Latest / Daniel and Kelly’s Extraordinary Universe / Are Wormholes Real?

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Are Wormholes Real? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Daniel. So we did an episode about teleportation, whether
0:11
Speaker 1: it's possible to go from one point in space to
0:14
Speaker 1: another point in space instantly, that's right, without actually moving
0:18
Speaker 1: through space. And the episode was very popular, but we
0:21
Speaker 1: got a ton of comments on Twitter and the Facebook's
0:25
Speaker 1: about something we may have missed. That's right. A lot
0:28
Speaker 1: of people commented that we didn't talk about one possible way,
0:32
Speaker 1: one important possible way to move to another part of
0:36
Speaker 1: the universe very rapidly. Yeah, like there's a loophole in
0:40
Speaker 1: the laws of the universe. Perhaps I don't think this
0:45
Speaker 1: counts as a loophole. I don't think it counts as teleportation,
0:48
Speaker 1: but we'll dig into it. Him and I'm Daniel. Welcome
1:08
Speaker 1: to our podcast. Daniel and Jorge explain the Universe, in
1:11
Speaker 1: which a physicist and a cartoonist try to take the
1:14
Speaker 1: universe apart, break it into pieces you can understand, and
1:17
Speaker 1: download them one at a time into your brain. Today
1:20
Speaker 1: on the episode, we're going to talk about possible loophole
1:24
Speaker 1: in the laws of physics worm more molds. A lot
1:34
Speaker 1: of people commented when we talked about teleportation that wormholes
1:37
Speaker 1: might be another way to get from one place in
1:40
Speaker 1: space to another place in space without actually moving through space.
1:46
Speaker 1: And I'm going to take issue with that that. Yeah,
1:49
Speaker 1: wormholes might let you move um rapidly from one place
1:52
Speaker 1: in space to another, but it's not technically teleportation. But
1:56
Speaker 1: we'll dig into that in a moment. So, yeah, wormholes,
1:58
Speaker 1: they're they're kind of the basis of one of my
2:00
Speaker 1: favorite movie sci fi movies, which is Okay, good Contact interest,
2:06
Speaker 1: Why is Contact your favorite movie? It's one of my
2:08
Speaker 1: favorite movies just it's such a great, well me made movie.
2:13
Speaker 1: The storyline is is great, and it's just kind of
2:16
Speaker 1: this great character portrait of Jodie Foster's character kind of
2:19
Speaker 1: searching for answers out there in the universe. Yeah, it's
2:22
Speaker 1: also one of my favorite movies because it touches on
2:25
Speaker 1: a bunch of really interesting themes. First of all, of course,
2:27
Speaker 1: it's fascinating to have to potentially get a message from
2:30
Speaker 1: outer space that's like everybody's dream, right. But the other
2:33
Speaker 1: thing I really like about that movie is that it
2:35
Speaker 1: shows the process that a lot of the excitement of
2:37
Speaker 1: the plot is in unraveling the message. Right. You don't
2:40
Speaker 1: just get the message and boom you understand it. It's
2:42
Speaker 1: like in English, and it makes perfect sense. It's a
2:45
Speaker 1: puzzle and they have to figure it out and think
2:47
Speaker 1: about it, and then it clicks into place and all
2:48
Speaker 1: of a sudden, this gibberish turns into into physics and math.
2:52
Speaker 1: And to me, that was really exciting to see that
2:53
Speaker 1: process played out. Yeah, and I liked how you Know
2:56
Speaker 1: is based on a book written by Carl Sagan. Do
3:00
Speaker 1: of that, yes, Yeah, And so he really thought about
3:02
Speaker 1: the whole process of like, if we had to build
3:04
Speaker 1: this giant machine from a message from aliens, have would
3:08
Speaker 1: that happen? You know, what sort of international cooperations or
3:11
Speaker 1: organizations and how how would the engineering be done? And
3:16
Speaker 1: he really thought through all these kind of interesting political details. Yeah.
3:20
Speaker 1: I think Carl Sagon probably spent a lot of time
3:22
Speaker 1: thinking about how to talk to aliens and how to
3:24
Speaker 1: respond if they talk to us, and all sorts of stuff.
3:27
Speaker 1: I bet that dude smoked a lot of banana peals
3:29
Speaker 1: and had a lot of deep thoughts on the topic.
3:31
Speaker 1: Ate a lot of banana, right, probably ate a lot
3:34
Speaker 1: of bananas as well. That's why I don't think that
3:36
Speaker 1: puts you in the same frame of mind is smoking
3:38
Speaker 1: the peels. But it's probably helpful. Yeah, but anyways, in
3:42
Speaker 1: that movie, Jodie Foster's character goes to another galaxy through
3:48
Speaker 1: a wormhole. Like that's what. Sorry, I may have spoiled
3:51
Speaker 1: the plot, but they build a machine and it takes
3:53
Speaker 1: her through a wormhole and she travels to another part
3:56
Speaker 1: of the universe with through it. I think it's okay
3:59
Speaker 1: to spoil the plot twenty year old movies at this point,
4:01
Speaker 1: or Hey, you don't need to never talk about that movie.
4:04
Speaker 1: I think it's all right. Yeah, um, yeah, they in
4:06
Speaker 1: that movie they have like this intergalactic network. It's like
4:09
Speaker 1: a subway system where you can like zip from one
4:11
Speaker 1: place to the other um in order to get around
4:13
Speaker 1: and and it's a sort of a common trope that's
4:15
Speaker 1: like the thinking of humans as new on the scene
4:19
Speaker 1: and then maybe somebody else in the galaxy has already
4:21
Speaker 1: built this incredible infrastructure. And it's a common way that
4:25
Speaker 1: science fiction writers approached this problem of we're so isolated,
4:28
Speaker 1: we're so far from everybody else. How could we possibly
4:31
Speaker 1: have either an interstellar civilization of just humans or interact
4:36
Speaker 1: with and and live with and develop with and talk
4:38
Speaker 1: to communicate with aliens and other star systems When everything
4:42
Speaker 1: is so dang far apart. Yeah, so warmholes is kind
4:45
Speaker 1: of one way you could do it, at least in
4:47
Speaker 1: science fiction, is have these tunnels through space that connect
4:51
Speaker 1: really far away points. That's right. Typically you do either
4:54
Speaker 1: fasten the light travel or warp speed or wormholes. Right,
4:59
Speaker 1: and so we've covered two of those already, So it's
5:01
Speaker 1: time to dig into wormholes. Try to jump into the hole.
