sobering. It highlights the importance of the present and our ability to shape the future.
@@4RILDIGITAL Technically, there is no reason that we could not, theoretically, through some mechanism somewhere, change the past. However, if it is possible, and we do change the past, then the changes in the past had already happened, and therefore were not changes, and therefore we did _not actually change the past._ Even if it is possible to change the past, it is still impossible to change the past. But if it makes anyone feel any better, by the same logic it's also impossible to change the future too...
@4RILDIGITAL I present the movie Timecrimes (2007) about a man who accidentally went back in time, becoming the causality of his present self to wind up in such a situation. [Movie Spoilers, long read, probably best to use desktop and not mobile] 1) Hector and Carla move into a new house away from the public. Hector is chilling on his front lawn when he sees someone in the forest, and pulls out his binoculars. A naked lady. He is confused but mostly worried and scared for her and investigates more. 2) Hector eventually catches up to her to see her unconscious near a rock. A man with a bandaged head starts chasing after him. 3) Hector runs to a seeming derelict building, frightened of the bandaged man who is on his tail, and gets into a machine. 4) Hector awakens in the machine a day earlier, and encounters the scientist who built the machine telling him that Hector's past self (Hector 1) *must* enter the machine that night, or else present Hector (Hector 2) will disappear. 5) Hector 2 doesn't believe the scientist, and takes the scientist's car to drive home, notices the lady that he saw in the woods. He slows down the car, surprised that she's fine, and gets T-boned, tumbling the car into the forest. He bandages his head. 6) The lady hears this and goes to help. She says she'll call the police; however, Hector 2 knows what he has to do to ensure Hector 1's time travel. 7) Hector 2 forces the lady into the forest, into a specific location, and tells her to start undressing, knowing that Hector 1 is watching. 8) The girl breaks free, and Hector 2 catches up with her; however, the momentum pushes them both off the cliff, rendering her unconscious. Hector 2 finishes the setup by putting her near the rock. 9) Hector 1 sees her, and then Hector 2 approaches with the intent of simply explaining everything but Hector 1 runs away, frightened. Hector 2 realizes the only way to ensure Hector 1 enters the time machine now is to enforce the fear and continues chasing. 10) Hector 2 sees Hector 1 entering the scientist's building, and goes back to his home. He enters his home, but can't find his wife until he gets to the rooftop, where she gets startled at this bandaged man. His wife falls off the roof. He looks over the edge and sees her dead on the backyard. 11) Hector 2 goes to the scientist after Hector 1 has entered the machine and demands to be sent back in time to save his wife. 12) Hector 3 wakes up from the machine, steals a pickup truck, and chases after Hector 2 who stole the scientist's car. 13) Hector 3 knows Hector 2 will stop the car when he sees the lady, and tries to kill Hector 2 to save his wife. Hector 3 rams into Hector 2's car, tumbling it into the forest. He falls unconscious. 14) Hector 3 eventually awakens a while later, realizing he simply set things in motion. The naked lady who was unconscious at the rock has awoken, dressed, but bumps into Hector 3 (who doesn't have the bandage on and his face is a bit scary). She gets frightened but she doesn't recognize him. 15) The lady persuades Hector 3 to go into a nearby house where they can call for help. She doesn't realize this is Hector's house. 16) He stays in the kitchen and she goes upstairs. His wife enters the house. Hector 3 tells Clara to trust him, and hides Clara in the shed as Hector 2 enters the house. 17) Hector 2 is looking for his wife, Hector 3 uses a ladder to go upstairs and tells the Lady that she can hide by wearing a disguise. 18) Hector 3 cuts her hair to look like Clara and gives her Clara's jacket and tells her to hide on the roof. 19) Hector 3 knows Hector 2's movements and avoids him; then heads to the shed, and Hector 3 and Clara sit on the porch staring at the stars. 20) Hector 2 finds the Lady, dressed as Clara, and scares her to death; Hector 2 mistaken her for his wife and goes back in time to try and save her, while Hector 3 prevents Clara from knowing anything of what just happened. To me, this is one of the best telling of Time Travel. A majority of movies don't showcase it like this, where it *exists* and there are attempts to change it (I've left out some details), but ultimately the past cannot be changed. Time is immutable. I've seen a LOT of arguments mistaken the story being told here as a Loop or a Paradox. It's not either. No one is stuck infinitum. Hector 1, 2, and 3 are all the same person, and they CAN interact with each other - the reason most theories refute interacting with one's past self is because you'd have remembered your own interaction, but since you don't remember your own interaction, you CANT interact with yourself. Which is true, but this is the other side of that coin. Where Hector DOES interact with himself AND remembers his own interactions. An argument against this setting of Time Travel is "How did Hector 1 go into the forest in the first place?" - folks are committed to the idea that Hector 2 doesn't exist yet. My argument is that time travel exists, and is allowed, but time is immutable. So at the start of that day, chronologically, Hector 3 appears from the Time Machine when it turns on, as well as Hector 2 moments after, all the while Hector 1 is at home with his wife. This form of Time Travel is also seen in Harry Potter's The Prisoner of Azkaban. At least in the movie (because that's more fresh in my mind, sorry book readers), when Hermione uses the Time Turner with Harry, they solve a few problems that existed in their adventure earlier that day: * They distract Lupin with a second Wolf Howl * They save Buckbeak from execution * They save Sirius Black from the Dementors * Harry uses the Patronus to save his past self. These moments indirectly interacted with their present selves. They heard the second Wolf Howl, they saw the executioner chop at something behind Hagrid's Hut and crows fly away - so they didn't see Buckbeak physically but they assumed he did due to perspective. Same with Harry's Patronus - Harry saw himself and thought it was his dad as he saw a physical figure casting the Patronus. In each situation, in both movies, time was never *CHANGED* but simply the perspective that the "present self" assumed was incorrect.
@@foogod4237I mean, if they do time travel like Avengers endgame then maybe not, but if we use the widely accepted version of time travel then you are right yes
@@coypandora0795 To be fair, I just like speculating on this, but I feel like basically it would be a hybrid of 'immutable time' with the idea of the Many-Worlds theory (in that every possibility does happen, and every possibility is a branch of our universe that we perceive - therefore back-travel could be considered as going back to a 'fork in the road' so to say) as well as the idea that well, you can technically reproduce/go back to the original timeline by handling something in the future with a past-gotten tool, then going back to the same point where you got said and revert that change, effectively trying to "limit" the amount of change that actually occurs in the past (closing any 'forks' you traveled/caused) while having a (user-perceived) positive effect on the future.
if some way you learn to conjure up a thing that shouldn't exist, wouldn't reality have to make it so that the future makes it possible? eg. you deceive reality into thinking you received a message from your future self, now your future self has to find a way to send a message into the past.
I’ve always thought this logic is absolutely fascinating because it confirms that it’s impossible for time to be finite while space is infinite. Put it this way, if area is infinite then you should of course be able to travel in any direction infinitely, but it also means that you would be able to upscale/downscale infinitely as well, leading to fascinating repetitions of life on multiple scales. For example; look at your hand, if space is infinite then look at any part of ur hand and in the unfathomably small sub-atomic scale there is a certain reputation of yourself, a ‘clone’ identical to you in the molecular scale doing the exact same thing in the exact same scenario and universal composition. However where I’m getting at with the time thing is: if area=infinite, then infinite upscaling=true, hence the identical, composition of you right now is for certain everywhere on the molecular and gargantuan scale, and if time is relative to speed then the sub-atomic ‘you’ will be dead in a blip, whereas as the gargantuan ‘you’ would still be looking at there hand far past your death because the relative movements of each ‘you’ is drastically different: e.g gargantuan ‘you’ where your universe only makes up a fraction of an atom for their universe would be moving an unfathomable speeds relative to us because of the unbelievable difference in size, tiny you would already be dead. And because area=infinite in the scenario, no matter how small you go to get to that tiny ‘you’ looking at there hand, there’s an even tinier ‘you’ on their hand and so on, all experiencing time slower and slower, and slower, and slower. Meaning time relative to infinite area is inevitably infinite, even if it’s not. lol (obviously idk what I’m talking about, just a cool concept I had when watching the video)
This video helped me realize how incredible photos and videos are, the fact that we capture a piece of the past and are able to replay a moment in time which usually could never be reached again.
