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What's a Tesseract? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Jorge, if you could have just one of the
0:11
Speaker 1: Infinity Stones from the Avengers, which one would you pick? Oh? Man,
0:15
Speaker 1: there's five good choices, but I think the obvious one
0:19
Speaker 1: is the Time Stone. Oh yeah, why is that too?
0:21
Speaker 1: You'd have more time to nap or avoid missing deadlines then,
0:26
Speaker 1: and you could also go back in time and get
0:28
Speaker 1: the other stones. Very clever. It's like wishing for more wishes. Well,
0:33
Speaker 1: I would probably take the reality Stone. You're not happy
0:37
Speaker 1: with our current reality now. I'm feeling kind of tied
0:40
Speaker 1: down by all these physical laws. I want to break
0:43
Speaker 1: one or two of them. And that doesn't make me
0:45
Speaker 1: feel comfortable about giving billions of dollars to physicists. You
0:48
Speaker 1: don't want to watch the TV show called Physicists Gone
0:51
Speaker 1: Wild as long as nobody takes their shirts off. I
1:09
Speaker 1: am more handmade cartoonists and the creator of PhD comics. Hi,
1:12
Speaker 1: I'm Daniel. I'm a particle physicist, and I go wild
1:16
Speaker 1: for crazy particle physics discoveries. Oh nice, what does that mean?
1:20
Speaker 1: You let your hair grow out, you sleep out in
1:23
Speaker 1: nature or at the collider. Well, you know, I've only
1:25
Speaker 1: been in this field for twentysomething years, and in those
1:29
Speaker 1: two plus decades, we've basically only had one discovery, which
1:33
Speaker 1: was the Higgs boson. So that's really the only place
1:36
Speaker 1: I can refer to. And Yeah, we had a lot
1:38
Speaker 1: of parties. We drank a lot of nice champagne. We
1:40
Speaker 1: had a lot of French cheese. It was wow. Nobody
1:44
Speaker 1: picked their shirts off now that I can remember, well,
1:48
Speaker 1: Welcome to our podcast, Daniel and Jorge Explain the Universe,
1:51
Speaker 1: a production of I Heart Radio in which we celebrate
1:54
Speaker 1: all the crazy, wacky, wild stuff about the universe. The
1:58
Speaker 1: things that we don't understand going on in the hearts
2:00
Speaker 1: of black holes, to the things we think we might
2:02
Speaker 1: be grappling with on the quantum mechanical scale, Everything that
2:06
Speaker 1: you want to know about the universe, everything you didn't
2:09
Speaker 1: know that you wanted to know about the universe. We
2:11
Speaker 1: talk about all of it, and we explain all of
2:13
Speaker 1: it to you because it is a pretty fascinating universe.
2:16
Speaker 1: There's a lot going on out there and a lot
2:18
Speaker 1: for us to discover and also a lot for us
2:21
Speaker 1: to imagine happening. Absolutely, and it's fun to think about
2:24
Speaker 1: how the universe might work in different ways. Does it
2:27
Speaker 1: work the way we expect or is life here on
2:29
Speaker 1: Earth kind of unusual and weird, and if we could
2:32
Speaker 1: go to other places in the universe, we might see
2:34
Speaker 1: things working very differently and learned some deeper truth about
2:37
Speaker 1: the nature of the universe and reality. Yeah, unfortunately we
2:40
Speaker 1: have here in our human species, in our human society,
2:43
Speaker 1: we have awesome writers and artists who can imagine some
2:47
Speaker 1: of these things for us, and sometimes that spills over
2:49
Speaker 1: into reality. That's right. Sometimes art and literature and science
2:54
Speaker 1: actually connect and we can explore these fun concepts about
2:58
Speaker 1: the basic nature of space and time and how our
3:01
Speaker 1: universe works in lots of different fund ways, including superhero movies. Yeah,
3:05
Speaker 1: you know, I feel like something there are topics in
3:08
Speaker 1: these science fiction or fantasy or superhero movies that sort
3:12
Speaker 1: of feel like they could be real, but you're not sure.
3:14
Speaker 1: At least it looks pretty real in the movie. It does.
3:18
Speaker 1: And I know that Martin Scorsese is not a fan
3:20
Speaker 1: of superhero movies, but I like that they bring up
3:23
Speaker 1: a lot of these scientific elements. You know, I never
3:25
Speaker 1: saw Martin Scorsese movie bring up fundamental questions of the
3:28
Speaker 1: nature of space and time. There are some place concepts
3:31
Speaker 1: in fantasy and science fiction movies and superhero movies that
3:34
Speaker 1: you know, sound very techy and science and you sort
3:37
Speaker 1: of wonder if they are actually real things exactly in
3:41
Speaker 1: our goal on this podcast is not just to explain
3:44
Speaker 1: what scientists are thinking, but to dig deep into what
3:47
Speaker 1: you are thinking, to answer your questions about the nature
3:50
Speaker 1: of the universe, and explain to you things you might
3:53
Speaker 1: have heard about and wanted broken down. So to be
3:56
Speaker 1: on the podcast, we'll be asking the question what is
4:03
Speaker 1: a test iract now, Daniel, is it test irat or
4:07
Speaker 1: test rat or I think it's test i act? I said,
4:12
Speaker 1: you got you gotta say with some drama, some enthusiasm. Yeah.
4:19
Speaker 1: This is a concept that comes up in a couple
4:21
Speaker 1: of interesting places like the Avengers movies. It was one
4:24
Speaker 1: of the things that they were fighting about and trying
4:26
Speaker 1: to control, and also in the Wrinkle in Time Blox
4:30
Speaker 1: and wasn't it also in that movie Interstellar? Everything was
4:33
Speaker 1: an interstellar Man that was just like a garbage can
4:35
Speaker 1: of all the ideas that everybody had. Man, I was
4:40
Speaker 1: a pretty negative assessment there. Well, you know, time is
4:45
Speaker 1: love and you can move through the fifth dimension if
4:47
Speaker 1: you believe in love. Like, I don't even know what
4:49
Speaker 1: that was Obviously you're not paying attention, Daniel. Love is
4:52
Speaker 1: the fifth dimension? I love the fifth dimension? Is that
4:55
Speaker 1: what that means? And I think you to watch it again?
5:00
Speaker 1: And you know, I think I'm not smart enough to
5:02
Speaker 1: understand that movie. That's really the problem. That's Christopher Nolan
5:05
Speaker 1: movie for you. You need like a PhD or something.
5:08
Speaker 1: I need like seven peachd's like Brince Banner. M there
5:12
Speaker 1: you go back to the Avengers, all right, Yeah, the
5:15
Speaker 1: test arrect shows up in the Avengers movies. And so
5:17
Speaker 1: this actually came from one of our listeners. They posted
5:20
Speaker 1: a question to us. That's right. This is a concept
5:23
Speaker 1: that one of our listeners had heard all about and
5:25
Speaker 1: wanted broken down. So if you have a question you
5:28
Speaker 1: hear about in science that you'd like explained, please send
5:31
Speaker 1: it to us. We'd love to hear from you and
5:33
Speaker 1: love to help you understand these concepts. So here's the
5:37
Speaker 1: question from Zoe from Vietnam. Hi, Daniel, and hell, hey,
5:41
Speaker 1: I'm a big fan of your podcast. Um. I used
5:44
Speaker 1: to dislike physics in high school, but your podcast has
5:47
Speaker 1: now made me realize how funny and interesting physics can be.