5:04
Speaker 1: It's worm our way into this holy topic. Well, as usually,
5:09
Speaker 1: we were wondering how many of you out there knew
5:12
Speaker 1: what a wormhole was and whether or not they're real,
5:15
Speaker 1: that's right. So I walked around and I asked a
5:17
Speaker 1: bunch of random people, one of whom was my wife,
5:19
Speaker 1: if they knew what wormholes were and if they thought
5:22
Speaker 1: they were a real thing out there in space or
5:24
Speaker 1: just sort of an idea and a head of science
5:26
Speaker 1: fiction authors, So does have you listening think about it
5:28
Speaker 1: for a second. Do you think wormholes are real? And
5:31
Speaker 1: do you know what they are? Here's what people had
5:34
Speaker 1: to say. Um, and the question was if that would
5:38
Speaker 1: be possible. It's a real thing, like it's out there,
5:40
Speaker 1: it's pretty somewhere. I don't think so. No, Yeah, that
5:45
Speaker 1: seems something like I would see like in a scientific
5:48
Speaker 1: or like a sci fi movie. But yeah, I don't.
5:50
Speaker 1: I don't think they're a real thing. I think so,
5:52
Speaker 1: I'm pretty sure, all right, I believe it's a distinct possibility.
5:57
Speaker 1: I don't. I will not say for sure that it
5:59
Speaker 1: is or it isn't, but I do believe the possibility
6:02
Speaker 1: remains open that there is ways to traverse through space. No,
6:06
Speaker 1: why not? I don't know. They just have this sci
6:09
Speaker 1: fi sheen about them. Probably maybe I don't know. I'm
6:15
Speaker 1: a chemical engineer, so it was not really my field,
6:18
Speaker 1: but it's possible. Yeah, in this case, I think a
6:20
Speaker 1: lot of people seem to have heard about wormholes, Like
6:23
Speaker 1: almost nobody has said what what the wormhole um? And
6:27
Speaker 1: a lot of people believe that they exist and and
6:30
Speaker 1: a lot of people believe that scientists will be able
6:32
Speaker 1: to make them. Yeah, a lot of people seem to
6:34
Speaker 1: know them from science fiction. Like it's kind of a
6:37
Speaker 1: well known science fiction idea and used a lot in
6:40
Speaker 1: science fiction. Yeah, it's a common trop um to solve
6:43
Speaker 1: that problem with with your your plot having people spread
6:47
Speaker 1: all over the galaxy. And so it's definitely something we
6:49
Speaker 1: should talk about because it's something that's out there. So
6:51
Speaker 1: I wonder if if that's a thing, like, if you
6:54
Speaker 1: show it enough in science fiction, eventually people will think
6:57
Speaker 1: it's just an engineering problem. I thought you were gonna
7:00
Speaker 1: say something else. If it's an if it appears in
7:03
Speaker 1: science fiction oft enough, does it become real? That would
7:06
Speaker 1: be pretty cool, right if if things that were right
7:09
Speaker 1: into novels eventually turned out to be reality because they
7:12
Speaker 1: were written into novels, that would be a cool sci
7:14
Speaker 1: fi novel right there. Yeah, well, sort of in a way.
7:16
Speaker 1: I mean, it's sort of becomes possible in the minds
7:21
Speaker 1: of people, and so engineers then go like, hey, what
7:23
Speaker 1: what will we need to make this happen? And so
7:25
Speaker 1: then um, yeah, you kind of have to believe that
7:28
Speaker 1: it's possible before you can try to do it, right,
7:30
Speaker 1: That's right. It might seem like a bit of a stretch,
7:32
Speaker 1: but I definitely include science fiction authors in the sort
7:35
Speaker 1: of spectrum of intellectuals who are responsible for creating the future.
7:39
Speaker 1: You know, in my mind, he goes from science fiction
7:41
Speaker 1: authors who do whatever they need to do to get
7:44
Speaker 1: inspired and think of crazy ways that that technology might
7:47
Speaker 1: change our society, to physicists who think is that at
7:51
Speaker 1: all possible, like even technically that could even ever happen,
7:54
Speaker 1: And once physicists sign off on it, then yeah, it
7:56
Speaker 1: gets dumped on the engineers like make it so. Yeah.
8:01
Speaker 1: But science fiction authors also have to know the science right,
8:04
Speaker 1: Like they can't just say like, hey, here, here is
8:06
Speaker 1: a pink unicorn that make helps you travel through space.
8:09
Speaker 1: Oh man, I don't know how much science fiction. I
8:13
Speaker 1: read a lot of science fiction, and a lot of
8:15
Speaker 1: it doesn't sound science at all. I just said they
8:18
Speaker 1: have to read signs, not understand signs. So what is
8:28
Speaker 1: a wormhole? A wormhole is a connection between two parts
8:33
Speaker 1: of space that otherwise seem very distant. Okay, And it's
8:38
Speaker 1: not a teleportation. It's not like I'm here in Los
8:41
Speaker 1: Angeles and I want to go to New York and
8:43
Speaker 1: I disappear from Los Angeles and then I appear in
8:45
Speaker 1: New York. That's teleportation with you, you appear in another
8:49
Speaker 1: place in space without actually moving through space. A wormhole
8:53
Speaker 1: is a very different solution. A wormhole says, can we
8:56
Speaker 1: create a connection between l A and New York? And
8:59
Speaker 1: I'm not talking about elon Musk underground tunnels or anything crazy.
9:02
Speaker 1: I'm saying, can you bring those two parts of space
9:05
Speaker 1: close together. Can you connect them so that you are
9:08
Speaker 1: still moving through space? But that the distance is very short? Right?
