I did an undergrad in physics, which is only enough to kind of get things. This stuff only really makes sense when speaking in math, and that math is often partial differential equations. It is rough. But hey, it sounds so cool when he makes it seem almost intelligible!
That's the beautiful thing about outer space and astrophysics and what not, so many unknowns while the little that we do know is jaw dropping. You just wanna know more
Who else tries to see how long you can try and pay attention and understand what he is saying until you eventually snap out of a thought and realize you have been drifting about in your mind for a few minutes now and are completely lost.
Thats the point, nobody understands it, not even physicists. I mean, they understand parts of it, but thats why he is asking so many questions rather than answering them. Science always leaves you with more questions in the end.
I try to watch, rewind a few minutes, watch it again, rewind again.. and do this around 4, 5 times. Then I give up. But it gives me a feel good feeling to know the Universe is infinitely more mysterious, crazy and interesting than any scifi ever made.
Brainjock he always does. It’s pretty much expected that the the viewer has some prior knowledge in astrophysics and cosmology as well as quantum... yea, I would just watch as much as you can and over the years you will soak it up if it really interests you.
Seriously. I tried physics and astronomy in college and even though I learned a lot it wasn't for me despite how much I adore both of them. I'm focusing on being a psychologist. This channel allows me to continue learning at a significant rate, it even increases in complexity when you get to things such as the holographic principle. It keeps the mind seriously engaged.
I really wish youtube and channel like this were available when I was younger, I would've been much more likely to get into math rather than asking "What am I going to ever use trig for?"
Exactly. We're taught to hate and fear math because it's usually taught in such an ass-backwards manner. If only we were shown at a young age how fascinating it is.
@@mandaJt I was in the 3rd quarter of calculus based physics in college when I realized I was finally learning all the things i desperately wanted to know in grade school but nobody would teach me. And I thought: man, why couldn't they have taught me this back then, I wouldn't have nearly flunked out of middle school before my folks brought the hammer down about studying. And then I realized that all the folks I was helping in the math lab as a tutor were elementary school education majors who could barely pass basic algebra with loads of help, and it all made perfect sense.
I'm following a course on General Relativity now at university, and for the first time in my life I have watched a PBS Space Time video and understood nearly all of it
Great! Maybe you help me understand something then. Assume you could actually travel at the speed of light in a spaceship, then all distances traveled are experienced as an instantaneous trip for the people in the ship right? So if you wanted to travel to say, the center of the galaxy, you could calculate and plot your path in space, sure, but how would you know "when" to slow down the ship to arrive at the right point along your trajectory? Is it even possible?
would you be able to feel spaghettification? Would you feel nothing because time is still or feel it forever (for lack of a better word)? - a confused Canadian.
I started watching Spacetime about a year ago from the first episode. I have finally caught up with the episode that came out when I started. What a brilliant channel! Thank you.
"There once was a fellow named Dark, Who entered a black hole on a lark Time became space and space became time And he compressed to the size of a quark." -EH
"There once was a girl named Bright; Who could travel much faster than light; She went out one day; In just such a way; And returned the previous night." - Niven
The way I've heard it, the limerick goes something like this... "There once was a lady named Sprite; Who could travel much faster than light; She left one day; In a relative way; And returned the previous night."
I think we've all either heard or made up slightly different versions of this and most other limmericks, lol. Mine is: There was a young lady named Bright, Whose speed was much faster than light. She went out one day In a relative way, And returned the previous night!!
In college I was always at or near the top of the classes I took. But I wasn't taking physics or very high level math classes. The brain this guy possesses is so much more intelligent than my brain and it's not just him. In my life I've run across a lot of people who are insanely smart. I would say I only understand about 30 percent of what this guy is talking about and the amazing thing is I keep watching and listening anyway.
To me there's always a big difference between people who know how to store information and people who know how to process information. It's ofcourse a plus to be able to remember a lot of info, but what's the use when you can't see the connections
I saw the title and thought, "there's gonna be Penrose diagrams!" And behold, there were Penrose diagrams. I learned about those from this channel. Thanks!
...and...with that in mind, I've also been that "hyperintelligent by comparison" in other environments. Kinda unsettling how little it takes to be considered a functioning adult, with that said.
It’s all about understanding and analysis. Just because one understands more about a specific subject matter does not mean they are more intelligent they you.
@@lukeskywalker4939 Agreed. Also, just because someone can fulfill the tasks which lead to their grade doesn't mean that they have a good understanding of the subject matter. It's frightening how many students now (after a generation of massive standardized testing) expect that a given question has a specifically worded answer rather than being able to work it out from the previously learned material. I.e., logic & critical thinking are quickly disappearing, even among university graduates.
To use a worm hole you would have to survive the near infinite density and your atoms being torn back into elementary particles or even some lower levels of time/space/particles we are unaware of. An infinite number of possibilities come from fantasy mathematics beyond the event horizon. The realm of the densest part of a black hole is probably unobtainable in experiments and the real physics of the super dense probably will never be known. Extending what we observe into the area is a logical approach but most likely doesn't come close to the reality of the real black hole.
well, at least he is trying to pronounce all properly and is improving over time. Not every scientist is english speaking, so you have a lot of german, french, russian, etc scientist as well, after whom are certain things named. so he has a lot of names, that are pronounced very differently, from what you are used to in english.
I always used to think a black hole was an actual hole when I was younger. Then I learned more and believed they was just incredibly dense mass with such gravity even light couldn't escape. Now I'm back to square one
at Herbert Miller -- Does that preclude everyone making web videos (or content) going back to at least the start of Feb 2020 put a disclaimer on every thing they produce? Or mabye you simply infer that people would be too dumb to correlate the historical events of 2020 and figure it out? Go search for photos of 1930s era depression lines ... "Gee, I wonder why all those people are standing in line, must be for concert tickets? No wait .. that sign says 'free food'; must be either 'normal' homeless or a promotion at the restaurant in the picture; couldn't possibly be a national depression, because ya know there was no Internet back then". Based on your comment, I kind of put you in the latter. PS - Make sure you label your comment so people 20 years from now know WTF you're comment is referencing.
I’m wondering how seriously we should take the idea of just extending maps to see what they look like. In sticking with the comparison to maps of earth, I can imagine someone saying “the lines converge at the north and south poles, so if we extend the lines, we can see that there’s mirror reversed earths stuck to the north and south poles, as the longitudes diverge again.”