If tachyons travel backward in time, then from our perspective, wouldn't they appear to be issuing from whatever point they are ending their journey and seem to be absorbed by whatever is creating them?
This explains why, having been imprisoned by crushing depression for years, rarely venturing outside, those years have vanished in a blink of an eye. Slow in space, fast in time.
isn't it the opposite? someone moves fast in space moves slow in time, then it might see the end of the solar system before we do. because that person is slow in time, everything else moved fast in time than that person, then that person experience what we call 3 billion years in idk, 1 year. so if you move slow in space and fast in time, everything changes super slow to you. then you would experience everything changing super slowly. therefore the suffering of depression feels like eternity.
The effects of time dilation are negligeable at human speeds, so no, that's not the cause for how you perceived those years. Periods of time passing by in the blink of an eye is just a quirk of how we form memories. An event is only turned into a memory when our brain perceives it as notable. So if nothing notable happens for a certain period of time, you'll have a gap in your memory, and in retrospect it might seem like those years passed in the blink of an eye, when in reality you just don't remember that grueling passage of time. Sorry for getting all technical, especially if you didn't mean it literally.
heck yeah, fellow depressionist, here. Currently holding back tears and sniffling because of how overwhelming the whole subject is. Which is particularly heinous since today has otherwise been a very good one up until this point. THANKS KERKSKIZAGHTTHT!!!
Relatable. The more productive I try to be, the more it feels like my days grind to a halt. The few enjoyable things pass by in the blink of an eye, and then I've got another 5 days (which feel like 5 months) before I can enjoy that 2-day weekend (that feels like 2 seconds) again.
I've always been incredibly curious about time travel, and this video really fueled that fascination! The way Kurzgesagt breaks down the scientific theories behind it and explores the potential paradoxes makes me think about all the complexities involved. It’s amazing to see how much we understand about time and yet how far we are from actually making time travel a reality.
8:45 yes! I teach this to my clients... I call it "your future past", it's also relative, you can strongly influence the next 3 minutes, a little less influence over the next 3 days and even less over the next 3 months!
just gotta say i love all the nintendo character references hidden in the background of these videos. i found 2 in this one 2:51 olimar from pikmin 3:56 kirby and bandanna waddle dee
you have forgotten to mention another important reason why time travel to the past is difficult: in order for past events to be accessible to a time traveler, those events have to have been recorded or saved in some kind of universe-memory. Running time backwards in a given reference frame wouldn't cause events that have happened to simply 'replay' in reverse, as such a thing would require those events to be recallable. Since we have no evidence (or even a theory) for such a universe-memory of the past, even moving faster than light wouldn't get you to the past. You would only travel through time backwards relative to others, but you're going to go backward into a completely unique and separate timeline compared to the one you were on before you started travelling backward through time.
gravity anchors every observer to the same timeline. what you're positing is pure speculation. granted, mine is as well, but mine makes more sense than yours
Altough this would solve all of the past-time-travel paradoxes, since if traveling into the past makes you travel into a unique 'past' timeline, you're interactions with said unique timeline could not disturb the one in which you traveled through time to the past. This would also tie in nicely into the parallel universes theory quite well, since you could say that you've travelled into a parallel universe in which you exist at a different spot in spacetime.
I have watched quite a few videos where they explain time dilation (which I fully understand) but hands down, your explanation was orders of magnitude easier to understand and visualize! Bravo!! Oh and maybe a video on the hypothetical “Jinn” particle which puts a bandaid on paradoxes would be a fun one. You have gained a subscriber nonetheless 😎
7:19 It's theorized that the opposite is true for superluminal objects. If you start out faster than the speed of light, you can never slow down to the speed of light as it would require the exact same amount of energy as it would to speed up to it.
@@MrEpicfull I'm not sure about comics Savitar, as while I do enjoy superhero fiction, I have never been a comics guy. Ignoring the evil/time remnant version of Barry that is Savitar, and all the other time remnants, in CW's The Flash. _ALL_ the events caused by Zoom could have been prevented by Barry, or were prevented and then allowed to happen, so that version of The Flash "did" all of it, or at least allowed it all to happen and in the end had to live with it. That said, I was just subverting the meme with a time-travel joke.
I am a secondary school biology teacher. I sat in my classroom during my free period this morning and overhead this exact lesson by the physics teacher next door. I guess I'll never forget it now lol.
6:33 "But now for the first time, some observers could actually see tachyons literally traveling backwards in time" I instantly paused the video and googled it expecting to find research articles but realized I've been tricked, backstabbed, and quite possibly, bamboozled. I know you said you're a liar, but c'monnn💀
the context was that you can see the tachyons if you reach the speed of light. no doubt you are a fast runner but I'm pretty sure you didn't reach the speed of light to see the tachyons
If time dilation is explained by a simple arithmatic problem consisting of the addition of two simple variables, how come it took me multiple years to find that out?
"Have you seen Isaac Newton with a lead pipe waiting outside a house, looking like he is going to reduce the head of whomever lives in the house into apple paste?"
Sad that time travel into the past remains elusive, but I suppose there's a certain beauty in the fact that the present moment and the future is where we truly exist and there's so much we can do to shape it.
Its elusive because there literally is no past. The universe moves through time same as you. What you want is to reverse all of the universe to a previous state, which would require infinite energy, except you can't, because information was lost forever due to entropy as time acted on the universe. It's like coming upon a pile of ash, pure carbon. What was burned to make that ash? You don't know. You can't know. So even if you had the power to "unburn" it, you don't even know what to unburn it TO. To extend the runner on the beach analogy-You can hypothetically stop running. Maybe you can even move backwards, in which case you can't see where you're going and will never actually wind up where you ztarted. But the other runner keeps going. You can't convince him to return to the starting line. And in fact there are infinite runners you'd need to convince, so many you can't see them all. You can't restart the race.
That's not implied at all. The past isn't any less real than the present or future. Physics doesn't point at presentism at all. To the contrary, relativity strongly implies eternalism.
@@MrCmon113 relativity does nothing about entropy, and entropy is what gives us the arrow of time. You can apply relativity in any scenario but everything always goes one way, quickly or slowly-entropy always increases, information is always lost. The past is only real as an abstract concept. It's not some place to visit, except in your fading memories.
Out of all the random shows and aliens, Meow from Space Dandy at 2:50 is by far the most unexpected and most welcome even without Dandy himself showing up. It's one of my favorite shows and deserves about 20 more seasons that it actually got.
Let ask you this If time travel is created or exists Wouldn't people from the fiture or pesent or past whatever visit out timeline? Or did it or will it happen already?
3:27 Is there a smaller scale version of this that could be used to test this theory? Like, say you get two very similar bananas, for example, and you take one and put it in something that spins extremely fast so that it is constantly moving at a fast speed and then leave the other banana sitting out to get old, and then after like a few days you take the banana out of the spinny thing and compare it to the other banana and see if there is a difference in how they aged?
In the case of space-time it's τ^2 = t^2 - x^2, not "+". Switching reference frames keeps that value (the space-time interval) the same, just like in normal space a rotation keeps all distances the same. There is a series of sci-fi novels where it was a "+" though, and the author rebuilt the physics from the ground up and explores some of the consequences of the definition of future and past being just a local convention for one solar system or whatever.
@@SimonClarkstonedo you remebrt the name of that, i heard of another sinilar one with a universe with 2 time dimensions and cant remeber its name, that one you talked about sounds similar
@@SimonClarkstone Yeah so actually the faster you move through space the faster you move through time.. The video's explanation of time dilation is just fundamentally wrong. Ultimately it's because there's no 'fast' or 'slow', it's all relative.