9:12
Speaker 1: So what does it mean to connect two points that
9:14
Speaker 1: are distant to each other? Meaning like, I'm here in
9:18
Speaker 1: Pasadena and next to me is another point in space,
9:22
Speaker 1: so I can move to that point in space. But
9:24
Speaker 1: you're saying that my point in space that I'm in
9:26
Speaker 1: right now could also potentially be connected to another point
9:29
Speaker 1: far away from here. That's right, And to understand this
9:32
Speaker 1: you need to relax a little bit your concept of
9:35
Speaker 1: what space is. Right, If you're thinking of space as
9:38
Speaker 1: like emptiness, like the backdrop, the stage on which the
9:42
Speaker 1: theater of the universe takes place, that's an old idea
9:45
Speaker 1: and it makes a lot of sense based on your experience, right,
9:47
Speaker 1: that's what how it seems to work. But that's but
9:50
Speaker 1: we have a more modern idea of space. Now. Space
9:52
Speaker 1: can do all sorts of weird things that that nothingness
9:55
Speaker 1: or emptiness or backdrop can't do, right, and most importantly,
10:00
Speaker 1: space can bend. Space has a shape. Okay, you know
10:03
Speaker 1: this is a very confusing topic for a lot of
10:05
Speaker 1: people to get their minds around, meaning that space is
10:08
Speaker 1: not rigid, you know, like a big empty warehouse that
10:11
Speaker 1: just it's it's there and it's fixed and it's square.
10:15
Speaker 1: You're saying space is more like I think the idea
10:18
Speaker 1: is more like spaces like like the ocean, you know,
10:20
Speaker 1: like it's like like we're swimming in water and this
10:23
Speaker 1: thing can kind of squish and bend and flow and
10:26
Speaker 1: and and push you in different directions. That's right. The
10:29
Speaker 1: ocean is a useful analogy because it tells you that
10:31
Speaker 1: this space can do all sorts of interesting things, and
10:34
Speaker 1: that we're embedded in it. And it's not an emptiness,
10:36
Speaker 1: it's a thing. It's a physical thing with behaviors. Right.
10:40
Speaker 1: And a very common way to think about the bending
10:42
Speaker 1: of space is to think about the bending of space
10:44
Speaker 1: in a higher dimension, and typically people use a two
10:48
Speaker 1: dimensional analogy. Now this analogy is flawed for one very
10:51
Speaker 1: important reason, which I'll tell you after we're done with
10:53
Speaker 1: the analogy, but it is still helpful in thinking about
10:56
Speaker 1: how space can move. So typically people think about space
10:59
Speaker 1: and two to pensions so that then they can then
11:01
Speaker 1: they can think about the bending of space and three dimensions,
11:04
Speaker 1: because it's really hard to think in four dimensions, right,
11:07
Speaker 1: bending of three dimensional space and four dimensions is hard,
11:09
Speaker 1: so let's just start with two. So you imagine your
11:12
Speaker 1: typical notion of two dimensional space might be like a
11:15
Speaker 1: rubber sheet, okay, and then we think about the bending
11:18
Speaker 1: of that spaces that bending in the third dimension, Like
11:21
Speaker 1: you put a heavy ball on the rubber sheet. What
11:22
Speaker 1: happens while the sheet bends right? Where you can imagine
11:25
Speaker 1: twisting a rubber sheet or or folding a rubber sheet over. Right,
11:30
Speaker 1: If you fold a rubber sheet over, then two parts
11:33
Speaker 1: which would be far apart if you moved along the sheet,
11:36
Speaker 1: could be very close to each other in that third dimension, right,
11:39
Speaker 1: Or if you roll it up right, imagine rolling up
11:42
Speaker 1: a two dimensional um sheet of space, then you have
11:45
Speaker 1: like a toilet paper roll or a toilet paper universe
11:48
Speaker 1: in which parts of the sheet are touching other parts
11:51
Speaker 1: of the sheet that are outside or inside on the roll,
11:54
Speaker 1: and then they're actually very close to each other. Oh
11:56
Speaker 1: you mean, like I can walk forward for a long
11:59
Speaker 1: time and I think I'm going straight, but really I'm
12:01
Speaker 1: going around and around this toilet paper. That's right. And
12:05
Speaker 1: a wormhole would be a connection that's not along the paper.
12:09
Speaker 1: It would be a more complex connection to be a
12:11
Speaker 1: connection from one um one roll around to the next roll,
12:15
Speaker 1: or to the to the inner roll, or to the
12:16
Speaker 1: more outer roll. Or if you imagine just a simple
12:19
Speaker 1: simple rubber sheet where you're folding it like a taco,
12:22
Speaker 1: it would be a connection between the two sides of
12:24
Speaker 1: the taco, and you can go the long way around
12:26
Speaker 1: by moving along the sheet. But a wormhole would be
12:29
Speaker 1: a more unusual connection, would be a connection that sort
12:32
Speaker 1: of shortcuts. And space can do these things, right. We
12:35
Speaker 1: know that space is more complicated than just emptiness, and
12:38
Speaker 1: it has a shape, and that shape can be complicated. Right.
12:41
Speaker 1: It can bend, it can stretch, you can wiggle, it
12:45
Speaker 1: can ripple. They could also just have strange connections to it. Right,
12:48
Speaker 1: you can connect two parts of space that are distant
12:51
Speaker 1: along one path, and you can make them very close
12:53
Speaker 1: together on other paths. Right. I thought of a great analogy.
12:57
Speaker 1: You know, how you when you're an how to do
12:58
Speaker 1: with the banana most it's yellow? Um, you know when
13:02
Speaker 1: you're in ikea and you're walking along and you're you know,
13:06
Speaker 1: watching all the furnit turn and stuff, and then suddenly
13:08
Speaker 1: you come upon like a here, here's a shortgut to
13:10
Speaker 1: betting or here's her shortgut to kitchen, and it's like,
13:14
Speaker 1: you're like, what what's going on? It's like the Ikea.