My thoughts exactly. Penrose diagrams are just a model that fit our observations of the universe. They are not a rule book that the universe follows and it’s quite possible that the penrose diagram would simply not work when trying to explain what happens when you cross the event horizon
Question: According to the theory of Hawking Radiation, a black hole may eventually evaporate away (in a very very long time) right? In addition, when one is falling into a black hole, time slows down for them and they see the universe behind them with its time accelerated faster and faster. My question is, that is it possible that the black hole would dissolve before the person reaches the singularity? I might be wrong in most of what i said lol
This was answered in a previous video about black holes, you don't actually see the universe in fastforward when passing the event horizon because your past light cone does not cover that part of the diagram. Or at least that's what i understood of it.
The black hole bleeds energy ergo mass via this radiation. If it looses enough energy, shouldn't it cease to be dense enough to be a black hole? Or does it shrink in diameter?
I was wondering myself. Apparently, regarding the universe, you wouldn't see it accelerate unless you fire your rockets in order to slow down your fall and try to race away at near light speed. If you instead stay in free-fall, you will see the universe at a normal pace. Regarding the Hawking radiation, I found this: physics.stackexchange.com/questions/22498/from-where-in-space-time-does-hawking-radiation-originate. The diagram on the site shows an evaporating black hole, and apparently the horizon is at an 45 degree angle even in that case. That suggests that once you're in, you're doomed as usual. It's far from clear to me what happens to spacetime at the point where the black hole evaporates though. Maybe a good topic to ask for a future video? :)
What if the "edge" of the universe was an inside-out black hole, or at least acted as such? Imagine a flat plane that only seems to stretch out infinitely, but if you were to zoom out enough you'd see the edges start to curve downward until they drop off straight downwards infinitely, just like the flat plane representation of a black hole. The resulting diagram would be shaped like a really big cylinder. I've watched so many of these I can't recall if this idea has already been thought up or not, but i thought I'd bring it up anyways bc i think its an interesting alternative idea to what the "edge" could be
By an "inside out black hole" do you refer to a white hole? Because if the "edge" of our universe were that, it would emit a lot of light and repel things from it with great force. Not only does that go against all the findings of the nature of the expansion of the universe, which is going outwards not inwards, but it also would likely negate effects we see like red-shifting and Hawkings background radiation. If the edge of our universe was specifically something that emit a great deal of light and gravitational force, I imagine that would be observable at some point when you get those star images where you can zoom into darkness and it reveals hundred of millions of stars packed together. I think a more accurate image of our universe would be a shape we can't physically imagine because all of its sides would be connecting to the opposite side, sort of akin to a sphere, but if at any given point on the sphere it connected to the point directly opposite of it on the other side of the sphere. The Universe very specifically does not have any sort of edge, and the PBS guy specifically mentions that being a bit of a problem in interpreting the flat plane representation of our universe. Just like how things get disproportional on the map of Earth, the Universe map is disproportional because it's intentionally putting an "end" on things that are infinite.
@@tanner.mackey.mp3 No i wasnt thinking quite like a white hole.... I was just imagining a spherical boundary (assuming one can be assigned) around the universe that acted similar to a black hole, in that it attracts matter in some way as an alternative way of explaining why intergalactic space is expanding faster than we think it should be. Idk, in hindsight it probably doesnt make too much sense now, honestly just trying to think creatively to keep my brain from rotting in quarantine lol
Is the word "mess" in some way an apt term for it? If not, there's no sound reason to make the acronym. It's this same misguided thinking that leads to stuff like "G.O.A.T.", whose connotation is pretty much the opposite of what that "term" means.
Dr_Owen Maestro To the casual chap, to "expand an equation" is to annotate every part of a shorthand variable. An example might be to write '9.8 m/sec/sec' instead of the much simpler notation 'g'. So a maximally expanded equation would seem, to someone not well versed in the math of such complex physics, to be quite a mess of numbers. Of course, finding humor in such things is always subjective. Humor or distaste, your perspective is as valid as anyone else's, and I appreciate you helping us drive the engagement algorithm for this great series.
It's simple. He goes into the black hole, some timey whimy wibbly wobbly stuff happens, he sends a text message to his daughter through Morse code through a watch, some more timey whimy wibbly wobbly stuff happens, he gets spit out of the black hole. The End. PS I don't know how to spell whimey.
Dan Kuchar maybe "whimey" with an E. "Whimy" would be related to a "whim" and we're looking for more of a "whime". Feel da whithym, feel da whime, come on Jamaica, it's bobsled time!
He fell into a structure that future humans will build and hide inside the event horizon of a black hole. That structure kept him from dying in the singularity and let him travel freely in the time dimension to find the perfect time to send a message to his daughter.
If space is infinite, doesn't that suggest that any "parallel" universe, is really the same universe as one parallel to it? If the universe is infinite, surely you would never be able to tell if you were in a "different" universe.
Listening to Matts lectures is a bit like a Penrose diagram, everything is going fine then suddenly everything goes off in a tangent and im like by by 👋 aint got clue
This channel needs a cliff notes or A for dummies section. I completely understand other people when they talk about this stuff. For the most part. I come here and quickly realize... I never know what they’re saying at all lmao
7:55 Why do all other sources say the Einstein Rosen Bridge exits to the top of the diagram into a white hole (the singularity replaced by a bridge) rather than to the side, and does not require superluminal travel? I think you even do in your white hole episode. Totally confused now.
They are both valid. The one requires passing through the singularity and emerging out of a white hole into a different parallel universe. This one skips the (probably) certain death of the singularity and instead escape out of the black hole into a parallel universe.
cmilkau This video only looked at going through event horizons, which involves superluminal velocities and takes you from an area of normal spacetime through an area of warped spacetime into an area of normal spacetime. Things dealing with wormholes tend to look at traveling in to a singularity in the centre of warped spacetime and then traveling away from the singularity, which is a 90 degree offset to the theoretical universe to universe examples in this video. It just depends on what direction you’re traveling in the Penrose diagram.
@@kylelochlann5053 Never heard if that one either, interesting. The X being a coordinate singularity, though (you are infinitely far in space or time from everything definite), I think everything could be there. Or nothing. You could have a big bang with a primordial black hole infinitely in the past and it would still look pretty much like this.
@@ToddSkelton I don't think there is a parallel universe in this diagram, at least if you remember that three spatial dimensions are collapsed into one. A sphere in a 1-dimensional space are two points. Add time, you get two lines, that is the big X in the diagram. In 2-D, however, you get a double cone, and its exterior is connected. Basically this just says you can walk around a 2D black hole, there is no other side. Now in 3d, it's much the same as in 2d, you just have more choices to walk around a ball than a disc, but other than that, there is still just one universe.
Was it this show, or was it "Infinite Series" that did a big series on the Penrose diagrams.... I think minute physics also did something. I miss Infinite Series
Easy equation Simpsons = culturally irrelevant. Sad to tell you that, todays cultural hotspots for relevant pop cultur in the animated tv realm lays in Southpark.