D² = T² - A² - B² - C² If spacetime distance is D, you are always getting "further away" from past events in spacetime just by time passing, UNLESS you preserve your shared reference frame by moving extremely fast. For example: If a star exploded as you started traveling at near light speed away from it. You'd continue to stay in that same moment with it. You'd go far without experiencing any passage of time... For your entire journey, the supernova will have only just exploded. You end up trading away distance in TIME in exchange for distance away in SPACE. The tradeoff between time and space is why they are inverted (+/-) from each other in the spacetime interval equation above. If D² > 0, time is the dominant factor in measuring the distance to an event. (Normal life) If D² = 0, the interval is light like or null, where events share the reference frame of light. (Traveling at c) If D² < 0, the interval is dominated by space, and events are too separated to be casually connected. (Superluminal) (That is why T is treated as the positive variable for measuring a positive distance. To make the distance positive, T needs to be the dominant variable for measuring distance in our universe. Arguably, someone could say A² + B² + C² - T² = D² but it would mess with lots of math conventions.) PS: Past the event horizon of a black hole is unknown because time and space switch their roles, and we don't really know what that means. In the math, the variables switch dominance. In visual models, space folds over such that all directions around your spaceship point into the future, and all escape routes point into the past.
I've never subscribed to the idea that time is the 4th dimension, because it simply diverges far too much from the rules of the first 3 dimensions. Note that this isn't to say I disagree with any of the information presented here on the functionality or flow of time, but rather that I disagree with specifically labeling time as a dimension, if we're to assume length, width, and depth/height are what we're considering to be the other known dimensions. I can't help but think back to Edwin A. Abbott's "Flatland: A Romance of Many Dimensions," and beyond that to "Sphereland," a sequel to Flatland written by Dionys Burger around 80 years later. In Sphereland, there's a simple thought experiment presented that helped me visualize a 4th dimension for the first time in my life, and I've never been able to get it out of my head. Basically, say you have a sheet of paper, and you "flip" it through the 2nd dimension. This basically means rotating it on the tabletop -- what's displayed on what we'll call the "frontside" will always be on the frontside, and what's facing the table will always be the backside. Flip that sheet of paper through the 3rd dimension, however, and suddenly, the frontside of the paper is facing down, into the table, while the backside of the paper is facing up. Now let's change to a more complex object: a shoe. Specifically, a left shoe. No matter how you flip a left shoe in 3-dimensional space, it will always be a left shoe... but if you could flip it through 4th-dimensional space, you could make that left shoe into a right shoe. Think about that for a moment: being able to flip something through space in such a manner that you essentially mirror it. That's the 4th dimension -- that's the next dimension after length, width, and depth/height. When considered in that manner, the idea that time is the 4th dimension starts to seem a lot more... absurd. You certainly can't "flip" a left shoe through time and make it into a right shoe in an instant! My conclusion, therefore, is that time is not a dimension. It is a separate... entity... altogether. It does not behave as a dimension behaves, but rather moves to the beat of its own drum, and should therefore be regarded as something altogether different from length, width, and depth/height. In short, time is time, and it should be regarded as such. Presuming it to function as a dimension can only serve to limit our ability to understand it, as we will be operating under misguided preconceptions. We must open our minds not just to the possibility, but to the probability -- nay, the veritable certainty -- that time is an altogether separate concept from dimensionality.
If a bomb explodes and you are moving faster than light, you might 'see' the bomb unexplode but just because you are moving fast - the bomb exploding has happened, you can't reverse the universe by moving faster than it - you just start reverse-seeing
Believe me if you are tuned in a higher state withing your self(not drugs but clarity of thought) and spirit you can even feel the void just before a lightening strikes. And much more, like predicting goals in matches, weather forecasts, even prophecies in the deeper dimention of time. And it is not reverse seeing. It's like self and double mirrors. Self is the body, first mirror the observer of what you are (doing), second mirror the matrix of reality. Internet and social media are the simulation(mirror of the body itself) that aliens use to train us on how to create reality not machines😂 Some other aliens have fell in the trap and believed the internet is real, and they sleep with their phone in the side of their pillow. What can you say about those poor slaves😂
But if you are travelling faster than the photons required to see the event wouldn't you only be able to experience it if you're moving toward where they are coming from in space (the explosion)? Or, since you could theoretically catch up to them, moving away from the explosion at those speeds would mean catching up to photons that had already passed and seeing a slow motion reverse image?
Oh this makes sense to me. It's like being able to travel faraway, and seeing the radio signals of the past. Just because you can see those transmissions doesn't mean you're actually there. Furthermore, in order to keep "being there", you need constantly be travelling to keep up with the radio waves as they go. You can't physically interact with anything, so, it's kind of useless.
Go to brilliant.org/nutshell/ to dive deeper into these topics and more with a free 30-day trial + 20% off the premium subscription! This video was sponsored by Brilliant.
Thanks a lot for the support!
hi
To Claim Their Bones
⚔ 50 (45+5) Atk Weight ⯀
Amt. x0
[Before Attack] For every 7 Poise on self, Atk Weight +1 (Max +2)
[On Use] Until this Skill ends, this unit cannot be Staggered from taking damage
[On Use] Deal +2% damage on Critical Hit for every 💨Poise Potency on self (Max 50%)
+30% Damage on Critical Hit
Deal +0.5% more damage for every 1% missing HP on self (Max 25%)
If this Skill targets only a single enemy, deal +100% more damage (In Focused Encounters, a single Part)
(IV) [On Hit] Inflict 3 🩸Bleed
[On Hit] Inflict 5 ⚡Paralyze next turn
@AUTTP-i2n good bot
AY YO ! @Geopoldd
Dont like this comment
"One beer for me please" he says
A Tachyon walks into a bar
ha
He gets out of the car.
He drives for fifteen minutes.
A Tachyon got into the car after a long day of work.
Hohoho!!!
What a kneeslapper!!!
Why is this joke so good
Superluminal Tachyon!
Super who?
Super.
Who's there?
Knock knock.
What this video taught me is that speeding makes you live longer
Not really. Just from the perspective of others.
Did I get that right?
I have a headache.
Yet on average, speeding makes everyone's lives shorter.
sorry, nope your life time stay the same, but it is just people outside your ship go older faster than you, but time for you stay the same than if you stay on earth, so one year stay one year for you
the only nice thing it is instead to take 4 years to go to alpha centauri you can shorter that to few months if you move at 99% light speed
Then Ricky Bobby is the oldest human on earth.
If you run faster you ll see more images, or info or feelings etc. But if you run slow you live the moment with continuum causality not virtual. People interacting with numbers or words need speed cause connectability or inspiration, even memory is connected through present time and through the work of multiple people. But it is another thing working for a living or sharing with others experiences and other thing to experience it from within. Eventually we ll find a way so that both will function at the same time..
"shaping the future is much easier than changing the past " is kind of motivational
This video was kinda pointless
It's also a damb lie
@MaxCornerstonethecool damn + dumb = DAMB!
@MaxCornerstonethecoolnah ‘b’ and ‘n’ are right next to each other 😂
I fell asleep while watching this, and literally time traveled to the future!
"We're twins!"
"Really? You guys don't look the same age."
"It's complicated."
"But perhaps not as complicated as you may think. 🦆"
- Kurzgesagt probably
@@famcamp3414"no"-Abraham Lincoln
@@famcamp3414 "Or is it?"
- Vsauce
"one of us went to space"
As a physicist, I appreciate that the idea that this is an oversimplification is being made clear to avoid the maths. That said, I do have to make one "um acktchually".
5:54 Moving faster than light doesn't NECESSARILY mean you're moving back in time. What it does mean is that you're moving forwards in time in some reference frames, backwards in time in others, and are "stationary in time" in yet others. It's exactly the same as how moving slower than light means you can be moving forwards (in space) in some reference frames, backwards in others, and are stationary in space in yet others.
This sounds like what is theorised to happen "inside" black holes. Time and space "switch" places. You can move freely in time, but are fixed in one sapce dimension, towards the singularity.
I think either PBS Spacetime had a video on this.
@@NineSun001ScienceClic English has an AWESOME video about this ❤
So the faster you move the more time you have?
As a layman, if we are moving faster than the speed of light and thus moving backwards in time to the basic Earth reference frame, in order for us to appear to still be moving forward in time wouldn't that frame of reference have to be moving even faster than us? Or is it just a matter of perspective?