5:52
Speaker 1: I've recently been introduced to the concept of a test arrect,
5:56
Speaker 1: and I was just wondering if you could make a
5:58
Speaker 1: podcast episode about how a test ract describes a four
6:01
Speaker 1: dimensional space, is the fourth dimension time and does the
6:06
Speaker 1: testrect relate to the concept of space time? Thank you?
6:09
Speaker 1: All right? Thank you? Zoe? When if she's seen the
6:12
Speaker 1: Avengers movies. They made it out there to Vietnam, didn't
6:15
Speaker 1: they They're everywhere. Yeah, it's an interesting question, and it's
6:19
Speaker 1: one that we were wondering. How many people out there
6:21
Speaker 1: had an idea about what this could be exactly. So
6:23
Speaker 1: we asked our other listeners questions from Zoe the listener,
6:27
Speaker 1: and so basically we're not even needed anymore. The listeners
6:30
Speaker 1: are asking questions and answering questions. Yeah, we're just here
6:33
Speaker 1: to provide the bad jokes and the Wikipedia reading no,
6:37
Speaker 1: and to make everybody realize that physics is awesome. That
6:39
Speaker 1: was my favorite moment in her question, that we have
6:42
Speaker 1: made physics fun for her awesome. So Daniel went out
6:45
Speaker 1: there and asked people and here's what they had to say.
6:48
Speaker 1: I think the test wractor is the four dimensional cube, right,
6:51
Speaker 1: have you seen that? Like my mind has the animation
6:53
Speaker 1: like the cube turning itself inside out. It's supposed to
6:56
Speaker 1: be like a visual aid to help you think about
6:58
Speaker 1: the fourth dimension. Never saw tessellation. Tessellate could be could
7:04
Speaker 1: be same route word. Yeah, I've heard of that before
7:07
Speaker 1: as being a fourth dimensional more model of a cube
7:12
Speaker 1: which acts in the three dimensions, And I've also seen
7:17
Speaker 1: an animation which shows how it behaves. But it's a
7:22
Speaker 1: little bit over my head how that works a fold
7:27
Speaker 1: in space, and apparently to make one you just have
7:31
Speaker 1: to think really hard about it. Testarunt is something super cube,
7:39
Speaker 1: like four dimensional cube, but I know it's something more
7:44
Speaker 1: than that. I don't know more. I don't know what
7:48
Speaker 1: test rings are in physics. When I remember the Avengers movie,
7:51
Speaker 1: they were like blue cubes that had like a lot
7:53
Speaker 1: of energy, So it might be something relating to energy.
7:56
Speaker 1: I remember hearing about it in the movies. A lot
7:59
Speaker 1: I don't remember, but I think it's something to do
8:02
Speaker 1: with like either time travel or bending space. All right, See,
8:09
Speaker 1: a lot of people had heard about it from the movies, Yeah, exactly,
8:11
Speaker 1: the Avengers. That's definitely made this idea, or at least
8:14
Speaker 1: this word popular, And according to them, it's a blue
8:18
Speaker 1: cube with a lot of energy. Yeah, a lot of
8:22
Speaker 1: power in it, somehow mysterious power. Why is mysterious stuff
8:26
Speaker 1: in the movie is always glowing blue? You know, it's
8:28
Speaker 1: like blue some special thing for our brains. It means
8:31
Speaker 1: like weird and unnatural. M Sometimes it's purple. Yeah, the
8:36
Speaker 1: Infinity Stones all had different colors. They're all mysterious and powerful.
8:39
Speaker 1: That's true. And you know, it turns out the Infinity
8:41
Speaker 1: Stones all used to have different colors like in the
8:44
Speaker 1: original comic books. And there's like a reboot, but they
8:46
Speaker 1: swapped all the colors. No kidding, Yeah, exactly. Maybe they
8:50
Speaker 1: used the Reality Stone, dude, with the colors. I come
8:54
Speaker 1: from an alternate universe where the Reality Stone was always purple.
8:58
Speaker 1: What It's all going towards the multiverse apparently. So that's alright,
9:03
Speaker 1: So break it down for us. What is a test react? Tests?
9:05
Speaker 1: React a super fun concept. It starts in geometry, where
9:10
Speaker 1: it's basically the fourth dimensional extrapolation of what a cube
9:15
Speaker 1: would be in three D. But it really does have
9:18
Speaker 1: deep connections to like the nature of space and space time,
9:21
Speaker 1: and then of course it does appear in science fiction.
9:24
Speaker 1: But at the root of it, it really is a
9:26
Speaker 1: geometrical object. Take a cube, which is a three D object,
9:31
Speaker 1: and try to imagine with the four D version of
9:33
Speaker 1: that would be that's a tests react M. You mean,
9:37
Speaker 1: like you know, length with depth would be three dimensions,
9:41
Speaker 1: And like what if you added a fourth one? Yeah, exactly.
9:44
Speaker 1: You start with a point to which is zero D.
9:46
Speaker 1: You make a line which is one D. Then you
9:48
Speaker 1: add the second dimension. You get a plane. You had
9:50
Speaker 1: a third dimension, you get a cube. A tessaract is
9:53
Speaker 1: what happens if you add a fourth dimension? M M.
9:56
Speaker 1: I see. And it has to be like a dimension
9:58
Speaker 1: in space, like could it be like a density? Could
10:01
Speaker 1: that be something or I don't know color. That's a
10:05
Speaker 1: cool idea, you know. Mathematically it doesn't have to be
10:08
Speaker 1: connected to anything physical in geometry. These are just you know,
10:11
Speaker 1: points in some arbitrary space. But by space they don't
10:15
Speaker 1: necessarily mean like physical space. It could be space, it
10:18
Speaker 1: could be time, it could be anything else really, and
10:21
Speaker 1: so mathematically it's just sort of like an abstract concept.
10:24
Speaker 1: It's like a relationship between points. It's the definition of
10:27
Speaker 1: like the number of ways you can move around in
10:30
Speaker 1: that space. I see. So, but mostly people think of
10:34
Speaker 1: it as sort of like something you can move around in, right,
10:37
Speaker 1: like you can't. It's hard to move around color or
10:40
Speaker 1: or density. You can map it dimension anything. Yeah, you
10:43
Speaker 1: could map it to color, you could map into density. Really,
10:46
Speaker 1: you take this abstract concept of a dimension and map
10:50
Speaker 1: into something physical basically anything you Like, The question is
10:53
Speaker 1: does that really mean anything? Like is there anything in
10:56
Speaker 1: our universe which really respects that as a dimension or
10:59
Speaker 1: refle lets that as a dimension. That's why, for example,
11:02
Speaker 1: and we'll dig into this later, why we think space
11:04
Speaker 1: and time might fit together into four dimensions because there
11:07
Speaker 1: are real physical things about our universe that reflect and
11:10
Speaker 1: respect that dimensionality. But you can make up your own
11:13
Speaker 1: dimensions doesn't necessarily mean anything. M So it has more
11:17
Speaker 1: to do with like a coordinate system, right, Like if
11:19
Speaker 1: you have a coordinate system like x, y and z,
11:22
Speaker 1: what happens if you add another one like double a
11:24
Speaker 1: or something? Yeah, or you go backwards you had W right,
11:27
Speaker 1: So like W X, y and z. And this is
11:30
Speaker 1: tricky to think about because we're used to thinking in
11:33
Speaker 1: three D, because they're you still living in three D.