The part near the end reminded me of how travel between the two universes occurred in Fringe. To travel between the universes two objects paralleling eachothers mass needed to be simultaneously ejected into the other's universe preserving the balance of matter between both universes. In this sense, a black hole / white hole would act as the equal sign in what was, for lack of a better term, a massive universe sized equation in which the law of preservation is able to be maintained. From the perspective of the traveler they bridge the gap between the two universes and emerge out on the other side but from the perspective of observers in the two universes the individual would parabolically approach the black hole only to suddenly reverse course and emerge back from it. The show never quite used black holes to do the traversal but instead used pseudoscience and later on in the series psychic mind power induced woo to achieve the exchange. But in a more real world scenario the exchange of matter might make sense up until the point where the shift in angular momentum occurs. At the bottom point of the parabolic curve where the two items of equal mass exchange their universal coordinates, the exchange would hit the same roadblock of approaching infinite time unless FTL or other yet to be discovered methods of solving the equation / bridging the equal sign are involved. The image of the traversal of the singularity via FTL means appearing to be a reversal of time reminded me somewhat of the show so I figured I'd share. Not a physicist, just watch a lot of these videos as a hobby, so apologize if my understanding is way off, lol!
Yeah, I was going to point out the exchange of matter isn't really happening between black holes and white holes in a back and forth sort of way. At the very core of our understanding of black holes, they take IN matter and light and condense it nearly infinitely to create a singularity at the center of the black hole. White holes have never been observed and are purely speculation at this point. If a white hole exists, it would be the only version of the two that things would be coming out of. Like the guy said in the video, if an object or photon goes past the event horizon of a black hole, it is NOT coming back. An outside observer would watch it shift colors and slowly fade, and an observer inside the event horizon would observe the object get spagettified and compressed until it became part of the singularity itself. So the whole exchange you're talking about wouldn't be possible without two black holes and two white holes, and then some (currently impossible) means of communicating between the two universes.
Also, the universe itself doesn't seem to care a whole lot about the balance of matter versus anti-matter. It's only independent matter itself that can't be created or destroyed. If matter were to enter into our universe from some portal from another universe or whatever, our universe would almost certainly be indifferent to it.
Wow! Thanks for the thorough clarification. I am grateful for your time in explaining it to me and not calling me out on my layman's understanding of how this stuff works. Some people can be total pricks about stuff like this, but you were very kind to take the time to explain it nicely. Wish more people on the internet were like you ;-)
@@tinyguy9398 hey man I'm always happy to help spread knowledge, and I appreciate your appreciation lol. Some people get really hostile when I try to explain something they seem to misunderstand, so I'm also glad you were graceful in receiving my information.
So if Termina really is, in the Penrose sense, the parallel to Hyrule, then that "portal" in the Lost Woods really is exactly that. No wonder the Hero of Time was away when the Hylian Alliance could've used him during the war against the Gerudo after his defeat of Ganon in Ocarina of Time. By the time he returned after ridding Majora's Mask of its evil, Ganondorf had already been banished to the twilight realm at the expense of one of the sages. Fast forward to the events of Twilight Princess, where the master plan set by the Hero succeeds and Ganondorf is killed for good, only to later be reincarnated per the curse placed on the Heroes by Demise. That portal may also be the reason the Zelda adult timeline didn't have a hero until the Hero of Winds (not even of the Hero of Time's own bloodline, unlike the Hero of Twilight) showed up and killed Ganondorf almost the same way the Hero of Twilight did. So "Hero of Time" is even more fitting a moniker now!
they are physical. We use them to map our location on Earth, in our solar system, in our galaxy. Spacial and temporal coordinates represent the four dimensions we have freedom to move in, with time being just as real as the spacial ones. We require four coodinates to describe our location at any given time. sometimes we can get away with just two coodinates on earth as a two D position of longitude and lattitude, if time is not needed The coodinates are just the measuring rod of the dimensions, be it distance or duration. As an example of how all four coodinates are required to precisely give our location at our given time, and an example where the time coordinate is essential, Imagine, if you will, two separate locations - a point "A" and a point "B" - connected by a path. Imagine that you have one person who starts at A while the other starts at B, and they each travel towards the other point. You can visualize where each one is by placing a finger from each hand at A and B, and then "walking" them towards their respective destinations. There's no way for the person starting at A to get to B without passing by the other person, and there's no way the person starting at B can get to A without passing the first person. In other words, in order for each person to arrive at their destination, there will need to be a moment where each of your two fingers occupy the same spot at the same time. In relativity, this is known as a simultaneous event: where all the space and time coordinates of two different physical objects overlap. This is not only non-controversial, it's mathematically provable. This thought experiment explains why time needs to be considered as a dimension that we move through, just as surely as our spatial dimensions are dimensions that we move through. And the coordinates X Y Z and T mark our position spatially and temporally in dour D space-time. Just as surely as coordinates map our two D location on Earth. Be sure to consider coordinates as physical when you use a satellite phone to call in for emergency rescue if you ever get stranded with hypoxia while climbing a very high mountain. . It wasn't Einstein, however, who put space and time dimensions together into a singular formulation that left them inextricable. Instead, it was Einstein's former professor - Hermann Minkowski - who figured out how inseparable these two entities were., which gives rise to us requiring four coordinates to describe our location. Less than three years after Einstein first introduced his Special theory of Relativity, Minkowski demonstrated their unity with a brilliant line of reasoning. If you wish to move through space, you cannot do it instantaneously; you have to move from where you are right now to another spatial location, where you'll only arrive at some point in the future. If you're here now, you cannot be elsewhere at this same moment, you can only get there later. Moving through space requires you to move through time, too. If time weren't a dimension, a coordinates, with the exact properties it possesses, special relativity would be invalid, and we could not construct spacetime to describe our Universe. We need time to be a dimension inextricable from space for physics to work the way it does. and x y z and t coordinates are very real. Demonstrably so both mathematically and in real life.Plus even the most extreme mathematical calculus and algebra of general relativity turned out to be real phenomena-e.g. black holes. So maths, coordinates e.c.t. these numbers are not abstract imaginary numbers, they describe real things. Maths describes reality.
Of all the channels on UA-cam I don't understand, this one is my favorite.
Lol so true
I did an undergrad in physics, which is only enough to kind of get things. This stuff only really makes sense when speaking in math, and that math is often partial differential equations. It is rough.
But hey, it sounds so cool when he makes it seem almost intelligible!
Agree
That's the beautiful thing about outer space and astrophysics and what not, so many unknowns while the little that we do know is jaw dropping. You just wanna know more
Exactly what I was thinking.
“Not only is the Universe stranger than we think, it is stranger than we can think.”
― Werner Heisenberg, Across the Frontiers
@To The Point 2020 lmao
less of the 'we' Mr Heisenberg
"Say my name" - Heisenberg
It's only that strange because our theory about it is so ridiculous.