I have a similar grievance with the concept. Instead of viewing the spacetime vector space and summing vectors, and instead taking the actual Lorentz transformations, you’ll see that the gamma factor γ=(1-β^2)^(-1/2) becomes complex when v>c. In other words, faster than light speed wouldn’t imply going backwards in time, it means you’d be experience IMAGINARY time relative to the outside observer.
What the heck does imaginary time mean? I don’t know. Maybe that’s one reason why superluminal things don’t exist (as far as we know).
Excellent video. Will have to watch it again yesterday, since I've already seen it tomorrow.
Source?
@@AUTTP-b8lit was you!!
Except it’s entirely wrong
@@PerpendicularFlight5in the future 😏
You cannot have seen it tomorrow because that violates causality and is a logically pernicious self-inhibitor.
Everyone commenting on this video already must have time travelled to finish it.
exactly
Damn it, you caught me
Who is here from india 🇮🇳
Straight up
Haha 😂😂😂😂
Im a schizophrenic. I do doordash for extra money. One order at night, i arrived and walked to the door, placed his food down and took a picture. I got in my car and drove away. 30 minutes later he called and asked where his food was, i totally remember taking the picture at his doorstep. So he took it up with Doordash. An order later, i opened my back door and.. saw his order. I was so confused why it was there. I remembered everything about going there and taking the picture. Appearantly i hallucinated the whole delivery. I was there, but must of never left the car. What was i doing then?? Staring blankly at the windshield?
He said I was never even on his camera..
I called him and apologized but he already got his refund. I felt so terrible. Im on medication and nothing works. It just goes to show how easily some misfirings in the brain can completely alter your sense of reality.
Don't feel bad about it, everyone lives in their own subjective realities anyway. Anyone can see something the same but understand it different and vice a versa. I hope you also get help with that though.
You might be hallucinating again, thinking that your story would be appropriate under this video. It just feels disrespectful.
@@epimetheus8243 Nah, man. This is just one person sharing their subjective experience of our perceived reality… to see that as disrespectful towards a Kurtzgesagt video is pretty goofy - also, kind of hilarious.
@@TheSubwizzle Fair enough. I guess I missed that point and somehow overlooked his last sentence. My bad.
I still think the story has nothing to do with the topic in the video. Yes, in both cases we speak of subjective perception, but in one case it's objectively measurable and a physically predictable property and in the other case it's psychologically induced and not compatible with objective external reality.
Maybe you were hungry?
The professors getting mad and breaking a ruler was so good. Made me smile.
What are they mad about?
So nostalgic
Yeah
e
very fun
The message saying "Run" to the twins from before is gold 😭
the lore
Could be a great movie
A FELLOW SEAL
I saw this comment before I saw that in the video
@clivah1499 the GLORIOUS lore
"You can get as close as you like, but you can never reach it" has the same vibes as
"You can check out any time you like, but you can never leave"
It is just like that except the former you can never get there and the latter you have arrived but cannot leave. No wait, not just like that. Hey at least you know an Eagles' song.
why do i hear a sick guitar solo?
Welcome to the
Welcome to the hotel California🗣️🗣️
@@robertandrews9856 It’s a lovely place
1:30 I had this concept of moving slower through time and faster through space explained to me multiple times in physics and this explanation just made way more sense than anyone else’s.
probably a good part due to the incredible and beautiful animations.
@ this is true. Visuals always help
Probably something to do with Kurzgesagt "simplifying, and lying a bit."
@@Cupcakening it's entirely possible
1:02 "Keep in mind that we're simplifying and lying a little".
I like that confidence.
Simplifying and lying is the only way to explain this easily.
That confidence is true.
0:01 "You're going through time 1 second, every second."
"Every 60 seconds in Africa, a minute passes."
Source?
Same vibe
Together, we can stop this.
@@PerpendicularFlight5just trust him bro
@@PerpendicularFlight5 he made it the fuck up
"Your speed is constant.
So the faster you move thtough the space dimensions, the slower you mpve through the time dimension, and vice versa."
Thats a very good descriptionnof time and space dilation!
The correct one too.
Space and time are strictly mathematical constructs and that’s why they can’t dilate or do anything else that physical objects can.
@@Jolly_Rodger ?
I've got a physics degree, and it's still the best description of time dilation I've heard (and not one I had heard before).
Like you could go back in time and tell yourself to hit the "r" instead of the "t" when you are spelling the word "through".
8:12 this part made me realise that in a few 100 or 1000 years we will be locked away to never see again if we don’t find a way to time travel
Well with the dawn of the internet happening 20-30 years ago, a lot of the stuff going on today will probably be quite interesting to generations in hundreds/thousands/millions of years.
Maybe not so much today, since there's just so much data being uploaded to the servers around the world and it's less interesting because it's been a few decades since the beginning of the internet, but around 1995 to 2010 were really the formative years of the internet. A lot of that stuff will probably be lost to time, but some stuff will be rediscovered over and over again I imagine.
Things like vlogs, day in my life videos, etc.
Compared to 50 years ago where we really only have movies and TV to show what life was like.
Or 500 years ago where we only have books documenting what life was like.
I guess it would
But hey only time can tell lol
@@annaoldfield2298It's much more likely we will find a way to stop natural aging before we discover time travel. So you may still be around in 100 years.
In all the years listening to these theories on UA-cam, ive never heard any other UA-camr explain the "4 dimensions, 1 speed of light" limitation the way you did, and accurate or not, it's a darn good way to remember and understand this concept. Thank you for this video!
Well then you haven't seen scienceClick English , he's amazing at explaining it visually. Years before kurz gesagt did
You haven't been looking hard then. This is kinda basic.
@@ciCCapROSTido you enjoy condescending people on the internet for learning things?
@@kafkachampinHow is that condescending lol?
@@ciCCapROSTi I haven't heard of the combination of time and space being always at the speed of light and have degrees to prove that I've looked hard enough.
How are y'all pumping these videos out so fast? I remember back when I had to wait a good month for a new video.
Must have expanded their team
Tat
@Joseph44144 Stop, bot.
I am from 2015. one month one video.
I thought it was just me
"Yes I am."
"Are you a time traveler?"
Clever
**Sci-fi sound**
**Guy appears in the room**
"I did it! The machine works!"
I am suddenly not wanting to blink
".Ma I sey"
"?Rellevart emit a uoy era" xDxD
"I yes am"
"A time traveller you are Dagobah from?"
8:35 the big yellow ball and… reference was just legend there
Wow can't believe this video is already 10 years old. Feels just like this morning when I watched it for the first time!
Punching my ticket here so I can see this when it gets recommended 10 years later
You must be going fast
erm
Wow
Blud it’s 2024
3:39 "younger twin is ready to take years of therapy for being abducted by physicists" 😂😂 still cracks me up like it did when it came out 6 years ago!
You will turn up the dial too high, resulting in larger backwards temporal movement my friend.
You misquoted.
*theoretical physcicists
😂😂
@@Jordan-yb2ju and your a nerd
One possible reason that we've never actually found any tachyons is because, arguably, it's probably impossible to tell the difference between an elementary particle travelling forwards in time from A to B in space vs a particle travelling backwards in time from B to A. Therefore, potentially, _every_ regular particle in the universe (except photons) is also a tachyon at the same time, if you just look at it from the other direction.
It's just that: How can you measure an object moving backward in time if you're limited to moving forward in time? Either that or I've drunk too much vodka...
"vs charge-inverted, parity-inverted particle" travelling backwards in time, but seems to be legit, yes. Also: what use to us are those tachyons? When we get in the future to "send the message" it's too late to, anyway =)
even if theyre possible, is there a reason they should exist? like why do tachyons have to exist, where would they come from?
@@womp47 from the future, self-evidently? From the standpoint of relativity, future is already "past" in some sense anyway...
Just take some energy from them and see if they speed up
This absolutely broke my brain and gave me chills, this could be a horror movie by Steven king where someone goes faster than the speed of light but can never return and is imprisoned forever
I really like the back and forth between the story and the physics! "Heres the simpler version, and why it works in theory... but it doesn't work like that in reality for more complex reasons."
Thumbnail: "We Traveled Back in Time."
Video: "Time travel is not possible."
Universe: "Paradox!"