11:36
Speaker 1: So you might be trying to imagine in your head, like, well,
11:38
Speaker 1: what is a four dimensional version of a cube? Look
11:41
Speaker 1: like it's not hard to imagine a point or a line,
11:44
Speaker 1: or a plane or even a cube. How do you
11:47
Speaker 1: like play the mental game of imagining a four D cube?
11:50
Speaker 1: What does it tests aract, look like other than like
11:52
Speaker 1: a blue glowing cube on the screen at the movie theater.
11:55
Speaker 1: I see, So it's a geometric shape basically, but it's
11:58
Speaker 1: a geometric shape in four dimensions, exactly in four dimensions,
12:02
Speaker 1: and we can play games trying to imagine what it
12:05
Speaker 1: might look like. Obviously, we can't like build something in
12:08
Speaker 1: four dimensional space because we think we live in three
12:10
Speaker 1: dimensional space, But that doesn't mean you can't like play
12:13
Speaker 1: some games to help yourself understand it. Like, you know,
12:15
Speaker 1: you can look at the drawing of a cube. Drawing
12:18
Speaker 1: is usually in two D. You write on pencil on
12:20
Speaker 1: paper that's on a plane, but you can draw the
12:23
Speaker 1: lines in a way that your brain looks at them
12:25
Speaker 1: and imagines a three D object in your three D
12:28
Speaker 1: mental space. You can do sort of similar stuff drawing
12:31
Speaker 1: things in three D or even in two D to
12:33
Speaker 1: give yourself the impression of what a four D object
12:36
Speaker 1: might look like in your mind. M M, I see,
12:39
Speaker 1: Like you draw a cube, and you you draw another cube,
12:42
Speaker 1: and you connect them together somehow. Yeah, exactly, you can extrapolate, like,
12:45
Speaker 1: how do you draw a three D cube on a
12:48
Speaker 1: two D piece of paper? When you take two squares
12:51
Speaker 1: and you connect all their edges, then it looks like
12:53
Speaker 1: a cube. Right, So if you want to play the
12:56
Speaker 1: same game, now draw two cubes piece of paper and
12:59
Speaker 1: can act all of their eight edges, And that's sort
13:03
Speaker 1: of maybe what it tests rack might look like if
13:06
Speaker 1: you were four D being with four D eyes and
13:08
Speaker 1: a four D brain. M right, But I guess that's
13:11
Speaker 1: just sort of like a a drawing or a or
13:14
Speaker 1: like a spatial way to depicnic But really, I mean
13:17
Speaker 1: if there was a fourth dimension, you wouldn't see it
13:19
Speaker 1: in our three dimensions, right, Yeah, that's a great question.
13:22
Speaker 1: I mean you would see it, but you would only
13:24
Speaker 1: see a slice of it. Right. The fourth dimension, if
13:27
Speaker 1: it was a real part of space and time, wouldn't
13:30
Speaker 1: be something hidden to us. It would just be that
13:32
Speaker 1: we couldn't see all of it. You know, imagine being
13:35
Speaker 1: a two D being in a three D space. You're
13:38
Speaker 1: still seeing that three D space, You're only seeing a
13:41
Speaker 1: two D slice of it though, So things would look
13:43
Speaker 1: pretty weird if we were in a four dimensional space
13:46
Speaker 1: and we were three D beings. All right, Well, maybe
13:50
Speaker 1: let's jump into this idea of a fourth dimension. What
13:53
Speaker 1: does that even mean, Daniel? It's hard to wrap your
13:56
Speaker 1: mind around because our brains are three D objects and
13:59
Speaker 1: we've been thinking about three dimensions for so long. And
14:02
Speaker 1: you know, if you think about X, Y and Z,
14:06
Speaker 1: those are like three glowing lines in your brain that
14:09
Speaker 1: are all ninety degrees from each other. It seems like
14:12
Speaker 1: they sort of fill the universe. The whole idea behind X,
14:15
Speaker 1: Y and Z is that that's all you need to
14:17
Speaker 1: know to know where anything is. Like with if you
14:20
Speaker 1: specify the X, the Y, and the z value, then
14:23
Speaker 1: you know where something is. There's isn't the need for
14:26
Speaker 1: another direction, But now try to add a fourth dimension,
14:29
Speaker 1: Like where does it fit? You can't stick another line
14:32
Speaker 1: coming out of that axis because it would be moving
14:35
Speaker 1: through three D space. So you have to like take
14:37
Speaker 1: this sort of mental leap and imagine a whole other direction.
14:41
Speaker 1: So imagine like a family of these X, Y, Z
14:44
Speaker 1: axes and the relationship between those is the fourth dimension.
14:48
Speaker 1: So you can move from like one access to another
14:50
Speaker 1: access to another access. That's motion in this now other direction, right,
14:55
Speaker 1: and I think that maybe the interesting thing, or the
14:57
Speaker 1: tricky thing to imagine is that moving in this other
15:00
Speaker 1: fourth dimension shouldn't affect how you look like in the
15:04
Speaker 1: original three dimensions. Right, Like I can move backwards, forwards,
15:08
Speaker 1: up and down into the sides in our regular three dimensions.
15:11
Speaker 1: But then if I moved in the fourth dimension, someone
15:14
Speaker 1: looking at me right here in the room wouldn't see
15:16
Speaker 1: me move. Right. Technically, that's right, they wouldn't see you
15:19
Speaker 1: move in three D. But it depends on your shape
15:22
Speaker 1: in the fourth dimension, right, And again it's hard to
15:25
Speaker 1: think about. So it's a little easier to step down
15:27
Speaker 1: in dimensions and think about like two versus three dimensions.
15:31
Speaker 1: Imagine we were living on a two D surface and
15:34
Speaker 1: somebody passed a stick through that two D surface. What
15:36
Speaker 1: would we see. We would just see like a slice
15:39
Speaker 1: of the stick. It would look like, you know, a
15:40
Speaker 1: flat circle, and even if it was moving in that
15:43
Speaker 1: extra dimension, we couldn't tell. I think that's the example
15:46
Speaker 1: you were giving. But what if it wasn't a stick.
15:48
Speaker 1: What if it was like a pyramid or a sphere, right,
15:52
Speaker 1: and we smooved that sphere through our two D slice,
15:56
Speaker 1: then we would see a flat circle that was growing,
15:59
Speaker 1: and then would grow and we get larger as the
16:01
Speaker 1: center of the sphere passed through a plane, and then
16:04
Speaker 1: it would shrink again as the back half of the
16:06
Speaker 1: sphere pass through a plane, and then it would disappear.
16:08
Speaker 1: So motion in the fourth dimension can be visible in
16:11
Speaker 1: your three dimensions, depending on your shape in that fourth dimension.
16:15
Speaker 1: M m m. Yeah. Like imagine, for example, that you
16:21
Speaker 1: were a three D person and I was a two
16:23
Speaker 1: D person, and I like try to put you in prison.
16:26
Speaker 1: I like build walls around you in my two D world.