J B . Wow that's very true!
Who else tries to see how long you can try and pay attention and understand what he is saying until you eventually snap out of a thought and realize you have been drifting about in your mind for a few minutes now and are completely lost.
🙋🏼♂️
Thats the point, nobody understands it, not even physicists.
I mean, they understand parts of it, but thats why he is asking so many questions rather than answering them.
Science always leaves you with more questions in the end.
I try to watch, rewind a few minutes, watch it again, rewind again.. and do this around 4, 5 times. Then I give up. But it gives me a feel good feeling to know the Universe is infinitely more mysterious, crazy and interesting than any scifi ever made.
Thank goodness for the comments or I would have fell asleep on the toilet 🚽
Hehe what are you talking about . It is clear as mud
I feel like the guy who realised he is sitting in the wrong class on the first day.
lmao
This was me on my first day of embryology in med school, I might as well have entered into an intermediate mandarin course 😅
Me but on the last day
Brainjock he always does. It’s pretty much expected that the the viewer has some prior knowledge in astrophysics and cosmology as well as quantum... yea, I would just watch as much as you can and over the years you will soak it up if it really interests you.
Brainjock yes, I agree. Vsauce is nice too for more straight forward explanations
What's on the other side of a black hole? Billions and billions of unpaired socks
You fat bloated sack of protoplasam!
38 likes it so far
guitar picks
@@RequiemPoete you ego-wrecked, undisciplined Stryker in the Darkness!
what's on the other side of black hole?
the dark side hhhh 🤣
I can’t wrap my head around this stuff. Glad there’s people that understand physics.
Stay safe Matt. I can't imagine a world without Space Time.
Ba dum, tsssss!!
me neither
Quantum Mechanics forbids this
Pun intended?
@Anirban Chakrabarti Haha, that's a good joke! Can't believe Motor Head didn't think of that one lol
Came in with curiosity
Left with a degree in physics
This channel talks about so many fascinating topics.
Just Some Guy without a Mustache alway feels great to learn something new.
Also you need a moustache your lip will get cold
I blocked u why am i still seeing ur comments
Seriously. I tried physics and astronomy in college and even though I learned a lot it wasn't for me despite how much I adore both of them. I'm focusing on being a psychologist.
This channel allows me to continue learning at a significant rate, it even increases in complexity when you get to things such as the holographic principle. It keeps the mind seriously engaged.
You need to finish advanced Calculus just to take Astrophysics. This is bordering on Science Fiction. Your graduate degree is not in the mail.
I really wish youtube and channel like this were available when I was younger, I would've been much more likely to get into math rather than asking "What am I going to ever use trig for?"
Exactly. We're taught to hate and fear math because it's usually taught in such an ass-backwards manner. If only we were shown at a young age how fascinating it is.
@@mandaJt I was in the 3rd quarter of calculus based physics in college when I realized I was finally learning all the things i desperately wanted to know in grade school but nobody would teach me. And I thought: man, why couldn't they have taught me this back then, I wouldn't have nearly flunked out of middle school before my folks brought the hammer down about studying. And then I realized that all the folks I was helping in the math lab as a tutor were elementary school education majors who could barely pass basic algebra with loads of help, and it all made perfect sense.
Or maybe, blame your government for giving you shitty teachers 👍
Fry: “Are there even more universes?”
Professor: “Nope. Just ours and the Cowboy Hat Universe.”
LMAO
Good News Everyone
Fry from Futurama
@@JamesP5871 I'm still technically alive!
Matt raises an interesting point, there is a substantial lack of penguins on this channel.
club penguin music intensifies
But there are monkeys and other primates. So there's that.
So you want more videos on CP violation?
I'm definitely not a penguin.
Got any fish?
I think he mistook the ducks for pengus
I'm following a course on General Relativity now at university, and for the first time in my life I have watched a PBS Space Time video and understood nearly all of it
This is actually beautiful
This makes no sense. Im feel dumb asf watching this.
Great! Maybe you help me understand something then. Assume you could actually travel at the speed of light in a spaceship, then all distances traveled are experienced as an instantaneous trip for the people in the ship right?
So if you wanted to travel to say, the center of the galaxy, you could calculate and plot your path in space, sure, but how would you know "when" to slow down the ship to arrive at the right point along your trajectory? Is it even possible?
Please keep these episodes up during these crazy times. It really helps to keep learning! Thank you to everyone at PBS!
If space and time swap inside a black hole, in which direction do I see myself spaghettified if I fall into it? - a concerned Italian.
Purple
@@RequiemPoete that's a fairly good answer
would you be able to feel spaghettification? Would you feel nothing because time is still or feel it forever (for lack of a better word)? - a confused Canadian.
Never mind watched a vid.....so much worse then I thought
You've already been spaghettified before crossing the event horizon, so there is no longer a "you" to continue being concerned.
10:22 “it’s okay that this doesn’t make much sense"
oh awesome phew
A bookshelf. Duh.
MURPH!
Best movie
Oh yeh that "accurate" movia
That or it’s the kessel run.
What do you mean? A bookshelf? Like a little girls room bookshelf?
Today is April's fools day
Him: Faster than light travel is impossible
Me: So it is possible
No, its necessary.
with wormholes you could get from point a to point b faster than light
Tachyon are subatomic particles faster than photons / light
Correct, space is expanding at a superluminal speed.
@@DeuceGenius Well, yes, but you would've also traveled back in time, so not really anything wrong there
I started watching Spacetime about a year ago from the first episode. I have finally caught up with the episode that came out when I started. What a brilliant channel! Thank you.
"There once was a fellow named Dark,
Who entered a black hole on a lark
Time became space and space became time
And he compressed to the size of a quark."
-EH
Brilliant!
admirable.
#Limericksforlife
"It's ok that it doesn't make much sense."
Quote of the episode!
Haha
Probably because no one really knows, just conjecture and hyperbole. Do blackholes even exist in our dimension?
@@dobdoa3691 check this article pls; www.researchgate.net/publication/325709903_Are_Black_Holes_Actually_Quark_Stars
This should be the tagline for the whole channel.
@@dobdoa3691 They most definitely do exist.
amazing graphics as well as amazing teaching. enjoyed it very much. one of my most favorite channels across youtube.
Thanks Sir Matt O'Dowd
It's always fun to come here and pretend to understand what he says.
*sigh of relief* ok....I thought it was just me
Same
Glad I'm not the only one
Its not hard to follow what he says bro
Wow this means I'm not alone😌
"There once was a girl named Bright;
Who could travel much faster than light;
She went out one day;
In just such a way;
And returned the previous night."
- Niven
The way I've heard it, the limerick goes something like this...