13:17
Speaker 1: It takes you in a path that curves around every
13:18
Speaker 1: every once in a while you can cut through some
13:20
Speaker 1: of these folds of your path. That's sort of like
13:23
Speaker 1: what a worm hall is, right, that's exactly right. And uh,
13:26
Speaker 1: some hot times when I'm in Ikea, I really wish
13:28
Speaker 1: I had a wormhole to just get me out of
13:30
Speaker 1: here immediately and send me home. Oh my god. Well,
13:33
Speaker 1: they really do kind of distort your spacetime in there
13:36
Speaker 1: that you never leave. It's like a casino. There's no
13:39
Speaker 1: outside windows. You can't tell if you've been there for
13:41
Speaker 1: ten minutes or ten hours. It's sort of a nightmare. Now,
13:43
Speaker 1: that's a that's a perfect analogy, um, And it shows
13:46
Speaker 1: you how there can be two paths to get to
13:48
Speaker 1: the same place, right, a long one and a short one.
13:51
Speaker 1: And the thing that's tricky for people to understand is
13:53
Speaker 1: how this space can be bent. And the problem with
13:56
Speaker 1: the analogy we talked about earlier bending of two dimensional
13:59
Speaker 1: space in the third dimension, right, it's that third dimension
14:02
Speaker 1: that helps you get from one place to the other
14:04
Speaker 1: because the bending is in that third dimension. So you
14:06
Speaker 1: have to be able to move in that third dimension
14:08
Speaker 1: or connect space in that third dimension. The problem with
14:11
Speaker 1: that analogy is that we don't think our three dimensional
14:15
Speaker 1: space is embedded in some four dimensional space. Right. The
14:19
Speaker 1: bending of space is not in some other higher fourth dimension.
14:23
Speaker 1: It's intrinsic, okay, rather than extrinsic. It's intrinsic. It's the
14:27
Speaker 1: relationship between points in space. It's not that the space
14:31
Speaker 1: itself is embedded in some four dimensional space that's twisting
14:34
Speaker 1: it like a three D rubber sheet. Right. It's all
14:37
Speaker 1: about the relationship between points in space. Right. But I
14:41
Speaker 1: guess the weird thing is to think about these forks
14:43
Speaker 1: in the road, right, like an I key, I'm walking around,
14:46
Speaker 1: walking forward, and suddenly I have two options. I can
14:49
Speaker 1: keep going on the loopy path, or I can take
14:52
Speaker 1: the shortcut to the next loop. Right, that's right? And
14:56
Speaker 1: so what does it mean to connect something in space
14:59
Speaker 1: for us? You know? Like, does that mean that I
15:01
Speaker 1: can either move to the side of myself or I
15:03
Speaker 1: can move a bazillion light years away if I move
15:07
Speaker 1: in a special direction. What does that mean to have
15:09
Speaker 1: two points connected? That are actually far away. It just
15:12
Speaker 1: means that there's two different paths with two different lengths
15:15
Speaker 1: to the same place. Right when you say that other
15:17
Speaker 1: point is a Brazilian light year was away, Yeah, it's
15:20
Speaker 1: a bazilion light years the way if you move through
15:21
Speaker 1: flat space, right, if you sort of like point yourself
15:24
Speaker 1: in that direction and go right. But um, there can
15:28
Speaker 1: be another path that's shorter. Right, But how do I
15:31
Speaker 1: choose those paths? Like, how do I choose to take
15:33
Speaker 1: the shortcut or not the shortcut? Well, there has to
15:36
Speaker 1: be a connection there, and that's where the wormhole is, right.
15:38
Speaker 1: A wormhole is that kind of connection. It's a connection
15:40
Speaker 1: between two parts of space which otherwise are far apart,
15:43
Speaker 1: to make them actually closer. And that's why earlier I
15:46
Speaker 1: was saying it's not teleportation. You're still just moving through space.
15:50
Speaker 1: If we define teleportation as moving to another location without
15:54
Speaker 1: moving through space, then a wormhole is not teleportation because
15:58
Speaker 1: you're still moving through space. You've just shrunk the distance
16:01
Speaker 1: you have to travel by bringing those two things closer together,
16:04
Speaker 1: by creating a path between them that's short. And the
16:08
Speaker 1: only way this is possible is if space can do
16:10
Speaker 1: these weird things. If space can twist and bend and
16:12
Speaker 1: and have bizarre shapes to it. M always see you're saying,
16:15
Speaker 1: teleportation is more like you disappear from here and you
16:18
Speaker 1: appear over there. But traveling through a warm hole is
16:23
Speaker 1: basically just um, just still traveling. You're still moving. It
16:26
Speaker 1: just so happens to be a shortcut, that's right. It's like,
16:29
Speaker 1: you know if you say, hey, can you teleport something
16:32
Speaker 1: from the fridge to the couch, and I like, you know,
16:35
Speaker 1: make a lasso, and I dragged the fridge over to
16:37
Speaker 1: the couch, and I'm like, hey, look, I don't have
16:39
Speaker 1: to get off the couch to get something out of
16:40
Speaker 1: the fridge anymore. That's not really teleportation, right, I've just
16:43
Speaker 1: brought the destination closer to me so that I can
16:46
Speaker 1: reach it without getting off the couch. Right, Although for
16:48
Speaker 1: me either way, you did it for me, so I'm happy.
16:52
Speaker 1: You're like, I don't care about the details. Just get
16:54
Speaker 1: me that drink, my next banana, right, I don't pay
16:58
Speaker 1: you to bother me with the details. Um. Yeah, And
17:01
Speaker 1: so it's a semantic distinction. I only I don't really
17:03
Speaker 1: usually care about semantic distinctions, but a lot of people
17:05
Speaker 1: were curious about why we didn't talk about wormholes in
17:07
Speaker 1: the teleportation episode. And that's why because in my mind,
17:10
Speaker 1: it's not really teleportation. Also, it's actually maybe possible, whereas
17:14
Speaker 1: teleportation is, like, you know, much more difficult. You're being
17:17
Speaker 1: a physics lawyer, Yes, I was being a physicist. That's
17:21
Speaker 1: sort of my job, is his lawyer. Before we keep going,
17:27
Speaker 1: let's take a short break. So, yeah, so that's a wormhole.