16:28
Speaker 1: You would just laugh at me. You would just like
16:30
Speaker 1: step over them, right, because I'm just like drawing a
16:33
Speaker 1: box on the ground around you. It's no big deal
16:35
Speaker 1: for you to like escape my two D prison because
16:38
Speaker 1: you're a three D person. You can just like go
16:40
Speaker 1: up and over it. And from my point of view,
16:42
Speaker 1: it would be like you just disappear from my prison
16:45
Speaker 1: cell and appear on the other side of it. I
16:47
Speaker 1: wouldn't be able to understand how you had gone from
16:50
Speaker 1: inside to outside. In the same way, if a four
16:53
Speaker 1: D person is in a three D prison, in principle,
16:57
Speaker 1: they could move through that fourth dimension right and appear
17:01
Speaker 1: outside the prison. Cell Ummm. This is really hard because
17:05
Speaker 1: I feel like we're trying to describe four dimensions with
17:07
Speaker 1: one dimension, which is sound, which is a pretty impossible.
17:13
Speaker 1: But you say it sort of depends on your shape,
17:15
Speaker 1: I guess, But does that sort of depend on the
17:17
Speaker 1: idea that you are projecting onto a plane or a
17:21
Speaker 1: three dimensions? Like, isn't it possible that I still am
17:25
Speaker 1: projecting onto a plane, but I'm also moving in a
17:29
Speaker 1: fourth dimension without that changing that doesn't really depend on
17:32
Speaker 1: my shape. That's totally possible, it's just not necessary. There's
17:35
Speaker 1: lots of different configurations. It's possible for you to be
17:38
Speaker 1: moving in the fourth dimension and not have any apparent
17:40
Speaker 1: motion in the third dimension, just like you know, you
17:43
Speaker 1: could be moving in Z without changing anything in X
17:46
Speaker 1: and Y and that totally works. But it's also it
17:50
Speaker 1: is possible to move in the fourth dimension and to
17:53
Speaker 1: have that motion affect how you look in three dimensions.
17:56
Speaker 1: M all right. So it's tricky and we're not quite
18:00
Speaker 1: sure how it would work, right because we sort of
18:02
Speaker 1: don't know what our shape would be in the fourth dimension. Yeah, exactly,
18:05
Speaker 1: Like I could be a really long cylinder or I
18:07
Speaker 1: could be a sphere, right, yeah exactly. Or I could
18:10
Speaker 1: be you know, a really attractive you know perimeter, yeah,
18:14
Speaker 1: or you could be shaped like a peanut. Like we
18:15
Speaker 1: just we just don't know. We have no idea, you know,
18:18
Speaker 1: if a fourth dimension exists and what our extent in
18:21
Speaker 1: that fourth dimension would be. We also don't know the
18:24
Speaker 1: nature of that dimension. Like we're imagining that fourth dimension
18:27
Speaker 1: as if it's a flat dimension that goes on forever,
18:31
Speaker 1: just like X, Y and Z, but we don't actually
18:33
Speaker 1: even know if that's true, right, Yeah, And this actually
18:37
Speaker 1: answers another question we've got from a listener almost on
18:39
Speaker 1: the same topic. Yeah, exactly. People are thinking about four dimensions,
18:43
Speaker 1: and so we had Tom right in and ask his question. Here.
18:47
Speaker 1: It is Hi, Daniel and Johai. I'm tall, and I
18:50
Speaker 1: have a question about the fourth dimension. Can life forms
18:53
Speaker 1: exist in the fourth dimension? And if so, how would
18:56
Speaker 1: we interact with them? Good question, Tom, Yeah, I think
18:59
Speaker 1: we have answered it already, right, which is that would
19:02
Speaker 1: we be able to see them? Maybe? Maybe not? It
19:04
Speaker 1: so it depends on your shape in this fourth dimension,
19:06
Speaker 1: Like you could maybe have a really long shape in
19:09
Speaker 1: the fourth dimension, or you could not, right, yeah, exactly,
19:12
Speaker 1: So it depends on the nature of that fourth dimension
19:15
Speaker 1: and our shape in that fourth dimension, like what our
19:18
Speaker 1: extent is in that dimension, And we just don't know
19:21
Speaker 1: because we can't sense or detect the fourth dimension if
19:23
Speaker 1: it exists, so we just don't really know the answer
19:26
Speaker 1: to that question. But if the universe is four D
19:29
Speaker 1: and there's a life form out there that lives in
19:31
Speaker 1: that fourth dimension as well, you know, and looks at
19:34
Speaker 1: us the way we would look at people living on
19:36
Speaker 1: the surface of a piece of paper, then you know,
19:38
Speaker 1: it would have a much more complex and nuanced relationship
19:41
Speaker 1: with that dimension, and it could probably literally run circles
19:43
Speaker 1: around us. Yeah, and what they look like, thannas, it's
19:46
Speaker 1: the question, I think. And they have purple skin, they
19:50
Speaker 1: would be glowing blue of course. All right, well, let's
19:53
Speaker 1: get into why we think there might be more than
19:56
Speaker 1: three dimensions and also what those dimensions could be. But
20:00
Speaker 1: first let's take a quick break. All right, we're talking
20:14
Speaker 1: about four dimensions, and the tests are act which is
20:18
Speaker 1: not a blue cube in a superhero movie, but a
20:20
Speaker 1: geometric shape in four dimensions. Yeah, and I guess when
20:23
Speaker 1: we say it's a cuban four dimensions, because the cube
20:25
Speaker 1: is kind of like your most basic shape. Yeah, you
20:28
Speaker 1: could also imagine a four D sphere. I suppose, right,
20:30
Speaker 1: you can play the same game. You could say you
20:32
Speaker 1: have a dot in zero dimensions, you have a circle
20:35
Speaker 1: in two dimensions, you have a sphere in three dimensions.
20:39
Speaker 1: I'm not sure what a circle would be like in
20:40
Speaker 1: one dimension, but you can go zero to three, and
20:43
Speaker 1: then I suppose you could imagine a four dimensional sphere
20:46
Speaker 1: where the surface has the same distance from the central point,
20:50
Speaker 1: including the fourth dimensional distance. I think you can play
20:53
Speaker 1: similar games in four D for other objects. But yeah,
20:56
Speaker 1: a cube is sort of like the basic thing because
20:59
Speaker 1: you're moving perpendicular in all four directions, and so it's
21:03
Speaker 1: like the building block. Yeah, well step us through. Why
21:05
Speaker 1: do we think there might be more dimensions? Is it
21:08
Speaker 1: based on theory or a hunter just just like wild possibility.
21:13
Speaker 1: It's based on wild theories from physicists gone wild, of course, Yeah, exactly.
21:19
Speaker 1: You know, sometimes it's just the math works better if
21:22
Speaker 1: you assume more dimensions, Like we try to write down
21:26
Speaker 1: theories of physics that makes sense, and sometimes they just
21:29
Speaker 1: don't really work. And it turns out if you like
21:31
Speaker 1: assume that space has more dimensions, then all of a sudden,
21:35
Speaker 1: the math gets not simpler, it gets more complicated, but
21:38
Speaker 1: it fits together in a more natural way. Really, it
21:41
Speaker 1: makes the math easier, or it makes it make more sense.
21:44
Speaker 1: Like you're doing the math and something's not fitting quite right.