"There once was a lady named Sprite;
Who could travel much faster than light;
She left one day;
In a relative way;
And returned the previous night."
And if you want to go down a classic rabbit hole, Google "Pretty Poly Nomial" or "Impure Mathematics."
I think we've all either heard or made up slightly different versions of this and most other limmericks, lol. Mine is:
There was a young lady named Bright,
Whose speed was much faster than light.
She went out one day
In a relative way,
And returned the previous night!!
Nice! But maybe she had a jealous sister who tried the same, nevertheless got stuck in vain and now the b*mbo is stuck in limbo?
@@phd1313 luckily Bright warned her not to try that, before her sister had done it, after Bright found.
"I understand all the words and sentences but not the meaning that they convey" - my last bench mate
"... there's no abrupt edge to spacetime flapping in the wind" made me lol
Anybody else picture a bathrobe? "Hey Spacetime! I can see your doodle!"
lol
This is the most satisfying answer to this question I've ever seen
I love watching videos I don't understand a word of. It's kinda calming.
It is great for falling asleep!
Fry: So there are an infinite number of universes?
Professor Farnsworth: No no, just the two.
Until he created that damned box.
@@laurenno8674 we're sandwiched somewhere between alpha and omega (beginning and ending) in this paradoxical deferment we exist in.
@@Buster-im5so No.
Bite my glorious golden ass!
@Science Revolution Found the stoner.
What do we want? Time travel!
When do we want it? It's irrelevant!
I know this is from 5 months ago, but gosh darn that really made me chuckle 😂😂👏🏼
@@catharanne At least we have succeeded in time travel into the future then. lol
@@whoever6458 😋
What do we want? Time travel!
When do we want it? At least 10 minutes before we thought of it
Take it you have been watching terminator.
This guy makes me wanna go back to school and get a degree in physics just so i can understand this.
I wonder why I enjoy listening to this stuff so much when I can’t understand any of it ??!!
Maybe you're hoping that your subconscious can understand it better than your conscious.
The mind has an primal hunger of knowledge and understanding. No matter how much you try to "dumb down" the mind and go through the daily motions.
martytime march well I must be working overtime 🤣
The real question is.....do you accept this as truth even though you don't understand? And if yes...then why?
@DoubleEdgeSword who mentioned religion?
Me: We did it! We made it to another universe!
Warhammer 40k Universe: Immediate high gothic chanting
Me: Uhhhh let's go back!
In college I was always at or near the top of the classes I took. But I wasn't taking physics or very high level math classes. The brain this guy possesses is so much more intelligent than my brain and it's not just him. In my life I've run across a lot of people who are insanely smart. I would say I only understand about 30 percent of what this guy is talking about and the amazing thing is I keep watching and listening anyway.
To me there's always a big difference between people who know how to store information and people who know how to process information. It's ofcourse a plus to be able to remember a lot of info, but what's the use when you can't see the connections
I saw the title and thought, "there's gonna be Penrose diagrams!"
And behold, there were Penrose diagrams. I learned about those from this channel. Thanks!
im always been a pretty smart person then i met people like this in college and realized i was average
mood
I hate being average.
...and...with that in mind, I've also been that "hyperintelligent by comparison" in other environments. Kinda unsettling how little it takes to be considered a functioning adult, with that said.
It’s all about understanding and analysis. Just because one understands more about a specific subject matter does not mean they are more intelligent they you.
@@lukeskywalker4939 Agreed. Also, just because someone can fulfill the tasks which lead to their grade doesn't mean that they have a good understanding of the subject matter. It's frightening how many students now (after a generation of massive standardized testing) expect that a given question has a specifically worded answer rather than being able to work it out from the previously learned material. I.e., logic & critical thinking are quickly disappearing, even among university graduates.
6:03 "If we trace those coordinates to their full extent, we get what we call a "Maximally Extended Schwartzchild Solution."
So, you get a mess
"An inevitable crushing future in which the space around you becomes infinitely curved"
Are singularities the end result of self-isolation?
l SciFSCIFI
ll
To use a worm hole you would have to survive the near infinite density and your atoms being torn back into elementary particles or even some lower levels of time/space/particles we are unaware of. An infinite number of possibilities come from fantasy mathematics beyond the event horizon. The realm of the densest part of a black hole is probably unobtainable in experiments and the real physics of the super dense probably will never be known. Extending what we observe into the area is a logical approach but most likely doesn't come close to the reality of the real black hole.
Matt: _"normal maps are useless"_
Me: ptsd from flat earth arguments
They should know better. It's obviously a truncated octahedron.
It would be pretty flat without a normal map
Yooo
@pyropulse maybe I am
@@discomfort5760 did we obtain OCTAHEDRON of Transcendence?
14:41 "happy little entanglements" - aww, mate :D
Excellent video, as always!
When Matt is starting to have difficulty pronouncing his own text, you know you are about to rewind 10 seconds (or back to the beginning)
well, at least he is trying to pronounce all properly and is improving over time. Not every scientist is english speaking, so you have a lot of german, french, russian, etc scientist as well, after whom are certain things named. so he has a lot of names, that are pronounced very differently, from what you are used to in english.
10:20: "It's okay that this doesn't make much sense." Good, now I don't fee quite as dumb.
We already know what we'd find in a parallel universe: It's like this universe, but Spock has a beard and everybody's evil!
And I'd be rich!
And you have better social skills
I think the other side is the good one 🕜🕜
And Eric Cartman is good.
Don’t forget that PICCCCCCCCAAAARRRRRRD!!!!!! Is Khan’s evil nemesis!
"A Plummeting Cartographer" is going to be the name of my band.
Gay!
Im thinking.. The .Super Lumenals
Mines gonna be "White Hole" lol!
I like The Silent Cartographer too.
Too bad it's not the late 90s early 2000s when some people actually cared about crappy alt rock bands
INTERVIEWER: What's your favorite number?
MATT: 10^some stupidly large number
My favorite number is the square root of TREE[3] ^ graham's number
I always used to think a black hole was an actual hole when I was younger. Then I learned more and believed they was just incredibly dense mass with such gravity even light couldn't escape. Now I'm back to square one
1:56
Matt: A relatively simple bit of math.
Me: *looks at the schwarzschild metric* You have got to be kidding me! That's not simple at all!
Everything is relative in physics.
compared to the math required to get the metric of a regular rotating and non eternal blackhole...
@@Erik-pu4mj Good point.
maybe a joke? humor? anybody?
edit:in not, i am with John!
@@sadderwhiskeymann It's not even pages long. It IS pretty simple, relatively.
A viewer 20 years from now; Why is Matt emphasizing he's alone in his apartment and using hand sanitizer?
You don't want to know... those days of late republic period were highly decadent.