17:42
Speaker 1: It's connect It's like when you short circuit two point
17:45
Speaker 1: in space. That's right, Yeah, you bring them, you make
17:48
Speaker 1: you create a path between them. Um, a short path
17:51
Speaker 1: between two points that are otherwise really far apart. That's
17:54
Speaker 1: where a wormhole is. Yeah. So this seems to really fantastical.
17:58
Speaker 1: Is this real? Is this actually based on the laws
18:01
Speaker 1: of physics? That this is possible? It's an amazing idea, right,
18:05
Speaker 1: And the craziest thing about it is that it does
18:08
Speaker 1: follow the laws of physics. If you brought this concept
18:11
Speaker 1: to the International or the Intergalactic or the Universal Court
18:14
Speaker 1: of Physics, they would say, yeah, that's allowed. WHOA, what
18:19
Speaker 1: does that mean? How kind of how can the laws
18:21
Speaker 1: of physics allowed? Is? Well, you know, um, it violates
18:24
Speaker 1: our intuition and it seems really odd. But a lot
18:27
Speaker 1: of things in the universe violate our intuition and seem odd.
18:29
Speaker 1: And those are the most fun things, right, Those are
18:31
Speaker 1: the things that make physics so interesting. Um. But we
18:34
Speaker 1: say that it's theoretically allowed because we figured out some
18:37
Speaker 1: rules of the universe. Right. We watch the universe, We
18:40
Speaker 1: watch apples fall off trees, we see balls moving through
18:42
Speaker 1: the air, we watch planets go around suns, and we
18:45
Speaker 1: observes various things, and then we develop laws that describe them. Right.
18:49
Speaker 1: So in this case, we're talking about general relativity, right
18:51
Speaker 1: Einstein's field equations. That's say, here are the rules of
18:55
Speaker 1: how space can be bent. I remember general relativity described gravity,
19:00
Speaker 1: and gravity is not a force like other forces, and
19:03
Speaker 1: that we have like a quantum mechanical description of little
19:05
Speaker 1: particles being sent back and forth to transmit the force.
19:09
Speaker 1: As far as we know, gravity is a bending of space.
19:11
Speaker 1: And so general relativity tells us what are the rules
19:14
Speaker 1: for bending space? And there's a list of rules. Right,
19:17
Speaker 1: space can do this basically do that's basically do the
19:19
Speaker 1: other thing. So when we say is something theoretically allowed,
19:23
Speaker 1: what we mean is does it follow those rules, Right,
19:26
Speaker 1: And so the rules say that you can bend space
19:29
Speaker 1: so much that it comes around and kind of touches itself. Again,
19:33
Speaker 1: that's right, wormholes satisfy those equations. According to those equations,
19:38
Speaker 1: wormholes are allowed. And that that doesn't mean that wormsholes exist, right,
19:42
Speaker 1: It means that they are allowed. It's like saying, you know,
19:45
Speaker 1: before anybody had ever build a tesla, you might say,
19:48
Speaker 1: we'll do the laws of physics prevent anyone from building
19:50
Speaker 1: this awesome car. They can go two miles an hour
19:53
Speaker 1: and looks really cool. You might say, yeah, the laws
19:55
Speaker 1: of physics allow it, but nobody has ever built a
19:57
Speaker 1: tesla before. Right, In the same way, worm holes are
20:00
Speaker 1: allowed by the laws of physics. But that doesn't mean
20:02
Speaker 1: necessarily that there are any, right. And then, and black
20:06
Speaker 1: holes were also in this category for a long time, right, Like,
20:09
Speaker 1: we thought black holes were possible, but we had never
20:12
Speaker 1: absorved one or seen evidence of one. That's right. Black
20:16
Speaker 1: holes were just theoretical for a long time. And it
20:18
Speaker 1: came about exactly the same way. People were playing with
20:20
Speaker 1: the Einstein equations and saying, well, what's the weirdest thing
20:24
Speaker 1: we can get space to do? Right? One, can you
20:26
Speaker 1: can you do this, can do that, can do this
20:28
Speaker 1: other thing? And they found all these solutions to the equations. Right,
20:30
Speaker 1: a solution of the equation is a description of space
20:33
Speaker 1: that follows all those rules. And from the case of
20:36
Speaker 1: black holes, they figured out if you have a really,
20:38
Speaker 1: really dense object and you get this bizarre thing in
20:40
Speaker 1: space called a black hole. And it was decades before
20:43
Speaker 1: anybody actually observed one. It was for a long time
20:45
Speaker 1: people didn't know is this just theoretical, I mean, this
20:48
Speaker 1: is right, or is it something that's actually real, or
20:51
Speaker 1: is it just you know, is it proof that the
20:53
Speaker 1: equations are wrong? Right? It sort It seems like a bizarre,
20:57
Speaker 1: nonsensical prediction of the equations. And that's the kind thing
21:00
Speaker 1: we're always doing in physics. We're saying, let's take the
21:02
Speaker 1: equations we have, let's see what they predict, and let's
21:05
Speaker 1: go out and look to see if we can spot that.