21:47
Speaker 1: But if you added a whole new dimension, you know,
21:49
Speaker 1: things would be smoother, exactly. And one of the places
21:53
Speaker 1: this comes up is in trying to understand the universe
21:55
Speaker 1: that a really really small scale, you know, down deep
21:58
Speaker 1: below atoms, below, nuclei, below protons, below, quarks, much much
22:03
Speaker 1: deeper down the very smallest scale. We don't know what
22:05
Speaker 1: the nature of the university is, but people have speculations,
22:08
Speaker 1: ideas business gone wild, think about how maybe it's made
22:12
Speaker 1: out of tiny little vibrating strings, and these strings vibrate
22:16
Speaker 1: in some funny dimensions, and so in order to make
22:19
Speaker 1: those calculations work, like to have those strings vibrate and
22:23
Speaker 1: have those vibrating strings turn into particles. At our scale,
22:27
Speaker 1: you need more ways for those strings to vibrate. You
22:30
Speaker 1: need for them to be able to wiggle in certain ways,
22:32
Speaker 1: and to make sheets when they wiggle, and to make
22:34
Speaker 1: complicated structures, and those structures make a lot more sense.
22:38
Speaker 1: It turns out if the universe has something like eleven
22:41
Speaker 1: dimensions rather than just three, because with only three dimensions, like,
22:46
Speaker 1: what's the problem, you can't get sort of the richness
22:48
Speaker 1: that you see in our universe. Yeah, you don't get
22:50
Speaker 1: the richness, you don't get the results you want. And
22:52
Speaker 1: also sometimes things just collapse, Like if you try to
22:55
Speaker 1: do calculations in string theory and go for more than
22:58
Speaker 1: eleven dimensions, like up to twenty four or thirty nine dimensions,
23:03
Speaker 1: that it always just sort of ends up collapsing back
23:05
Speaker 1: down to eleven dimensions. It's just like the most natural
23:08
Speaker 1: way to express some of these theories is in eleven dimensions,
23:12
Speaker 1: and that makes us wonder, like, wells that just mathematics
23:14
Speaker 1: or is that actually reflecting something fundamental about the universe?
23:18
Speaker 1: You know, often if physics were doing this, we're like
23:20
Speaker 1: noticing a pattern about the way things seem to work
23:23
Speaker 1: mathematically and wondering, who does that reflect something real in
23:27
Speaker 1: the universe. Is that like how we're discovering something about
23:30
Speaker 1: the structure of the universe or is this just the
23:32
Speaker 1: way we write things down because we're humans and that's
23:34
Speaker 1: where our brains work, And you know, it's a deep question.
23:37
Speaker 1: We just don't know the answer to right, is it
23:39
Speaker 1: maybe just physicists not wanting to do any more math?
23:43
Speaker 1: That's just add more dimensions? Why not more dimensions? This
23:47
Speaker 1: more math, man, it makes it more complicated. You know,
23:50
Speaker 1: eleven dimensional integral it's like, you know, eleven times harder
23:54
Speaker 1: than a three dimensional integraw. But yeah, sometimes the math
23:57
Speaker 1: just works. And it also makes for a cooler grand
24:00
Speaker 1: title grant application form. Yeah, but the money you get
24:04
Speaker 1: from that grant then gets thinner and thinner because it
24:06
Speaker 1: spreads out through all eleven dimensions, it gets diluted. Yeah,
24:10
Speaker 1: but you can build a grant in more dimensions than three. Yeah,
24:13
Speaker 1: maybe we can find funding agencies that work in these
24:16
Speaker 1: other dimensions as well. All right, Well, there's also this
24:18
Speaker 1: other idea that maybe more dimensions explains gravity in some way, right,
24:23
Speaker 1: like why gravity seems so weak? Or how can we
24:26
Speaker 1: kind of resolve this conflict between special relativity and quantum physics.
24:32
Speaker 1: There's other excuses for adding more dimensions. It's a really
24:35
Speaker 1: tempting idea for lots of reasons. And one is, you say,
24:38
Speaker 1: is to explain this mystery of gravity. You know, of
24:41
Speaker 1: all the fundamental forces, the strong force, the weak force, electromagnetism.
24:45
Speaker 1: Gravity is the weakest, and not by a little bit,
24:48
Speaker 1: but like ten to the thirty. So it's just like
24:51
Speaker 1: so much weaker than the other forces. And we physicists
24:54
Speaker 1: we like harmony. We like things to sort of fit
24:56
Speaker 1: together and be explainable as part of a package. When
25:00
Speaker 1: one thing really sticks out, we don't like that. We
25:02
Speaker 1: look for an explanation for why that might be. And
25:04
Speaker 1: as you say, the idea is that gravity might not
25:07
Speaker 1: actually be super weak. It might just seem like it's
25:10
Speaker 1: super weak because it's spreading out in these other dimensions.
25:14
Speaker 1: Remember that the power of gravity gets weaker as you
25:17
Speaker 1: get further away from something. Currently, we measured that to
25:20
Speaker 1: be like one over the distance squared, But if you
25:22
Speaker 1: actually had more dimensions than just three, then the distance
25:25
Speaker 1: would grow more rapidly because you'd be moving away in
25:28
Speaker 1: more dimensions. So if gravity actually moves through all these
25:32
Speaker 1: other dimensions as well, then the reason it feels weak
25:35
Speaker 1: is that it's spreading out through those dimensions, that your
25:37
Speaker 1: distance from the other object is actually greater than it
25:39
Speaker 1: seems like it is in just three dimensions. So maybe
25:43
Speaker 1: gravity is just as powerful as these other forces. It's
25:45
Speaker 1: just mostly getting wasted in the other eight or whatever dimensions,
25:49
Speaker 1: And so that would be super awesome because it would
25:52
Speaker 1: let us like discover other dimensions of the universe and
25:55
Speaker 1: also solve this really deep mystery about why gravity seems
25:58
Speaker 1: so different from the other forces, right, And the idea
26:01
Speaker 1: is that the other forces, like magnetism and the strong
26:04
Speaker 1: and the weak forces, they only act in the three
26:07
Speaker 1: dimensions that we know, right, or they're like more focused
26:09
Speaker 1: in our regular dimensions and they're they're not acting in
26:13
Speaker 1: the other dimensions like gravity is, yeah, exactly, and that's
26:16
Speaker 1: a question we don't know the answer to, like why
26:18
Speaker 1: would that be? And as often happens in physics, if
26:21
Speaker 1: you have found those dimensions and discover the gravity is
26:24
Speaker 1: the only one that moved through them, then you'd be
26:26
Speaker 1: left with another, maybe deeper question, which is like, well,
26:29
Speaker 1: what's different about gravity that it moves through these other
26:31
Speaker 1: dimensions but electromagnetism doesn't and the strong force doesn't. So
26:35
Speaker 1: you know, we're never going to run out of those questions,
26:37
Speaker 1: even if we make crazy discoveries about the nature of space. Right.
26:41
Speaker 1: So basically you would wait the same in other dimensions,
26:44
Speaker 1: but your cell phone and your magnets wouldn't work. That
26:48
Speaker 1: would be inconvenient. Yeah, exactly. But it also means that
26:53
Speaker 1: gravity might be much more powerful than we thought, and
26:56
Speaker 1: that if you managed to get really really close to something,
26:59
Speaker 1: if you can, for example, two particles super duper close
27:03
Speaker 1: together so their distance actually gets very very small, that
27:06
Speaker 1: you might see that very strong gravity. And that's why
27:09
Speaker 1: people think we might make many black holes at the
27:11
Speaker 1: Large Hadron Collider, because two protons getting pushed really really
27:15
Speaker 1: close together might trigger super strong gravity and create a
27:19
Speaker 1: black hole. That's the whole idea behind making many black holes.