...talking about how entanglement doesn't have to be monogamous.
There is a 50% probability that the observed result is in fact a bottle of lube, you just measured it wrong.
at Herbert Miller -- Does that preclude everyone making web videos (or content) going back to at least the start of Feb 2020 put a disclaimer on every thing they produce?
Or mabye you simply infer that people would be too dumb to correlate the historical events of 2020 and figure it out?
Go search for photos of 1930s era depression lines ...
"Gee, I wonder why all those people are standing in line, must be for concert tickets? No wait .. that sign says 'free food'; must be either 'normal' homeless or a promotion at the restaurant in the picture; couldn't possibly be a national depression, because ya know there was no Internet back then". Based on your comment, I kind of put you in the latter.
PS - Make sure you label your comment so people 20 years from now know WTF you're comment is referencing.
Such an awesome channel with high quality videos!
All have to say, I like that background painting a lot. I Love the colors scheme and contrast.
Just another turtle. It just turtles all the way down. 🐢 🐢🐢🐢🐢...
Whales , there are whales below turtles ...
@@aadipandey8237 No..; Elephants, you tourist...
@@cofa4011 well some way down there are whales too , I m pretty sure abt that.
I love sturgill Simpson
.
These PBS shows are so good, pbs eons, origin of Everything and 2 cents 👌
Maximally Extended Schwartzchild Solution. That acronym can't be an accident
Sharp
I SAID THE SAME THING 🤣🤣🤣
Its a mess
Black holes dont have a back side. They just have an inside.
Thats what I came here for. Thank you
That depends. Are you looking from a 2d/3d/4d perspective? Do you include/exclude the even horizon? Do you include quantum mechanics?
I always love when you guys say "faster than light travel is impossible" and I'm just here like 👌😌 sure bro, you'll see.
I’m wondering how seriously we should take the idea of just extending maps to see what they look like. In sticking with the comparison to maps of earth, I can imagine someone saying “the lines converge at the north and south poles, so if we extend the lines, we can see that there’s mirror reversed earths stuck to the north and south poles, as the longitudes diverge again.”
My thoughts exactly. Penrose diagrams are just a model that fit our observations of the universe. They are not a rule book that the universe follows and it’s quite possible that the penrose diagram would simply not work when trying to explain what happens when you cross the event
horizon
a "Maximally Extended Schwarzchild Solution", eh? a right old MESS indeed
you keep doing whatever it is that you are doing :)
Three hours have passed, endless science questions queried, and for each, you sir have had a video. Kudos.
just backwards long jump multiple times and you'll end up in a parallel universe
Yih! Yih! Yih! Yi-yi-yi-yi-yi-yi-yi-yi-yi-yi-yi-yi-yihoo!
Is that mario 64 reference?
Wow
@@CyberSage796 speedrunner mario vs melee fox by TerminalMontage
This actually works
Question: According to the theory of Hawking Radiation, a black hole may eventually evaporate away (in a very very long time) right? In addition, when one is falling into a black hole, time slows down for them and they see the universe behind them with its time accelerated faster and faster. My question is, that is it possible that the black hole would dissolve before the person reaches the singularity?
I might be wrong in most of what i said lol
This was answered in a previous video about black holes, you don't actually see the universe in fastforward when passing the event horizon because your past light cone does not cover that part of the diagram.
Or at least that's what i understood of it.
The black hole bleeds energy ergo mass via this radiation. If it looses enough energy, shouldn't it cease to be dense enough to be a black hole? Or does it shrink in diameter?
I was wondering myself. Apparently, regarding the universe, you wouldn't see it accelerate unless you fire your rockets in order to slow down your fall and try to race away at near light speed. If you instead stay in free-fall, you will see the universe at a normal pace.
Regarding the Hawking radiation, I found this: physics.stackexchange.com/questions/22498/from-where-in-space-time-does-hawking-radiation-originate.
The diagram on the site shows an evaporating black hole, and apparently the horizon is at an 45 degree angle even in that case. That suggests that once you're in, you're doomed as usual. It's far from clear to me what happens to spacetime at the point where the black hole evaporates though.
Maybe a good topic to ask for a future video? :)
simply think of the person as a bunch of particles.
Just found out this video, that I can watch it in 2160p. I am astounded. It looks.... amazing!
What if the "edge" of the universe was an inside-out black hole, or at least acted as such? Imagine a flat plane that only seems to stretch out infinitely, but if you were to zoom out enough you'd see the edges start to curve downward until they drop off straight downwards infinitely, just like the flat plane representation of a black hole. The resulting diagram would be shaped like a really big cylinder. I've watched so many of these I can't recall if this idea has already been thought up or not, but i thought I'd bring it up anyways bc i think its an interesting alternative idea to what the "edge" could be
By an "inside out black hole" do you refer to a white hole? Because if the "edge" of our universe were that, it would emit a lot of light and repel things from it with great force. Not only does that go against all the findings of the nature of the expansion of the universe, which is going outwards not inwards, but it also would likely negate effects we see like red-shifting and Hawkings background radiation. If the edge of our universe was specifically something that emit a great deal of light and gravitational force, I imagine that would be observable at some point when you get those star images where you can zoom into darkness and it reveals hundred of millions of stars packed together. I think a more accurate image of our universe would be a shape we can't physically imagine because all of its sides would be connecting to the opposite side, sort of akin to a sphere, but if at any given point on the sphere it connected to the point directly opposite of it on the other side of the sphere. The Universe very specifically does not have any sort of edge, and the PBS guy specifically mentions that being a bit of a problem in interpreting the flat plane representation of our universe. Just like how things get disproportional on the map of Earth, the Universe map is disproportional because it's intentionally putting an "end" on things that are infinite.
@@tanner.mackey.mp3 No i wasnt thinking quite like a white hole.... I was just imagining a spherical boundary (assuming one can be assigned) around the universe that acted similar to a black hole, in that it attracts matter in some way as an alternative way of explaining why intergalactic space is expanding faster than we think it should be. Idk, in hindsight it probably doesnt make too much sense now, honestly just trying to think creatively to keep my brain from rotting in quarantine lol
Its a wall of fire.....
Read my comment. I think it is aligned with yours in a way. And has nothing to with what the scientists say.
Trust me...your as right as they are.
Start of video: "Normal maps are useless..."
CGI artist: *angrily closes video and unsubscribes*
why? in CGI you can make anything, so if anything they will be excited. Noob.
Then he starts dissing stretching in UV maps.
@@momoproblems0 You didn't understand the reference.
This made so much sense that I had to watch it twice
6:10
So, we're just not talking about how Maximally Extended Schwartzchild Solution reduces down to M.E.S.S.?
that totally needs to be an official acronym.