21:07
Speaker 1: Because if you can spot it, it means probably more
21:09
Speaker 1: likely that the equations are right, and if we can't,
21:12
Speaker 1: then it means more likely the equations are wrong. And
21:14
Speaker 1: we keep finding these weird predictions of general relativity that
21:17
Speaker 1: turn out to be true. Black holes, gravitational waves, so
21:21
Speaker 1: when you say connects two points together in space, like
21:24
Speaker 1: like a shortcut, is it only a point or is
21:27
Speaker 1: it Could it be like a region of space is
21:29
Speaker 1: connected to another regional space or does it only work
21:31
Speaker 1: for little, tiny points. That's a great question. There's a
21:35
Speaker 1: few different varieties of wormholes. Most of them the opening
21:39
Speaker 1: is super duper tiny, and so if anything could even
21:42
Speaker 1: go through it, it would have to be like a
21:44
Speaker 1: single particle or a single photon or something. But there
21:47
Speaker 1: are some theories of wormholes where it could be bigger,
21:49
Speaker 1: you know, big enough for you to pass through or
21:50
Speaker 1: drive your car through, so you wouldn't have to sit
21:52
Speaker 1: on the four or five in traffic. Right. Well, what's
21:55
Speaker 1: the difference between these two types of theories? Like how
21:57
Speaker 1: can one predict a whole big tunnel? Well, and a
22:01
Speaker 1: lot of conceptions. A wormhole is sort of like a
22:03
Speaker 1: hole in space. It's like a If you actually found one,
22:07
Speaker 1: it would be like a three D object, right, not
22:09
Speaker 1: not a two D object. Would be like a sphere, okay,
22:12
Speaker 1: And if you went into that sphere, then you would
22:14
Speaker 1: appear in another place in space where you would space
22:18
Speaker 1: is connected through that sphere, right, So it would be
22:21
Speaker 1: like a really strange door, right, and you look at
22:24
Speaker 1: the sphere, you can see what's in that other part
22:27
Speaker 1: of space, and so it's more than just a point
22:29
Speaker 1: that can be larger. And so in theory you could
22:32
Speaker 1: you know, go through them. But as we can talk
22:35
Speaker 1: about that in a moment about the practicalities of making
22:38
Speaker 1: a wormhole and and and the limitations of them. So
22:41
Speaker 1: wormholes are theoretically possible, that's right. So there's nothing the
22:45
Speaker 1: loss of physics to say wormholes cannot exist. And that's
22:48
Speaker 1: just because space can do these weird things, right. It
22:50
Speaker 1: can do all these It can twist, it can bend,
22:52
Speaker 1: it can be strangely connected. You can only have a
22:55
Speaker 1: wormhole where spaces can of bent around and into itself, right.
23:00
Speaker 1: And then when these when the space kind of touches
23:01
Speaker 1: itself again, that's where the wormhole can happen. It's not
23:05
Speaker 1: like an actual tunnel that goes from one part of
23:08
Speaker 1: the toilet paper to another part of the toilet paper.
23:10
Speaker 1: It's like it's when space kind of touches itself again, right,
23:13
Speaker 1: that's right, you'd be traveling no distance. Right. One side
23:16
Speaker 1: of the wormhole is exactly the same as the other
23:18
Speaker 1: side of the wormhole. You know, there's not like a
23:21
Speaker 1: tunnel where like flashing lights and crazy stuff is happening. Um,
23:25
Speaker 1: it would be as you pass through, you're on one
23:28
Speaker 1: side of it and instantly you're on the other side.
23:29
Speaker 1: It's like zero length. Well, boy, that sounds great. So
23:32
Speaker 1: you don't have to pack any snacks? That was that?
23:35
Speaker 1: Was that the goal of your question? You have just
23:38
Speaker 1: in case you need to go fishing on the other side.
23:42
Speaker 1: That might be helpful. But yeah, they sound great. They
23:46
Speaker 1: sound like like it would cut down or travel time
23:48
Speaker 1: to other stars and like like you could just step
23:51
Speaker 1: through it and you wouldn't need to pack a lot
23:54
Speaker 1: or you have a lot of protection to in a
23:56
Speaker 1: space suit or spaceship. Right, it sounds pretty good. It
23:59
Speaker 1: does sound pretty good. And so for those folks out
24:02
Speaker 1: there who are now like googling how to travel to
24:04
Speaker 1: wormholes or you know, looking on kayak to book your
24:06
Speaker 1: wormhole ticket, maybe we should bring them down a notch
24:09
Speaker 1: and then talk about weather wormholes, Um, how wormholes work
24:13
Speaker 1: in reality? Alright, So unfortunately I have a long list
24:20
Speaker 1: of reasons here why you will never go through a wormhole.
24:23
Speaker 1: Wait me in particular or in particular I'm focusing on you, Horror.
24:27
Speaker 1: Everything I do is about you. I'm just I'm not
24:30
Speaker 1: skinny enough to fit through what You've been eaten too
24:35
Speaker 1: many bananas, I've noticed. Um. No, Problem number one is
24:38
Speaker 1: that nobody's ever found a wormhole, right, so we don't
24:41
Speaker 1: know if there are any out there. Um. And problem
24:44
Speaker 1: number one A is that even if wormholes are theoretically possible,
24:48
Speaker 1: we don't know how to make one, right. I mean,
24:51
Speaker 1: option one is find a wormhole and go in and
24:54
Speaker 1: see where you end up. Right. That's sort of like
24:56
Speaker 1: just getting on a random plane at the airport and
24:58
Speaker 1: having no idea if you're going to win us Iris
25:00
Speaker 1: or you know, Singapore. Right. Well, I guess the question
25:03
Speaker 1: is how would you find one? Like? What what would
25:06
Speaker 1: what would you look for? Yeah? So, well, how would
25:08
Speaker 1: you find a wormhole? It would be pretty tough, right.
25:11
Speaker 1: You'd need to sort of spotted the way we spotted
25:13
Speaker 1: black holes. Right. We spotted black holes by noticing that
25:16
Speaker 1: there was this black spot in space where if something
25:20
Speaker 1: passed behind it, it would disappear and no light was
25:22
Speaker 1: coming out from it. So for a wormhole, you need
25:25
Speaker 1: to see things going into it, right, But then it
25:27
Speaker 1: might just look like a black hole. So you need
25:29
Speaker 1: to see the other side also, and you need to
25:31
Speaker 1: see something coming out of it. So you need to
25:34
Speaker 1: see like particle a going in and then that same
25:36
Speaker 1: particle coming out the other side. That would be pretty tricky.