27:23
Speaker 1: It might actually reveal the existence of other dimensions of
27:26
Speaker 1: space and time. Hey, let's give it a try. That
27:28
Speaker 1: sounds like a good idea. Let's make black holes here. Yeah,
27:33
Speaker 1: and let's do it million times a second. Yeah, what's
27:36
Speaker 1: the worst, Like, let's just go wild, all right? Well,
27:40
Speaker 1: there's also the idea that maybe the fourth dimension or
27:43
Speaker 1: the extra dimensions are not necessarily related to space, like
27:47
Speaker 1: a direction that we can move in or kind of
27:50
Speaker 1: like wiggle around in. There's also the idea that maybe
27:53
Speaker 1: this fourth dimension is timet exactly. The way we were
27:56
Speaker 1: talking about gravity a moment ago was as a force
27:59
Speaker 1: that gets weaker as it propagates through space, and that's
28:02
Speaker 1: sort of like the quantum mechanical views like trying to
28:04
Speaker 1: understand gravity is one of the other forces and maybe
28:07
Speaker 1: finding a quantum theory of it. But you're right, there's
28:09
Speaker 1: another way to look at gravity, and that's part of relativity.
28:13
Speaker 1: And relativity tells us that there's a deep connection between
28:16
Speaker 1: the three dimensions of space that we're familiar with and time.
28:19
Speaker 1: So it's like you were saying earlier, like do the
28:21
Speaker 1: dimensions all have to be space? Could they be like
28:24
Speaker 1: flavor or color or you know, sourness or whatever. But
28:28
Speaker 1: you're right, it's cool to think about other dimensions and
28:31
Speaker 1: have them be not necessarily just motion in space, but time.
28:34
Speaker 1: And the more we learn about space and special relativity,
28:38
Speaker 1: the more it feels like time should get promoted to
28:41
Speaker 1: like one of the dimensions. Promoter. Are you saying time
28:45
Speaker 1: is lesser than space, Daniel, you're saying it needs and promotion.
28:49
Speaker 1: I'm saying it's segregated. It's like put by itself. You know,
28:51
Speaker 1: quantum mechanics likes to say the time is really separate
28:54
Speaker 1: from space, that the two things are different, and you know,
28:57
Speaker 1: space can do all sorts of things that time can't do. Like,
29:00
Speaker 1: you know, you can go backwards and forwards in space
29:02
Speaker 1: and you can't do that in time. So it would
29:03
Speaker 1: be super awesome if we understood time is actually part
29:07
Speaker 1: of some four D object, which was three spatial dimensions
29:11
Speaker 1: and this one weird time to mention. I think that
29:13
Speaker 1: would be a promotion for time to get graduated up
29:16
Speaker 1: to a full dimension. Right, but you know what is
29:18
Speaker 1: space without time? Then? You know, do you think about it?
29:22
Speaker 1: It's brief. I can exist without space or you know,
29:25
Speaker 1: time doesn't need three dimensions of space. You know, I
29:28
Speaker 1: would could hang out with two dimensions of space. Yeah,
29:31
Speaker 1: that's true. So really, I mean, I think time is
29:33
Speaker 1: just cooler. It's more, it's more timeless. It's a classic. Yeah,
29:39
Speaker 1: you know, there's something good about everybody, but it's also
29:42
Speaker 1: just cool to understand them as part of the bigger picture.
29:45
Speaker 1: And I think there's something really beautiful. They're something really
29:48
Speaker 1: deep and insightful, and understanding time is part of this
29:51
Speaker 1: for D object. You know, it's not just like, hey,
29:54
Speaker 1: there's some similarities, let's write them down together. It's that
29:57
Speaker 1: the concept makes much more sense when you put them together.
30:00
Speaker 1: Then when you leave them apart. Special relativity really shows
30:04
Speaker 1: us that it shows us that space and time are
30:06
Speaker 1: really closely connected in the same way that the three
30:09
Speaker 1: spatial dimensions are really closely connected. You know, the universe
30:13
Speaker 1: makes much more sense if you look at it in
30:15
Speaker 1: three dimensions, and it turns out it makes even more
30:17
Speaker 1: sense if you packed it all together into a four
30:20
Speaker 1: dimensional concept. Right. This is the concept of space time, right,
30:24
Speaker 1: like you treated all is one concept or one thing
30:28
Speaker 1: or one like coordinate system that we live in. Yeah, exactly,
30:32
Speaker 1: you think about it is like one coordinate system, and
30:34
Speaker 1: some things just make more sense in that coordinate system.
30:37
Speaker 1: You know. Take for example, the length of an object
30:40
Speaker 1: in three dimensional space, right, doesn't really matter how you
30:44
Speaker 1: measure it, you know, or where your axes are, how
30:46
Speaker 1: you define your X, y and z. The length of
30:48
Speaker 1: a stick is the length of a stick, and you
30:50
Speaker 1: can turn that stick around and it still has the
30:52
Speaker 1: same length, right, And that would be true if you're
30:55
Speaker 1: only looking at like a two D slice of it.
30:57
Speaker 1: If you're only looking at a two D slice of
30:58
Speaker 1: that stick, it would seem like it changing length as
31:01
Speaker 1: you like rotated it around or whatever. But we know
31:03
Speaker 1: the stick has a certain length, and so we want
31:06
Speaker 1: our measurement system to reflect that. Well, the same thing
31:09
Speaker 1: is actually true in space time. If you add time
31:13
Speaker 1: to your universe as the fourth dimension, then you can
31:16
Speaker 1: have a new definition of distance, which is called a
31:18
Speaker 1: space time interval, which is a distance in space and
31:22
Speaker 1: in time. You like add another bit to the calculation.
31:25
Speaker 1: And we know in our universe that like distance between
31:28
Speaker 1: objects is actually weird. It depends on how where you
31:31
Speaker 1: are and how fast you're going, and that the distance
31:33
Speaker 1: in time between objects depends also on how fast you're going.
31:37
Speaker 1: This is like length contraction and time dilation. The universe
31:40
Speaker 1: seems really weird, like it doesn't follow a lot of rules.
31:43
Speaker 1: It turns out in four D it does follow those rules,
31:46
Speaker 1: and like the four D space time interval, it doesn't
31:50
Speaker 1: change no matter what reference frame you're in how you
31:52
Speaker 1: rotate your measuring stick. So there are these properties, these
31:56
Speaker 1: principles that are respected only in four dimensional space and
31:59
Speaker 1: not in three dimensional space. And that's what makes us
32:01
Speaker 1: think that the four D spaces like more natural, that
32:04
Speaker 1: it's the better way to think about the universe. M
32:07
Speaker 1: It's like you don't need a special kind of math
32:09
Speaker 1: or a whole different set of equations to deal with time.
32:12
Speaker 1: You can use the same equations if you treat it
32:14
Speaker 1: another dimension. Yeah, you can use the same equations, and
32:17
Speaker 1: a bunch of stuff now suddenly makes sense, and it
32:19
Speaker 1: is simple if you do the math altogether. You know,
32:22
Speaker 1: for example, our laws of physics don't change if you
32:26
Speaker 1: rotate them in four dimensional space. What that means is
32:29
Speaker 1: that they're the same for everybody in an inertial reference frame.
32:32
Speaker 1: It doesn't matter where you are and how fast you're going.