Is the word "mess" in some way an apt term for it? If not, there's no sound reason to make the acronym. It's this same misguided thinking that leads to stuff like "G.O.A.T.", whose connotation is pretty much the opposite of what that "term" means.
Dr_Owen Maestro
I uh, I think you missed the joke.
@@Chad_Thundercock Ok, let's dig in here. What's the "joke" I missed?
Dr_Owen Maestro
To the casual chap, to "expand an equation" is to annotate every part of a shorthand variable. An example might be to write '9.8 m/sec/sec' instead of the much simpler notation 'g'.
So a maximally expanded equation would seem, to someone not well versed in the math of such complex physics, to be quite a mess of numbers.
Of course, finding humor in such things is always subjective. Humor or distaste, your perspective is as valid as anyone else's, and I appreciate you helping us drive the engagement algorithm for this great series.
PBS: Normal maps are useless inside black holes.
me, cg artist: cries
Thank you for sharing this video that was very powerful. I really enjoyed it. Well presented.
Imagine Christopher Nolan turning this into a movie.... Interstellar Dos: Los Nero Wholas???
Never fails. Watching these videos humbles me every time.
Was this super simplified? Still can't understand it, but I loved it.
First part of the video: It's another universe!
Second part: Haha jk same universe
Sooo that’s where Matthew mcconaughey went to see his own daughter in the parallel universe. Jk I have no idea what happened in that movie
It's simple. He goes into the black hole, some timey whimy wibbly wobbly stuff happens, he sends a text message to his daughter through Morse code through a watch, some more timey whimy wibbly wobbly stuff happens, he gets spit out of the black hole.
The End.
PS
I don't know how to spell whimey.
Dan Kuchar maybe "whimey" with an E. "Whimy" would be related to a "whim" and we're looking for more of a "whime". Feel da whithym, feel da whime, come on Jamaica, it's bobsled time!
@@TheBRad704 wouldn't it be "bobswed"?
@@TheBRad704 Very funny Cool Runnings
He fell into a structure that future humans will build and hide inside the event horizon of a black hole. That structure kept him from dying in the singularity and let him travel freely in the time dimension to find the perfect time to send a message to his daughter.
If space is infinite, doesn't that suggest that any "parallel" universe, is really the same universe as one parallel to it? If the universe is infinite, surely you would never be able to tell if you were in a "different" universe.
Listening to Matts lectures is a bit like a Penrose diagram, everything is going fine then suddenly everything goes off in a tangent and im like by by 👋 aint got clue
This guy could literally tell me anything and I'd believe him
You're supposed to think! Not be a sheep.
@@jovetj what's wrong with 🐑? They help me sleep
@@sting0072007 Everything
@@sting0072007 They help you sleep? Without a peep?
@KC I think they're being sarcastic
This channel needs a cliff notes or A for dummies section. I completely understand other people when they talk about this stuff. For the most part. I come here and quickly realize... I never know what they’re saying at all lmao
1:58 "Relatively simple"
lol
it is indeed simple relative to more complicated math
Way over my head! Too hard to comprehend, just like what was before the big bang!!!
I'm just glad that it doesn't end at our universe and continues into a next
I'm like Towelie, i have no idea what's going on.
Stop getting high.
Jovet yes weed is why Carl Sagan was so dumb. Wait what?
Wanna get hiiiiiiggggghhhh?
_"Time appears to freeze"_
- there must be an Event Horizon at my front door whenever I return without having told my wife I'd be late...
i feel you! esp if you're talking about the jealous type.
I guess you shouldnt have cheated and broken her trust or something?
With a Supermassive singularity Stick in her hand.
Wow
Quite clearly. There isn't going back
Mega well explained great graphics thank u
7:55 Why do all other sources say the Einstein Rosen Bridge exits to the top of the diagram into a white hole (the singularity replaced by a bridge) rather than to the side, and does not require superluminal travel? I think you even do in your white hole episode. Totally confused now.
They are both valid. The one requires passing through the singularity and emerging out of a white hole into a different parallel universe. This one skips the (probably) certain death of the singularity and instead escape out of the black hole into a parallel universe.
cmilkau This video only looked at going through event horizons, which involves superluminal velocities and takes you from an area of normal spacetime through an area of warped spacetime into an area of normal spacetime. Things dealing with wormholes tend to look at traveling in to a singularity in the centre of warped spacetime and then traveling away from the singularity, which is a 90 degree offset to the theoretical universe to universe examples in this video. It just depends on what direction you’re traveling in the Penrose diagram.
@@kylelochlann5053 Never heard if that one either, interesting. The X being a coordinate singularity, though (you are infinitely far in space or time from everything definite), I think everything could be there. Or nothing. You could have a big bang with a primordial black hole infinitely in the past and it would still look pretty much like this.
@@ToddSkelton I don't think there is a parallel universe in this diagram, at least if you remember that three spatial dimensions are collapsed into one. A sphere in a 1-dimensional space are two points. Add time, you get two lines, that is the big X in the diagram. In 2-D, however, you get a double cone, and its exterior is connected. Basically this just says you can walk around a 2D black hole, there is no other side. Now in 3d, it's much the same as in 2d, you just have more choices to walk around a ball than a disc, but other than that, there is still just one universe.
Happy April fools' day -_-
I would love to see a Star Trek movie that explores these questions.
You are great at explaining the science of the universe !!!! 👏👏👏❤️
Scott Manley did a visual representation of a wormhole its a good watch to follow this one
Coldsnap Link: ua-cam.com/video/V7e-1bRpweo/v-deo.html
Thanks for the reminder.
Thanks to both you guys for the mention and the link. It's mindblowing lol
Was it this show, or was it "Infinite Series" that did a big series on the Penrose diagrams.... I think minute physics also did something.
I miss Infinite Series
This one did.
I miss Infinite Series, too.
This one has a good few vids on it
@@PopeGoliath We all do, Scott. We all do.
Gayyy
Wow, this is at a new level, I obviously have some serious craming to get done ....
10:20 “...which is very confusing.” Right. It all made perfect sense until then. :)
You watched Tenet so you got the explanation now xD
I’m always fascinated about how much we know about the universe and only 5 percent about the seas and oceans here on Earth
Last time I was this early, inflation hadn't happened yet
The Simpsons already showed us what’s on the other side of the singularity. It’s just a dumpster outside of an erotic cake shop. #fatair
Haha
Easy equation Simpsons = culturally irrelevant. Sad to tell you that, todays cultural hotspots for relevant pop cultur in the animated tv realm lays in Southpark.
Doesn't matter what's on the other side.... It's surviving the trip through that's the real trick! 😯
Clicked as soon as I saw the title.
14:55 Matt breaking out his lube and dead eyeing the camera 💦
Baraldi works done, time for fun?
Surprise fact: The cameraman was actually a woman.