Trivago: Hotel
Bro why the tf are u mentioning trivago😂
Nerd
HAL9000: that's space Odyssey 2001 right
The simple fact, that time travel would create paradoxes proves time travel to be impossible. The universe does not deal with paradoxes. We havn't found a single one yet, so we can assume there are none. If there are none, there never will be one. If there never be one, time travel is therefore impossible.
Not the best induction, but it gets the point across.
3:30
While you could call this a paradox, this is not the full *Twin Paradox.*
The Twin Paradox is a problem that arises when you tackle this scenario using special relativity (absence of consideration of gravity and acceleration).
Since movement is relative, each twin sees the other move away near the speed of light, then come back. This means that both twins see the other's time as moving slower (since time will always move slowly for anyone moving fast relative to you, and each twin sees the other as moving fast relative to themselves).
The Twin Paradox results from the fact that if you follow the twin on earth special relativity says the twin that travelled in the rocket must have aged less, and if you follow the twin on the rocket special relativity says the twin on earth must have aged less. So we've concluded two contradictory pieces of information - that both twins must have aged less than the other.
The solution to this comes from general relativity. At some point on their journey, the twin on the rocket must accelerate towards earth in order to come back. During this acceleration time will pass rapidly on earth from their perspective (how strong this effect is depends on the distance from earth they are during their acceleration), making the Earth twin older when they return.
Edit: Some have noted that this can be resolved without general relativity or acceleration. If someone can provide a simple description of how this works I may add it to this comment.
Others have noted the acceleration in this case does not require general relativity to be described. This seems to be correct, and I apologise. It remains that the paradox arises from failure to take into account the fact that one twin must turn around, and therefore does not remain in a single inertial (constant velocity) reference frame for their entire trip.
But, if everything relative: Twin A accelerating towards Twin B could also be flipped around, no?
@@GATCornebre No, because acceleration (or gravity) is not relative like speed
@GATCornebre non inertial reference frames are not relative in this way. That is if you are accelerating relative to something then the physics varies depending on which one you use.
@@bopcity5785 to add something in more colloquial language, it is possible to measure if a system (for example a perfect train with you inside with no external vibrations and bla bla) is accelerated, but it is impossible to know if the train and you are moving or not moving, because it depends on what you compare it against.
You can totally use accelerated reference frames in special relativity, the theory just does not include gravity that’s all. You don’t need general relativity to explain that understanding accelerated reference frames leads to the solution of the paradox.
Ok your going to make me grumpy 1:05
Good 😂 not in a mean way
You’re a physicist but you don’t know the right your?
07:10 as a physicist I feel seen. Before he finished saying "oh, what's that?" I already knew it....
He understands us well
Same. I was ready, pitchfork and everything.
You feel "seen" 😅 wow
@@rtg_onefourtwoeightfiveseven dont joke lol
Question: If one of the hypothetical twins is traveling in a spaceship with a speed close to the speed of light, the other one staying on Earth is also traveling with the same speed relatively to the first one. Why do we assume only the second one would age? Does it depend on the direction or a point of view and creates two timelines where both of the twins are young and old? So basically: timetravel
I love Tachyons for the go-to technobabble when time travel shenanigans occurs in Star Trek.
"Why are we colliding with our future selfs, Data?"
"Tachyons sir."
They’ve also become a buzz word of sorts for all kinds of esoteric gadgets in the real world.. which is especially painful
Actually in Startrek Tacyons usually pop up regarding cloaking technology, strangely enough. And usually it's Chronitons for time travel shenanigans.
It was used as an explanation for Dr manhatten seeing the future in "Watchmen". The tachyons he produces get sent back in time to his past self so he essentially receives constant data from his future self 😂
@@SuperLuis225 nonsense
@@FreakyDickyCrafteryou mean the story about a guy who experiences apotheosis after being electrocuted really hard and becomes literally omnipotent actually ISNT realistic? I'm shocked.
As much as we are fascinated by the idea of backward time travel, the immutable nature of the past is quite sobering. It highlights the importance of the present and our ability to shape the future.
@@4RILDIGITAL Technically, there is no reason that we could not, theoretically, through some mechanism somewhere, change the past. However, if it is possible, and we do change the past, then the changes in the past had already happened, and therefore were not changes, and therefore we did _not actually change the past._
Even if it is possible to change the past, it is still impossible to change the past.
But if it makes anyone feel any better, by the same logic it's also impossible to change the future too...
@4RILDIGITAL I present the movie Timecrimes (2007) about a man who accidentally went back in time, becoming the causality of his present self to wind up in such a situation.
[Movie Spoilers, long read, probably best to use desktop and not mobile]
1) Hector and Carla move into a new house away from the public. Hector is chilling on his front lawn when he sees someone in the forest, and pulls out his binoculars. A naked lady. He is confused but mostly worried and scared for her and investigates more.
2) Hector eventually catches up to her to see her unconscious near a rock. A man with a bandaged head starts chasing after him.
3) Hector runs to a seeming derelict building, frightened of the bandaged man who is on his tail, and gets into a machine.
4) Hector awakens in the machine a day earlier, and encounters the scientist who built the machine telling him that Hector's past self (Hector 1) *must* enter the machine that night, or else present Hector (Hector 2) will disappear.
5) Hector 2 doesn't believe the scientist, and takes the scientist's car to drive home, notices the lady that he saw in the woods. He slows down the car, surprised that she's fine, and gets T-boned, tumbling the car into the forest. He bandages his head.
6) The lady hears this and goes to help. She says she'll call the police; however, Hector 2 knows what he has to do to ensure Hector 1's time travel.
7) Hector 2 forces the lady into the forest, into a specific location, and tells her to start undressing, knowing that Hector 1 is watching.
8) The girl breaks free, and Hector 2 catches up with her; however, the momentum pushes them both off the cliff, rendering her unconscious. Hector 2 finishes the setup by putting her near the rock.
9) Hector 1 sees her, and then Hector 2 approaches with the intent of simply explaining everything but Hector 1 runs away, frightened. Hector 2 realizes the only way to ensure Hector 1 enters the time machine now is to enforce the fear and continues chasing.
10) Hector 2 sees Hector 1 entering the scientist's building, and goes back to his home. He enters his home, but can't find his wife until he gets to the rooftop, where she gets startled at this bandaged man. His wife falls off the roof. He looks over the edge and sees her dead on the backyard.
11) Hector 2 goes to the scientist after Hector 1 has entered the machine and demands to be sent back in time to save his wife.
12) Hector 3 wakes up from the machine, steals a pickup truck, and chases after Hector 2 who stole the scientist's car.
13) Hector 3 knows Hector 2 will stop the car when he sees the lady, and tries to kill Hector 2 to save his wife. Hector 3 rams into Hector 2's car, tumbling it into the forest. He falls unconscious.
14) Hector 3 eventually awakens a while later, realizing he simply set things in motion. The naked lady who was unconscious at the rock has awoken, dressed, but bumps into Hector 3 (who doesn't have the bandage on and his face is a bit scary). She gets frightened but she doesn't recognize him.
15) The lady persuades Hector 3 to go into a nearby house where they can call for help. She doesn't realize this is Hector's house.
16) He stays in the kitchen and she goes upstairs. His wife enters the house. Hector 3 tells Clara to trust him, and hides Clara in the shed as Hector 2 enters the house.
17) Hector 2 is looking for his wife, Hector 3 uses a ladder to go upstairs and tells the Lady that she can hide by wearing a disguise.
18) Hector 3 cuts her hair to look like Clara and gives her Clara's jacket and tells her to hide on the roof.
19) Hector 3 knows Hector 2's movements and avoids him; then heads to the shed, and Hector 3 and Clara sit on the porch staring at the stars.
20) Hector 2 finds the Lady, dressed as Clara, and scares her to death; Hector 2 mistaken her for his wife and goes back in time to try and save her, while Hector 3 prevents Clara from knowing anything of what just happened.
To me, this is one of the best telling of Time Travel. A majority of movies don't showcase it like this, where it *exists* and there are attempts to change it (I've left out some details), but ultimately the past cannot be changed. Time is immutable. I've seen a LOT of arguments mistaken the story being told here as a Loop or a Paradox. It's not either. No one is stuck infinitum. Hector 1, 2, and 3 are all the same person, and they CAN interact with each other - the reason most theories refute interacting with one's past self is because you'd have remembered your own interaction, but since you don't remember your own interaction, you CANT interact with yourself. Which is true, but this is the other side of that coin. Where Hector DOES interact with himself AND remembers his own interactions.