25:39
Speaker 1: You might find one edge of a wormhole and just
25:42
Speaker 1: think it's a black hole. Oh, until you found the
25:45
Speaker 1: other side. The one side of the wormhole just looks
25:48
Speaker 1: like a black hole. That's right. In fact, a lot
25:51
Speaker 1: of the theories of wormholes start from black holes. They
25:53
Speaker 1: say that, I am because a wormhole in a black
25:56
Speaker 1: hole are very similar, right. They both suck things in
25:59
Speaker 1: and then they constrict space down to a very narrow spot.
26:03
Speaker 1: The space is very dense inside them. Um, And so
26:06
Speaker 1: one side of a wormhole could just look like a
26:08
Speaker 1: black hole. Oh. Wormholes do the same thing as black holes.
26:11
Speaker 1: They look like a little like a pinch They pinched
26:14
Speaker 1: space around them, like they contract space leading up to
26:17
Speaker 1: exactly exactly. And you can think of a wormhole sort
26:20
Speaker 1: of like imagine whatever visualization you're using for a black
26:23
Speaker 1: hole in your head. Now, put two of those together
26:26
Speaker 1: with a little pinchy parts touch, and you had a
26:28
Speaker 1: sort of flares it like zooms in and then flares
26:31
Speaker 1: out again and sort of and on one side you
26:34
Speaker 1: have a black hole. On the other side you have
26:36
Speaker 1: this thing called a white hole move which is sort
26:40
Speaker 1: of the opposite of a black hole. And we should
26:42
Speaker 1: do like a whole podcast episode on white holes. But
26:44
Speaker 1: what you should know about white holes is that you
26:46
Speaker 1: can't enter a white hole, but stuff can leave, So
26:49
Speaker 1: it's sort of the opposite of a black hole in
26:51
Speaker 1: that sense. Now, no white hole has ever been seen.
26:53
Speaker 1: It's just a theoretical concept. But if a wormhole really
26:56
Speaker 1: did exist, it would be a black hole pair to
26:59
Speaker 1: the white hole. Oh, it's one directional. You can't use
27:01
Speaker 1: a wormhole two ways, not that we're aware of, right,
27:05
Speaker 1: So that's that's Problem number two is that wormholes are
27:07
Speaker 1: a one way trip, and so you might go into it,
27:10
Speaker 1: come out in Alpha centauri and be like, wow, I
27:13
Speaker 1: forgot to pack my underwear, and now it's too late.
27:15
Speaker 1: It's too late. You're going commanded for the rest of
27:17
Speaker 1: your galactic existence. That's right, um, But there are deeper
27:22
Speaker 1: problems with wormholes. Um. Problem number three is that wormholes,
27:26
Speaker 1: as far as we theoretically understand them, are very short lived.
27:29
Speaker 1: So if a wormhole is created, the equations of general
27:32
Speaker 1: relativity tell us that that pinching point would last very
27:36
Speaker 1: very briefly, and then they would snap, and then you
27:38
Speaker 1: just end up with a black hole in a white
27:40
Speaker 1: hole separated. What wouldn't be connected that general relativity doesn't
27:45
Speaker 1: like having a It's not a stable solution, all right.
27:48
Speaker 1: It's not something which can exist and and not change
27:51
Speaker 1: through time. The equations of general relativity say that um
27:55
Speaker 1: space space what doesn't like to be connected that way
27:58
Speaker 1: for very long. It's not the low energy configuration. And
28:01
Speaker 1: so if a wormhole is created by whatever means, then
28:05
Speaker 1: a space would relax by separating back into a black
28:08
Speaker 1: hole and in a white hole. Wait, so wormholes are
28:10
Speaker 1: not permanent like the curvature. You're talking about a space
28:14
Speaker 1: and space looping your on itself. It's constantly moving and changing.
28:19
Speaker 1: That's right. It's like a gravitational wave, right. It's not
28:21
Speaker 1: a permanent fixture in space. It's a wiggle. And so
28:24
Speaker 1: wormholes are like that. Wormholes can be created, though we
28:27
Speaker 1: don't know how, but they can be described by the
28:29
Speaker 1: equation of general relativity. But they don't last very long.
28:32
Speaker 1: They're very short lived. They're like, you know, momentarily existing.
28:36
Speaker 1: Oh boy, yeah, that's a problem. So we we can't
28:39
Speaker 1: find them and they don't last for very long. That's right,
28:42
Speaker 1: But some clever physicists thought up a way to maybe
28:45
Speaker 1: make wormholes last a little longer. I have so many
28:48
Speaker 1: questions for you, but before we dive in, let's take
28:51
Speaker 1: a short break. First of all, can we make wormholes?
29:07
Speaker 1: Is that theoretically possible? Like, can we build something that
29:10
Speaker 1: would make one? We have no idea. I mean, we
29:13
Speaker 1: know that the equations of general relativity allow them, but
29:15
Speaker 1: we don't know how to make a wormhole. Um. But
29:19
Speaker 1: if we did find a wormhole before it collapsed, some
29:22
Speaker 1: physicists worked out a way too to make it last longer.
29:26
Speaker 1: For it to be stable, all you need to do
29:29
Speaker 1: is stuff it filled with a huge amount of exotic matter,
29:32
Speaker 1: which is something we've never seen before and don't know
29:35
Speaker 1: if it exists. But if you could create a huge
29:37
Speaker 1: amount of it and stuff it inside a wormhole, then
29:40
Speaker 1: theoretically you might be able to stabilize the wormhole. Now,
29:43
Speaker 1: exotic matter is this weird stuff that has negative mass,
29:48
Speaker 1: and you need something with negative mass because it would
29:50
Speaker 1: have sort of the opposite gravitational effect of normal mass.