32:35
Speaker 1: You can always apply the same laws of physics, electromagnetism
32:39
Speaker 1: and the strong force. All that can be applied no
32:41
Speaker 1: matter who you are and how fast you're going. That's
32:44
Speaker 1: not true. If you ignore that fourth dimension, you're like
32:46
Speaker 1: missing part of the story. Mmmmm, I guess It's kind
32:49
Speaker 1: of like if I'm sitting here doing nothing, you know,
32:52
Speaker 1: taking it up. Maybe it doesn't look like I'm moving
32:55
Speaker 1: in the three special dimensions, but I'm actually sort of
32:58
Speaker 1: moving in the time dimension right, Yes, yes, exactly. And
33:01
Speaker 1: the distance between your like spacetime locations right can be
33:06
Speaker 1: measured in that four dimensional space. You have zero distance
33:10
Speaker 1: in x, y and z, but you have a non
33:12
Speaker 1: zero distance in time, right, So it only looks like
33:15
Speaker 1: I mean lazy and inactive, But really I'm like working
33:19
Speaker 1: out in the time dimension, right, I'm like going for
33:21
Speaker 1: a job. You're getting strong in time exactly. And somebody
33:25
Speaker 1: else flying by near the speed of light might have
33:28
Speaker 1: a different opinion about exactly when one event happened, but
33:31
Speaker 1: they would make the same measurement of your space time interval,
33:34
Speaker 1: your distance, and four dimensions between the beginning of your
33:37
Speaker 1: workout and the end of your workout. I see, I
33:41
Speaker 1: would look good no matter how fast you're going. Yes,
33:44
Speaker 1: your beauty is invariant. All right, Well, let's talk about
33:48
Speaker 1: how this relates to quantum physics and special relativity, and
33:52
Speaker 1: also let's talk about how it shows up in The Avengers.
33:55
Speaker 1: But first let's take another quick break. We're talking about
34:09
Speaker 1: the tests or act Daniel, and now in the Avengers
34:12
Speaker 1: the Tests I act shows up I think in the
34:15
Speaker 1: thor movies First or or No Captain America. Maybe. Yeah,
34:19
Speaker 1: So it's this cube, right, and I think it's actually
34:21
Speaker 1: in these movies it's a vessel. It's just like holds
34:25
Speaker 1: the space stone, one of these six infinity stones, and
34:29
Speaker 1: so like somebody at some point earlier on the Marvel
34:32
Speaker 1: Universe took the Infinity Stone and put it inside this
34:35
Speaker 1: cube which they call a test Aract to make it
34:38
Speaker 1: like sound awesome in science, right, I think it's called
34:41
Speaker 1: making it up as you go along in terms of
34:44
Speaker 1: the writing craft there. But yeah, it turns out that
34:49
Speaker 1: the talk connected and in particularly the tests I act
34:51
Speaker 1: and this one is the space Stone, right, like it's
34:54
Speaker 1: somehow control space and lets you like create warm holes
34:57
Speaker 1: and things like that. Yeah, the space Stone has a
34:59
Speaker 1: lot of power unless you do all sorts of crazy stuff.
35:01
Speaker 1: And so the space Stone itself is not the tests Irac,
35:04
Speaker 1: but the tests Ract is this thing which holds it
35:07
Speaker 1: and you know, test React we know now is a
35:09
Speaker 1: four dimensional cube, but in the Avengers movie they use
35:12
Speaker 1: a three D cube because I guess, you know, it's
35:14
Speaker 1: harder to write a four D cube or even the
35:16
Speaker 1: special effects that Marvel Studios can't do four D movies,
35:20
Speaker 1: and so it's really just a three D C but
35:22
Speaker 1: it's glowing blue, right, So maybe in the Marvel movies,
35:25
Speaker 1: color is the fourth dimension. Well, technically if you're watching
35:29
Speaker 1: in three D, you are watching a four D movie
35:31
Speaker 1: because it is playing out in time that's true, right, Yeah,
35:35
Speaker 1: exactly right. So if you saw the Avengers in three D,
35:38
Speaker 1: you probably did see a four D test a rack
35:41
Speaker 1: containing the Space Stone. So congrats to you. Right, and
35:44
Speaker 1: then I see your notes here that it's powered by
35:47
Speaker 1: dark energy, where they just like throwing all kinds of
35:49
Speaker 1: physics terms in there to try to impress people. Yeah, exactly.
35:52
Speaker 1: I don't know who the science consultant was for that movie,
35:56
Speaker 1: but you know, they give them a broad introduction to
35:58
Speaker 1: everything about the universe, and they just like cherry picked
36:00
Speaker 1: the words that sounded cool, and hey, dark energy does
36:03
Speaker 1: sound cool. So it's nice to know that if the
36:05
Speaker 1: Space Stone were real, it would be somehow powered by
36:09
Speaker 1: this mysterious force that's accelerating the expansion of the universe.
36:13
Speaker 1: I might have to marvel a fact check that. I
36:16
Speaker 1: think maybe it was another stone that was powered by
36:19
Speaker 1: dark energy, maybe the Red one. Maybe I'm not quite sure. Yeah,
36:23
Speaker 1: you you certainly might be right. I just remember watching
36:26
Speaker 1: this movie and going, oh, dark energy, that sounds fun.
36:30
Speaker 1: Now you were watching in black and white or something.
36:33
Speaker 1: Maybe I was watching it backwards in time accidentally, right,
36:38
Speaker 1: And it also shows up in other words, right, and
36:40
Speaker 1: the wrinkle in Time books, right, Yeah, The Wrinkle in
36:43
Speaker 1: Time is a really fun book which recently made into
36:45
Speaker 1: a pretty good movie. And in that book they can
36:48
Speaker 1: travel all around the universe and they call the fifth
36:52
Speaker 1: dimension a test I act. So like a tests iact
36:55
Speaker 1: is a four D cube in our universe, but in
36:57
Speaker 1: a Wrinkle in Time universe, the whole fifth dimension is
37:01
Speaker 1: a tests iract and you can like add that to
37:03
Speaker 1: other four dimensions as you travel through space without like
37:07
Speaker 1: having to go the long way around. So it's sort
37:09
Speaker 1: of like a portable wormhole you can use to get
37:13
Speaker 1: from one spot to the other. Wait, what the fifth
37:16
Speaker 1: dimension is actually a four dimensional cube? In that movie,
37:19
Speaker 1: they sort of brush over the tests Iract as a
37:21
Speaker 1: four D cube and they just call the tests Iract
37:23
Speaker 1: the fifth dimension. And so imagine if like space and
37:26
Speaker 1: time are four dimensions, and you wanted to get to
37:29
Speaker 1: somewhere else in the universe, and you wanted to do
37:32
Speaker 1: it without going through four D space, if you could
37:35
Speaker 1: somehow move in the fifth dimension, if the universe is
37:37
Speaker 1: like bent in the fifth dimension, so that you could
37:40
Speaker 1: like hop from one part of our four D sheet
37:43
Speaker 1: to another part of the four D sheet by moving
37:45
Speaker 1: in that fifth dimension. That's sort of like what wormholes
37:49
Speaker 1: do in our universe. So it's sort of like, you know,
37:51
Speaker 1: a little shortcut, m I see. It's kind of the
37:54
Speaker 1: idea that maybe, like here where we are now is
37:57
Speaker 1: and Jupiter, which is really far away or we think
38:00
Speaker 1: really far away, could be really close to each other
38:02
Speaker 1: in another dimension, right Like if I could somehow reach
38:06
Speaker 1: out in another dimension, maybe I could just reach out
38:08
Speaker 1: and touch Jupiter exactly. Imagine our universe again, just as
38:12
Speaker 1: a sheet and then like roll it up. Then all
38:15
Speaker 1: of a sudden, you're close to another layer of that sheet.