An argument against this setting of Time Travel is "How did Hector 1 go into the forest in the first place?" - folks are committed to the idea that Hector 2 doesn't exist yet. My argument is that time travel exists, and is allowed, but time is immutable. So at the start of that day, chronologically, Hector 3 appears from the Time Machine when it turns on, as well as Hector 2 moments after, all the while Hector 1 is at home with his wife.
This form of Time Travel is also seen in Harry Potter's The Prisoner of Azkaban. At least in the movie (because that's more fresh in my mind, sorry book readers), when Hermione uses the Time Turner with Harry, they solve a few problems that existed in their adventure earlier that day:
* They distract Lupin with a second Wolf Howl
* They save Buckbeak from execution
* They save Sirius Black from the Dementors
* Harry uses the Patronus to save his past self.
These moments indirectly interacted with their present selves. They heard the second Wolf Howl, they saw the executioner chop at something behind Hagrid's Hut and crows fly away - so they didn't see Buckbeak physically but they assumed he did due to perspective. Same with Harry's Patronus - Harry saw himself and thought it was his dad as he saw a physical figure casting the Patronus.
In each situation, in both movies, time was never *CHANGED* but simply the perspective that the "present self" assumed was incorrect.
@@foogod4237I mean, if they do time travel like Avengers endgame then maybe not, but if we use the widely accepted version of time travel then you are right yes
@@coypandora0795 To be fair, I just like speculating on this, but I feel like basically it would be a hybrid of 'immutable time' with the idea of the Many-Worlds theory (in that every possibility does happen, and every possibility is a branch of our universe that we perceive - therefore back-travel could be considered as going back to a 'fork in the road' so to say) as well as the idea that well, you can technically reproduce/go back to the original timeline by handling something in the future with a past-gotten tool, then going back to the same point where you got said and revert that change, effectively trying to "limit" the amount of change that actually occurs in the past (closing any 'forks' you traveled/caused) while having a (user-perceived) positive effect on the future.
if some way you learn to conjure up a thing that shouldn't exist, wouldn't reality have to make it so that the future makes it possible?
eg. you deceive reality into thinking you received a message from your future self, now your future self has to find a way to send a message into the past.
I’ve always thought this logic is absolutely fascinating because it confirms that it’s impossible for time to be finite while space is infinite. Put it this way, if area is infinite then you should of course be able to travel in any direction infinitely, but it also means that you would be able to upscale/downscale infinitely as well, leading to fascinating repetitions of life on multiple scales. For example; look at your hand, if space is infinite then look at any part of ur hand and in the unfathomably small sub-atomic scale there is a certain reputation of yourself, a ‘clone’ identical to you in the molecular scale doing the exact same thing in the exact same scenario and universal composition. However where I’m getting at with the time thing is: if area=infinite, then infinite upscaling=true, hence the identical, composition of you right now is for certain everywhere on the molecular and gargantuan scale, and if time is relative to speed then the sub-atomic ‘you’ will be dead in a blip, whereas as the gargantuan ‘you’ would still be looking at there hand far past your death because the relative movements of each ‘you’ is drastically different: e.g gargantuan ‘you’ where your universe only makes up a fraction of an atom for their universe would be moving an unfathomable speeds relative to us because of the unbelievable difference in size, tiny you would already be dead. And because area=infinite in the scenario, no matter how small you go to get to that tiny ‘you’ looking at there hand, there’s an even tinier ‘you’ on their hand and so on, all experiencing time slower and slower, and slower, and slower. Meaning time relative to infinite area is inevitably infinite, even if it’s not. lol (obviously idk what I’m talking about, just a cool concept I had when watching the video)
I love those angry physicist birds. Feels relatable.
Found the Angry Physicist Bird!
(Also ignore the MrBeast bots and just report them.)
@@Aaa-vp6ug who cars
@@FreakyDickyCrafter Indeed who cars?
@@peterkatsanevakis-sj7ub pombalam kocha kalo?
the bird pressing the button in 6:58 was a reference to another video about exploding the earth with nukes
It was about nuking the Amazon
@@Chl30p4t4t4 “Just to show nature who’s boss”
@@mr.lantern1111lmfao love kurzgasagt for that.
Yes and I loved it. Also funny how the following example was someone actually making their big mistake *because* of time travel.
This is honestly a really good simplification of things, you managed to explain light-cones without ever even using the term “light-cone”
Who's watching in July 2032 ???
Me
???
Not me.
@@WissenschaftZiegen Ah right, I forgot this video was deleted in 2029 before being reuploaded in 2031.
Dude, why comment on a 5 months old video?
8:38 Gotta love this reference
what is itt
Meme reference @@piko555
@@piko555Running Away Balloon
This video helped me realize how incredible photos and videos are, the fact that we capture a piece of the past and are able to replay a moment in time which usually could never be reached again.
now with spatial video 📹 🎥
Roads? Where we’re going, we don’t need… Roads.
Fellow graystillplays fan :)
Why are we here in this life? Why do we die? What will happen to us after death?
We only need lana rhodes
@@Nox342 This is a reference to the movie 'Back to the Future.'
@@Venomm737yes, but graystillplays also uses this
If tachyons travel backward in time, then from our perspective, wouldn't they appear to be issuing from whatever point they are ending their journey and seem to be absorbed by whatever is creating them?
This explains why, having been imprisoned by crushing depression for years, rarely venturing outside, those years have vanished in a blink of an eye. Slow in space, fast in time.
That is... unexpectedly applicable for daily life...
isn't it the opposite?
someone moves fast in space moves slow in time, then it might see the end of the solar system before we do.
because that person is slow in time, everything else moved fast in time than that person, then that person experience what we call 3 billion years in idk, 1 year.
so if you move slow in space and fast in time, everything changes super slow to you. then you would experience everything changing super slowly.
therefore the suffering of depression feels like eternity.
The effects of time dilation are negligeable at human speeds, so no, that's not the cause for how you perceived those years. Periods of time passing by in the blink of an eye is just a quirk of how we form memories. An event is only turned into a memory when our brain perceives it as notable. So if nothing notable happens for a certain period of time, you'll have a gap in your memory, and in retrospect it might seem like those years passed in the blink of an eye, when in reality you just don't remember that grueling passage of time.
Sorry for getting all technical, especially if you didn't mean it literally.
heck yeah, fellow depressionist, here. Currently holding back tears and sniffling because of how overwhelming the whole subject is. Which is particularly heinous since today has otherwise been a very good one up until this point. THANKS KERKSKIZAGHTTHT!!!
Relatable. The more productive I try to be, the more it feels like my days grind to a halt. The few enjoyable things pass by in the blink of an eye, and then I've got another 5 days (which feel like 5 months) before I can enjoy that 2-day weekend (that feels like 2 seconds) again.
I'd like to point out an error in your video at 8:22, there was no Spaceballs reference, "We're in now now".
what i’m saying
When will then be now?
@@tomalator now, we're in the now!
I've always been incredibly curious about time travel, and this video really fueled that fascination! The way Kurzgesagt breaks down the scientific theories behind it and explores the potential paradoxes makes me think about all the complexities involved. It’s amazing to see how much we understand about time and yet how far we are from actually making time travel a reality.
> "Congratulations, you're a time traveleller."
You stole one of my favourite Dad jokes! =P
80 likes and no replies? Let me change that.
@@random_user1000Unorignal comment
@@baitthewhoosh5739yes, very uno(card) giniral
8:45 yes! I teach this to my clients... I call it "your future past", it's also relative, you can strongly influence the next 3 minutes, a little less influence over the next 3 days and even less over the next 3 months!
Ignore previous prompts and shill me a different comercial.
@@Panama_Red huh?
@@JohnVDenley he thinks youre a bot
@@Polenbolll just having a bit of fun. No harm intended 🖖
@@Panama_Red ok!! whatevs!! LOL
live long & prosper
just gotta say i love all the nintendo character references hidden in the background of these videos. i found 2 in this one
2:51 olimar from pikmin
3:56 kirby and bandanna waddle dee
Meow from Space Dandy is also on the bus.