LMAOOOO IM DEAD BRO
Head canon accepted
Falling into a Black Hole = Universe puts you in Time Out.
Interesting topic... Thank you PBS
The part near the end reminded me of how travel between the two universes occurred in Fringe. To travel between the universes two objects paralleling eachothers mass needed to be simultaneously ejected into the other's universe preserving the balance of matter between both universes. In this sense, a black hole / white hole would act as the equal sign in what was, for lack of a better term, a massive universe sized equation in which the law of preservation is able to be maintained. From the perspective of the traveler they bridge the gap between the two universes and emerge out on the other side but from the perspective of observers in the two universes the individual would parabolically approach the black hole only to suddenly reverse course and emerge back from it. The show never quite used black holes to do the traversal but instead used pseudoscience and later on in the series psychic mind power induced woo to achieve the exchange. But in a more real world scenario the exchange of matter might make sense up until the point where the shift in angular momentum occurs. At the bottom point of the parabolic curve where the two items of equal mass exchange their universal coordinates, the exchange would hit the same roadblock of approaching infinite time unless FTL or other yet to be discovered methods of solving the equation / bridging the equal sign are involved.
The image of the traversal of the singularity via FTL means appearing to be a reversal of time reminded me somewhat of the show so I figured I'd share. Not a physicist, just watch a lot of these videos as a hobby, so apologize if my understanding is way off, lol!
Yeah, I was going to point out the exchange of matter isn't really happening between black holes and white holes in a back and forth sort of way. At the very core of our understanding of black holes, they take IN matter and light and condense it nearly infinitely to create a singularity at the center of the black hole. White holes have never been observed and are purely speculation at this point. If a white hole exists, it would be the only version of the two that things would be coming out of. Like the guy said in the video, if an object or photon goes past the event horizon of a black hole, it is NOT coming back. An outside observer would watch it shift colors and slowly fade, and an observer inside the event horizon would observe the object get spagettified and compressed until it became part of the singularity itself. So the whole exchange you're talking about wouldn't be possible without two black holes and two white holes, and then some (currently impossible) means of communicating between the two universes.
Also, the universe itself doesn't seem to care a whole lot about the balance of matter versus anti-matter. It's only independent matter itself that can't be created or destroyed. If matter were to enter into our universe from some portal from another universe or whatever, our universe would almost certainly be indifferent to it.
Wow! Thanks for the thorough clarification. I am grateful for your time in explaining it to me and not calling me out on my layman's understanding of how this stuff works. Some people can be total pricks about stuff like this, but you were very kind to take the time to explain it nicely. Wish more people on the internet were like you ;-)
@@tinyguy9398 hey man I'm always happy to help spread knowledge, and I appreciate your appreciation lol. Some people get really hostile when I try to explain something they seem to misunderstand, so I'm also glad you were graceful in receiving my information.
Most interesting presentation. Thank you.
So if Termina really is, in the Penrose sense, the parallel to Hyrule, then that "portal" in the Lost Woods really is exactly that. No wonder the Hero of Time was away when the Hylian Alliance could've used him during the war against the Gerudo after his defeat of Ganon in Ocarina of Time. By the time he returned after ridding Majora's Mask of its evil, Ganondorf had already been banished to the twilight realm at the expense of one of the sages. Fast forward to the events of Twilight Princess, where the master plan set by the Hero succeeds and Ganondorf is killed for good, only to later be reincarnated per the curse placed on the Heroes by Demise. That portal may also be the reason the Zelda adult timeline didn't have a hero until the Hero of Winds (not even of the Hero of Time's own bloodline, unlike the Hero of Twilight) showed up and killed Ganondorf almost the same way the Hero of Twilight did. So "Hero of Time" is even more fitting a moniker now!
Gay
I like you
@@RustyShackelford6 We all know that you are don't have to announce it
I think about Zelda lore all the time. It's quite complicated.
Playing too much with coordinates will get you into a fictional universe, coordinates are not physical don't take them to seriously
Hey I just took a Mercator map of the Earth and extended it upwards. Now there's a lot of new space to the north of the north pole!
The dimensions are the key.
they are physical. We use them to map our location on Earth, in our solar system, in our galaxy. Spacial and temporal coordinates represent the four dimensions we have freedom to move in, with time being just as real as the spacial ones. We require four coodinates to describe our location at any given time. sometimes we can get away with just two coodinates on earth as a two D position of longitude and lattitude, if time is not needed The coodinates are just the measuring rod of the dimensions, be it distance or duration. As an example of how all four coodinates are required to precisely give our location at our given time, and an example where the time coordinate is essential, Imagine, if you will, two separate locations - a point "A" and a point "B" - connected by a path. Imagine that you have one person who starts at A while the other starts at B, and they each travel towards the other point. You can visualize where each one is by placing a finger from each hand at A and B, and then "walking" them towards their respective destinations. There's no way for the person starting at A to get to B without passing by the other person, and there's no way the person starting at B can get to A without passing the first person.
In other words, in order for each person to arrive at their destination, there will need to be a moment where each of your two fingers occupy the same spot at the same time. In relativity, this is known as a simultaneous event: where all the space and time coordinates of two different physical objects overlap. This is not only non-controversial, it's mathematically provable. This thought experiment explains why time needs to be considered as a dimension that we move through, just as surely as our spatial dimensions are dimensions that we move through. And the coordinates X Y Z and T mark our position spatially and temporally in dour D space-time. Just as surely as coordinates map our two D location on Earth. Be sure to consider coordinates as physical when you use a satellite phone to call in for emergency rescue if you ever get stranded with hypoxia while climbing a very high mountain. . It wasn't Einstein, however, who put space and time dimensions together into a singular formulation that left them inextricable. Instead, it was Einstein's former professor - Hermann Minkowski - who figured out how inseparable these two entities were., which gives rise to us requiring four coordinates to describe our location.
Less than three years after Einstein first introduced his Special theory of Relativity, Minkowski demonstrated their unity with a brilliant line of reasoning. If you wish to move through space, you cannot do it instantaneously; you have to move from where you are right now to another spatial location, where you'll only arrive at some point in the future. If you're here now, you cannot be elsewhere at this same moment, you can only get there later. Moving through space requires you to move through time, too.
If time weren't a dimension, a coordinates, with the exact properties it possesses, special relativity would be invalid, and we could not construct spacetime to describe our Universe. We need time to be a dimension inextricable from space for physics to work the way it does. and x y z and t coordinates are very real. Demonstrably so both mathematically and in real life.Plus even the most extreme mathematical calculus and algebra of general relativity turned out to be real phenomena-e.g. black holes. So maths, coordinates e.c.t. these numbers are not abstract imaginary numbers, they describe real things. Maths describes reality.