38:19
Speaker 1: And if you like went through our universe space, it
38:22
Speaker 1: would take you forever to get there. But you know,
38:24
Speaker 1: in this like other direction, the direction in which our
38:27
Speaker 1: universe is like a rolled up sheet or folded or whatever,
38:30
Speaker 1: then you could just hop from one part of the
38:32
Speaker 1: sheet to the other, moving in that other dimension. But
38:35
Speaker 1: you know, we don't know that that dimension exists, but
38:37
Speaker 1: in a ringle in time, it does exist. So it's
38:40
Speaker 1: sort of this like cool wormhole strategy. But for a
38:43
Speaker 1: reason that just really doesn't make any sense to me
38:45
Speaker 1: other than that it sounds cool and science e They
38:47
Speaker 1: call that fifth dimension the tests I Act, right, And
38:51
Speaker 1: it also shows up in the inter Sellar movies, right,
38:54
Speaker 1: like Matthew McConaughey goes into a black hole and he's
38:56
Speaker 1: somehow like navigating a tests I act where time is
39:00
Speaker 1: another dimension and he's able to like send messages to
39:04
Speaker 1: his daughter in the future. Right, Yeah, there is some
39:07
Speaker 1: weird stuff where Interstellar you go into the black hole
39:11
Speaker 1: and space and time are all twisted up. And it's
39:14
Speaker 1: certainly true that in a black hole, space and time
39:17
Speaker 1: are a very confusing, right, and like time and space
39:20
Speaker 1: sort of like switch relationships, and space is only forwards,
39:24
Speaker 1: you know. Outside of the black hole, time can only
39:27
Speaker 1: move forwards. Inside the black hole, you can only move
39:30
Speaker 1: sort of one direction in space, sort of forwards towards
39:33
Speaker 1: the singularity. As some people say that inside the black hole,
39:38
Speaker 1: space has become time, like so I think that's the
39:40
Speaker 1: origin of that. But in the movie, you know, he
39:43
Speaker 1: can then like move through time, but he moves through
39:46
Speaker 1: time as part of the story, so there still is time.
39:49
Speaker 1: There's like a time when he was earlier in time
39:51
Speaker 1: and a time when he was later in time. You know, honestly,
39:54
Speaker 1: it doesn't make any actual sense, but it's uh, you know,
39:57
Speaker 1: it makes for a poignant scene. You mean, Christopher Nolan
40:01
Speaker 1: movie doesn't make sense with regards to time. That's so weird.
40:05
Speaker 1: You know. I recently watched Tenant, which is really fun,
40:09
Speaker 1: but I had the impression the whole time that like, wow,
40:11
Speaker 1: I either I am not following because I'm not smart enough,
40:14
Speaker 1: or this makes no sense and I can't tell which
40:17
Speaker 1: it is. You couldn't tell, really tell, And I try
40:21
Speaker 1: to map it out and try to watch a scene
40:22
Speaker 1: by scene and be like, Okay, what's going on here?
40:24
Speaker 1: How does that make sense? Trying to build a map
40:27
Speaker 1: of like what's going on in that universe? But wow,
40:29
Speaker 1: it's very confusing, And eventually I just went on to
40:31
Speaker 1: read it, and of course somebody else had watched the
40:33
Speaker 1: movie like a hundred times and built a map. But
40:35
Speaker 1: even still, it's very confusing because it's hard to think
40:38
Speaker 1: about things moving backwards in time as the story moves forwards. Right, Yeah,
40:42
Speaker 1: I think the movie lost me at backwards oxygen. I
40:45
Speaker 1: was like, you need backwards oxygen to survive living backwards.
40:51
Speaker 1: I don't know how where are they going to get
40:52
Speaker 1: to so much oxygen backwards? Anyways? Yeah, so it shows
40:56
Speaker 1: up a lot in popular culture and movies and books,
40:59
Speaker 1: But extrat dimensions and the test arc are sort of
41:02
Speaker 1: real things that physicists are thinking about. Right, It might
41:04
Speaker 1: explain gravity, might explain how quantum mechanics and general relativity
41:08
Speaker 1: are connected. Right, it's a it's like a real thing.
41:11
Speaker 1: It's a real thing. It might be a real thing. Yeah,
41:13
Speaker 1: it's a real thing in science, and that it's a
41:16
Speaker 1: very valuable and useful way to think about the universe.
41:19
Speaker 1: And there's a larger lesson there, right, that we don't
41:22
Speaker 1: know the deep nature of the universe, and we keep
41:24
Speaker 1: making the same mistake as humans by imagining that the
41:28
Speaker 1: universe is the way we always thought it was. And
41:31
Speaker 1: so it's very healthy to try to like break out
41:33
Speaker 1: of the confines of our intuition and imagine different ways
41:36
Speaker 1: the universe might be. And this is a pretty deep one.
41:40
Speaker 1: So we'd like to be open minded about the nature
41:42
Speaker 1: of the universe and not just be stuck in three dimensions.
41:44
Speaker 1: And I think that's how we made this leap to
41:46
Speaker 1: thinking about the universe in four dimensions. This connection and
41:50
Speaker 1: special relativity between space and time really does show us
41:53
Speaker 1: that time is deeply connected to space in a way
41:56
Speaker 1: that's not just mathematical, real and physical, and that whole
42:00
Speaker 1: pully might help us bridge, as you say, between relativity
42:02
Speaker 1: and quantum mechanics. Is quantum mechanics is a very very
42:05
Speaker 1: different view of time. So whatever theory we come up with,
42:08
Speaker 1: whether it's string theory or something else, to bring these
42:11
Speaker 1: together and reveal the actual nature of the universe, it's
42:13
Speaker 1: got to definitely be something that figures out time and
42:16
Speaker 1: its relationship to space and all the other possible dimensions
42:19
Speaker 1: that might be out there, like they might be real. Yeah.
42:23
Speaker 1: I guess the history of science and physics and our
42:26
Speaker 1: exploration of it is that the universe is much more
42:30
Speaker 1: complex than we think it is. Right, There's more twit
42:33
Speaker 1: and what it seems like apparently, yeah, exactly. There might
42:35
Speaker 1: really be backwards oxygen and you might have to breathe
42:38
Speaker 1: it one day. Keep your mind open. Yeah, the universe
42:41
Speaker 1: might might be wilder than you think, exactly, And the
42:44
Speaker 1: universe is always builled with surprises, And so I look
42:47
Speaker 1: forward to learning about the deep nature of the universe
42:50
Speaker 1: and discovering other dimensions of space and or time. You know,
42:53
Speaker 1: we talked about other dimensions of space, but it's also
42:56
Speaker 1: possible there are the dimensions of time. What all right,
43:00
Speaker 1: let's get into that another time. Sounds good, But in
43:05
Speaker 1: the meantime we hope that answer the questions that our
43:07
Speaker 1: listeners had about the test are act and about living
43:10
Speaker 1: in four dimensions. You hope you enjoyed that. Thanks for
43:13
Speaker 1: joining us, see you next time. Thanks for listening, and
43:23
Speaker 1: remember that Daniel and Jorge explained. The Universe is a
43:26
Speaker 1: production of I Heart Radio. Or more podcast from my
43:30
Speaker 1: heart Radio visit the I heart Radio app, Apple Podcasts,
43:33
Speaker 1: or wherever you listen to your favorite shows.