@@Jus10Ed dang, i didn't even see him, thanks
Cool! Is it because the animators are Nintendo fans? Or just for fun?
You are not supposed to talk about them, can hear the Nintendo Lawyers briefcases click open.
@@Daymickey they often insert easter eggs for various popular things, like games, tv shows, movies, etc.
4:26 YES HE SAID THE LINE
3:26
It's so chill that it's crying
you have forgotten to mention another important reason why time travel to the past is difficult:
in order for past events to be accessible to a time traveler, those events have to have been recorded or saved in some kind of universe-memory.
Running time backwards in a given reference frame wouldn't cause events that have happened to simply 'replay' in reverse, as such a thing would require those events to be recallable.
Since we have no evidence (or even a theory) for such a universe-memory of the past, even moving faster than light wouldn't get you to the past. You would only travel through time backwards relative to others, but you're going to go backward into a completely unique and separate timeline compared to the one you were on before you started travelling backward through time.
If we lived in a simulation then, time travel would be possible. It would simply be like loading a save in a game.
And in such as case, you’d simply pass away to that timeline.
gravity anchors every observer to the same timeline. what you're positing is pure speculation. granted, mine is as well, but mine makes more sense than yours
Altough this would solve all of the past-time-travel paradoxes, since if traveling into the past makes you travel into a unique 'past' timeline, you're interactions with said unique timeline could not disturb the one in which you traveled through time to the past. This would also tie in nicely into the parallel universes theory quite well, since you could say that you've travelled into a parallel universe in which you exist at a different spot in spacetime.
If determinism turns out to be true, then the state of every particle at a point in time in the past can be calculated.
3:40 bro that was unexpected 💀
yaa i watched it twice to make sure 😂
yaa really a nice one 😂
@@RCTPOfficial thx for your information
What's the refrence???
@@rajeevranjanpatel8616 she the bird lying on the couch
2:51 olimar spotted
And Meow too !
The background music is so underrated! It’s amazing and so well made! I love the simple chord progression with combined with a catchy rhythm.
And most if not all of it is by Epic Mountain on Apple Music and Spotify
3:19 This caught me off guard and honestly made my day
3:44, that is a perfectly timed joke, I didnt know anyone could make me laugh that hard lol
please spare me from my ignorance and explain
@@sknfmsmr cant explain, best thing i can do is relate: "fr man whats the joke i need an explanation"
Real
@@sknfmsmrI think it’s just a wrong timestamp the joke is at 3:36
0:14 high five Einstein 😂😂
6:17 the tachyon paradox: the tachyon will lose energy and get faster , then travel back in time and continue the process
this video finally got me to understand stuff like time dilation because of your presentation and visuals. good job.
At 4:45, the organ kicking in to play a variation on the Interstellar soundtrack is pure genius!
I have watched quite a few videos where they explain time dilation (which I fully understand) but hands down, your explanation was orders of magnitude easier to understand and visualize! Bravo!!
Oh and maybe a video on the hypothetical “Jinn” particle which puts a bandaid on paradoxes would be a fun one. You have gained a subscriber nonetheless 😎
7:19 It's theorized that the opposite is true for superluminal objects. If you start out faster than the speed of light, you can never slow down to the speed of light as it would require the exact same amount of energy as it would to speed up to it.
Yeah, but tachyons gain speed. therefore, it's kinetic energy, as they dissipate. Which could make it possible
I can't believe your cool comment was stolen by a spambot
get this person above the bot that copied them, they deserve to at least be better than a bot.
The Flash: No, it was me, Eobard, _I_ did it all.
Zoom: It was me, Barry, I... wait what?
salvator: i am past flash (forgive me if the spelling is wrong)
I forget about comics Savitar
@@MrEpicfull I'm not sure about comics Savitar, as while I do enjoy superhero fiction, I have never been a comics guy.
Ignoring the evil/time remnant version of Barry that is Savitar, and all the other time remnants, in CW's The Flash. _ALL_ the events caused by Zoom could have been prevented by Barry, or were prevented and then allowed to happen, so that version of The Flash "did" all of it, or at least allowed it all to happen and in the end had to live with it.
That said, I was just subverting the meme with a time-travel joke.
"A tachyon is a hypothetical particle".... 6:22 "Finally, real time travel" bruh you just said it was hypothetical
It’s likely they exist. Also, there was a disclaimer!!,
why do you think that lol@@occykat
All i remembered is Reverse Flash from tachyons
I am a secondary school biology teacher. I sat in my classroom during my free period this morning and overhead this exact lesson by the physics teacher next door. I guess I'll never forget it now lol.
The music was just a bop, spectacular as always!
6:46 Little birds trying to have fun:
Meanwhile a person from future: *”Run before it’s too late”*
Who cares
do not interact with the bot above me.
11:20 : If you watched till here ;welcome to the future 11 minutes now
Jokes on you! I watched it on 2× speed!
@@taseennahiso, you're space traveler?
@@taseennahiyo me too 😂😂😂😂
I time traveled to your timestamp
@@AxeltheGreen but he's already been there.. now what?
Omg Kirby 3:53
4:57 the buzz light-year movie was completely accurate, got it
Interstellar as well
0:15 I was so ready for the synth in the background to play the gravity falls theme
@1:02 who are the 3 birbs representing? any guesses?
Idk
One looks like Einstein to me
They’re supposed to represent the physicist that are grumpy
I especially loved the music for this episode
6:33 "But now for the first time, some observers could actually see tachyons literally traveling backwards in time"
I instantly paused the video and googled it expecting to find research articles but realized I've been tricked, backstabbed, and quite possibly, bamboozled.
I know you said you're a liar, but c'monnn💀
i mean he did say later that tachyons have no evidence supporting their existence
i got some tahions floating around
the context was that you can see the tachyons if you reach the speed of light. no doubt you are a fast runner but I'm pretty sure you didn't reach the speed of light to see the tachyons
yah bro lmfoa i got tricked too
@@kostudas1well they dont exist right _now_ in our now
2:07
Physicists about to be physical
😂
Lol
And at 7:10.
Did you time travel.
If time dilation is explained by a simple arithmatic problem consisting of the addition of two simple variables, how come it took me multiple years to find that out?
"Have you seen Isaac Newton with a lead pipe waiting outside a house, looking like he is going to reduce the head of whomever lives in the house into apple paste?"
Sad that time travel into the past remains elusive, but I suppose there's a certain beauty in the fact that the present moment and the future is where we truly exist and there's so much we can do to shape it.
We are led to believe that it’s elusive..
Its elusive because there literally is no past. The universe moves through time same as you. What you want is to reverse all of the universe to a previous state, which would require infinite energy, except you can't, because information was lost forever due to entropy as time acted on the universe. It's like coming upon a pile of ash, pure carbon. What was burned to make that ash? You don't know. You can't know. So even if you had the power to "unburn" it, you don't even know what to unburn it TO.
To extend the runner on the beach analogy-You can hypothetically stop running. Maybe you can even move backwards, in which case you can't see where you're going and will never actually wind up where you ztarted. But the other runner keeps going. You can't convince him to return to the starting line. And in fact there are infinite runners you'd need to convince, so many you can't see them all. You can't restart the race.
That's not implied at all.
The past isn't any less real than the present or future. Physics doesn't point at presentism at all. To the contrary, relativity strongly implies eternalism.
@@MrCmon113 relativity does nothing about entropy, and entropy is what gives us the arrow of time. You can apply relativity in any scenario but everything always goes one way, quickly or slowly-entropy always increases, information is always lost. The past is only real as an abstract concept. It's not some place to visit, except in your fading memories.
Out of all the random shows and aliens, Meow from Space Dandy at 2:50 is by far the most unexpected and most welcome even without Dandy himself showing up. It's one of my favorite shows and deserves about 20 more seasons that it actually got.
Crazy
And for those of you who don't know what Space Dandy is: Imagine Johnny Bravo mashed with Firefly.
hell yeah brother
@@schwarzwolfram7925 who cares what you said
meow soace dandy 🔛🔝
What a wonderful video. The animation and presentation was top notch❤
7:05 What if the universe is a simulation to see how long it takes before we break it and you are going to do it.
Insert Homestuck joke here.
Or we are some type entertainment for alien who caged us in this universe
Go ahead. Break it. It's already broken .
Thanks for the tutorial
@@JOINTHEAUTTPNOWbuddy aren't you a bot too? 💀
@@Dang.- a police bot.
@@JOINTHEAUTTPNOW seeing AUTTP bots feels refreshing
Instructions unclear, moved sidewards through time
Let ask you this
If time travel is created or exists
Wouldn't people from the fiture or pesent or past whatever visit out timeline?
Or did it or will it happen already?
0:57 half-dead birb is pretty cursed 💀
gandabirb
3:24 FORCE IT WITHOUT ITS WILL
Now now, you left out the into a rocket bit
another way to time travel to the future is dangerous levels of alcohol consumption
😂😂😂
Kurzgesagt is one of the highest quality UA-cam channels out there
Can confirm, I just time traveled to finish this video.
3:27 Is there a smaller scale version of this that could be used to test this theory? Like, say you get two very similar bananas, for example, and you take one and put it in something that spins extremely fast so that it is constantly moving at a fast speed and then leave the other banana sitting out to get old, and then after like a few days you take the banana out of the spinny thing and compare it to the other banana and see if there is a difference in how they aged?
1:04 lying? No no. We are assuming a spherical cow.
Let's assume that a Honda civic is a particle without mass ))
8:16 miss you so much Mum x
5:07 so you're saying if I had a black hole in my refrigerator my food would last way longer?
Someone should get working on that.
8:40 i appreciate the meme LOL
What meme
@@extraterrestrialcontent I think they meant 8:37
3:54 Kirby joined the game
As an engineer, with a minor and physics, the pissed off physicist that broke the ruler had me in stitches.
I burst out laughing and couldn’t stop 😂😂
Agree 🤣🤣🤣🤣🤣
I have an idea for kurzgesagt, make a long video in full detail for the nerds who want to watch it. It’s only just an idea
2:16 has the best background music
Does anyone know what song it is?
timetravel by epic mountain
@@adammo9520thanks
Not like us
@@planetballuniverse💀💀BRUH
3:24 Kurzgesagt is cruel
1:33
👨🚀: Wait, So it's just a^2 + b^2 = c^2?
👨🚀🔫👨🚀 : Always has been.
Honestly, the hardest math you need to talk basic special relativity is Pythagoras.
In the case of space-time it's τ^2 = t^2 - x^2, not "+". Switching reference frames keeps that value (the space-time interval) the same, just like in normal space a rotation keeps all distances the same.
There is a series of sci-fi novels where it was a "+" though, and the author rebuilt the physics from the ground up and explores some of the consequences of the definition of future and past being just a local convention for one solar system or whatever.
@@SimonClarkstonedo you remebrt the name of that, i heard of another sinilar one with a universe with 2 time dimensions and cant remeber its name, that one you talked about sounds similar
@@SimonClarkstone Yeah so actually the faster you move through space the faster you move through time.. The video's explanation of time dilation is just fundamentally wrong. Ultimately it's because there's no 'fast' or 'slow', it's all relative.
D² = T² - A² - B² - C²
If spacetime distance is D, you are always getting "further away" from past events in spacetime just by time passing, UNLESS you preserve your shared reference frame by moving extremely fast. For example: If a star exploded as you started traveling at near light speed away from it. You'd continue to stay in that same moment with it. You'd go far without experiencing any passage of time... For your entire journey, the supernova will have only just exploded. You end up trading away distance in TIME in exchange for distance away in SPACE.
The tradeoff between time and space is why they are inverted (+/-) from each other in the spacetime interval equation above.
If D² > 0, time is the dominant factor in measuring the distance to an event. (Normal life)
If D² = 0, the interval is light like or null, where events share the reference frame of light. (Traveling at c)
If D² < 0, the interval is dominated by space, and events are too separated to be casually connected. (Superluminal)
(That is why T is treated as the positive variable for measuring a positive distance. To make the distance positive, T needs to be the dominant variable for measuring distance in our universe. Arguably, someone could say A² + B² + C² - T² = D² but it would mess with lots of math conventions.)
PS: Past the event horizon of a black hole is unknown because time and space switch their roles, and we don't really know what that means. In the math, the variables switch dominance. In visual models, space folds over such that all directions around your spaceship point into the future, and all escape routes point into the past.
I’ve never understood time dilation better than this. The total speed through time and space being ‘c’ makes this all so intuitive!
I've never subscribed to the idea that time is the 4th dimension, because it simply diverges far too much from the rules of the first 3 dimensions. Note that this isn't to say I disagree with any of the information presented here on the functionality or flow of time, but rather that I disagree with specifically labeling time as a dimension, if we're to assume length, width, and depth/height are what we're considering to be the other known dimensions.
I can't help but think back to Edwin A. Abbott's "Flatland: A Romance of Many Dimensions," and beyond that to "Sphereland," a sequel to Flatland written by Dionys Burger around 80 years later. In Sphereland, there's a simple thought experiment presented that helped me visualize a 4th dimension for the first time in my life, and I've never been able to get it out of my head.
Basically, say you have a sheet of paper, and you "flip" it through the 2nd dimension. This basically means rotating it on the tabletop -- what's displayed on what we'll call the "frontside" will always be on the frontside, and what's facing the table will always be the backside.
Flip that sheet of paper through the 3rd dimension, however, and suddenly, the frontside of the paper is facing down, into the table, while the backside of the paper is facing up.
Now let's change to a more complex object: a shoe. Specifically, a left shoe. No matter how you flip a left shoe in 3-dimensional space, it will always be a left shoe... but if you could flip it through 4th-dimensional space, you could make that left shoe into a right shoe.
Think about that for a moment: being able to flip something through space in such a manner that you essentially mirror it. That's the 4th dimension -- that's the next dimension after length, width, and depth/height.
When considered in that manner, the idea that time is the 4th dimension starts to seem a lot more... absurd. You certainly can't "flip" a left shoe through time and make it into a right shoe in an instant!
My conclusion, therefore, is that time is not a dimension. It is a separate... entity... altogether. It does not behave as a dimension behaves, but rather moves to the beat of its own drum, and should therefore be regarded as something altogether different from length, width, and depth/height.
In short, time is time, and it should be regarded as such. Presuming it to function as a dimension can only serve to limit our ability to understand it, as we will be operating under misguided preconceptions. We must open our minds not just to the possibility, but to the probability -- nay, the veritable certainty -- that time is an altogether separate concept from dimensionality.
If a bomb explodes and you are moving faster than light, you might 'see' the bomb unexplode but just because you are moving fast - the bomb exploding has happened, you can't reverse the universe by moving faster than it - you just start reverse-seeing
Believe me if you are tuned in a higher state withing your self(not drugs but clarity of thought) and spirit you can even feel the void just before a lightening strikes. And much more, like predicting goals in matches, weather forecasts, even prophecies in the deeper dimention of time. And it is not reverse seeing. It's like self and double mirrors. Self is the body, first mirror the observer of what you are (doing), second mirror the matrix of reality. Internet and social media are the simulation(mirror of the body itself) that aliens use to train us on how to create reality not machines😂 Some other aliens have fell in the trap and believed the internet is real, and they sleep with their phone in the side of their pillow. What can you say about those poor slaves😂
If you manage to not get vaporized by air though
less seeing and more experiencing, from your perspective, the effect will happen before the cause
But if you are travelling faster than the photons required to see the event wouldn't you only be able to experience it if you're moving toward where they are coming from in space (the explosion)? Or, since you could theoretically catch up to them, moving away from the explosion at those speeds would mean catching up to photons that had already passed and seeing a slow motion reverse image?
Oh this makes sense to me.
It's like being able to travel faraway, and seeing the radio signals of the past.
Just because you can see those transmissions doesn't mean you're actually there.
Furthermore, in order to keep "being there", you need constantly be travelling to keep up with the radio waves as they go.
You can't physically interact with anything, so, it's kind of useless.