29:54
Speaker 1: Normal mass pull stuff together, negative mass would be pushing
29:57
Speaker 1: stuff apart. So you stuff that inside the wormhole, it
30:00
Speaker 1: was sort of hold it open. So if you could
30:03
Speaker 1: find this special impossible mass, and you could also find
30:06
Speaker 1: a wormhole and you could throw it in there, it
30:09
Speaker 1: might keep the wormhole open for more than that's right,
30:13
Speaker 1: But I wouldn't go in there with your kids. On
30:16
Speaker 1: the guessing of a bunch of businesses. You could throw
30:19
Speaker 1: some bananas in there first, that's right. And you know
30:23
Speaker 1: the other problem with wormholes is they might be super
30:25
Speaker 1: duper small, right, Even these wormholes were talking about could
30:28
Speaker 1: be like plank length size, like ten to the minus
30:31
Speaker 1: thirty five wide. Wait, do you mean like the size
30:34
Speaker 1: of something that would fit in a wormhole? Is that small?
30:37
Speaker 1: That's right. We don't really know, but some theories say
30:39
Speaker 1: that wormholes would have to be super duper tiny if
30:41
Speaker 1: they exist at all. Right, So that's another disappointing fact.
30:45
Speaker 1: And and also the the idea about stuffing it full
30:48
Speaker 1: of exotic matter. That would hold the wormhole open, but
30:51
Speaker 1: it would also mean you can't go through it, because
30:54
Speaker 1: as soon as any sort of normal matter went through
30:56
Speaker 1: it, it it would disrupt it, and then the wormhole would collapse.
30:58
Speaker 1: So it might be that the wormholes exist, and it
31:01
Speaker 1: might be that you can hold them open with exotic matter,
31:03
Speaker 1: but then you couldn't go through them, which makes them
31:06
Speaker 1: sort of pointless because as soon as you go in
31:08
Speaker 1: it would close, or yeah, exactly as soon as you
31:12
Speaker 1: go in then it would collapse. So like totally might
31:15
Speaker 1: make it through, but then it'll collapse, and then you
31:17
Speaker 1: don't have any that's right, And then we haven't even
31:20
Speaker 1: talked about like the dangers of approaching anything that looks
31:24
Speaker 1: like a black hole. I mean, the gravitational forces are tremendous.
31:27
Speaker 1: You get anywhere close to a black hole, you're not
31:28
Speaker 1: going to get into it. You're gonna get shredded by
31:31
Speaker 1: the title forces before you get very close. So there's
31:34
Speaker 1: a lot of practical problems with using a wormhole, but
31:38
Speaker 1: so weird wire wormholes one directional. That's one thing I
31:41
Speaker 1: didn't quite yet. How does the universe decide which ways
31:43
Speaker 1: in and which ways out? Well, um, that's a good question.
31:47
Speaker 1: I don't know. We don't know how to make them,
31:48
Speaker 1: so we don't know what process determines their directionality. Yeah,
31:52
Speaker 1: it's a good question. But the but the physics say
31:54
Speaker 1: the mass says that they are one direction. That's right,
31:57
Speaker 1: And so let me add an important qualifier. We've been
31:59
Speaker 1: saying this whole time that they are theoretically possible. That's
32:02
Speaker 1: true according to general relativity. General relativity, as far as
32:05
Speaker 1: we note, is true. But we also know that general
32:09
Speaker 1: relativity is not quantum mechanical, right, that it cannot describe
32:14
Speaker 1: microscopic things very well, things where the quantum description of
32:17
Speaker 1: the universe takes over, where particles have fixed amounts of
32:21
Speaker 1: energy and are divided up into concrete chunks. Right, general
32:24
Speaker 1: relativity thinks of the universe is continuous and infinitely divisible,
32:28
Speaker 1: but we know it's not that. Most of the time,
32:30
Speaker 1: that's not a big deal because we're dealing with macroscopic objects.
32:33
Speaker 1: But when you're talking about the inside of black holes
32:35
Speaker 1: or the inside of wormholes, we're pretty sure that quantum
32:38
Speaker 1: effects are going to be important, which means that if
32:41
Speaker 1: you're gonna go inside a wormhole, you shouldn't just check
32:43
Speaker 1: with general relativity. You need to check with quantum gravity,
32:46
Speaker 1: which is the theory we don't even have. So I
32:48
Speaker 1: would be very wary of going inside a wormhole, even
32:51
Speaker 1: if you found one, even if you stabilized it, because
32:54
Speaker 1: we don't really know what the rules are of quantum gravity, right,
32:57
Speaker 1: and the hardest part seems to be to stand quantum physics.
33:02
Speaker 1: It's pretty tricky. Yeah, you gotta be pretty smart to
33:04
Speaker 1: understand quantum physics, I'll admit. Okay, So to answer the question,
33:11
Speaker 1: can we use a wormhole to get to another star galaxy?
33:14
Speaker 1: The answer is maybe, probably not theoretically possible, but it
33:22
Speaker 1: seems practically impossible. I would be super impressed with the
33:25
Speaker 1: next generation of engineers if we managed to build useful
33:29
Speaker 1: wormholes in the next hundred years or so, I would
33:32
Speaker 1: be very, very deeply impressed. Good job, guys, I think
33:36
Speaker 1: you'd probably be dead. They'll probably send me as an
33:40
Speaker 1: experimental subject through the first wormhole just to prove them wrong. Um. Yes,
33:44
Speaker 1: so I would say. The takeaway is wormholes theoretically possible
33:47
Speaker 1: but never been seen, and also very impractical. Right. But
33:51
Speaker 1: let's carry the fantasy a little bit longer here, because
33:53
Speaker 1: I heard I read that they wormholes might not just
33:57
Speaker 1: connect space, but they could also connect space and time.
34:01
Speaker 1: That's right, Space is part of this constructor called space
34:04
Speaker 1: time right where time is sort of the fourth dimension.
34:07
Speaker 1: And um, people have crazy ideas with what you could
34:09
Speaker 1: do with wormholes if you found them. If you take
34:12
Speaker 1: one end of the wormhole and you accelerated to really
34:14
Speaker 1: really high speeds, then you can take advantage of time dilation. Right,
34:18
Speaker 1: that's moving clocks run more slowly. Um. But if you're connected,
34:23
Speaker 1: if you have a stationary point connected to the fast
34:26
Speaker 1: moving point, that you can play all sorts of tricks
34:28
Speaker 1: with special relativity and maybe even go back in time.
34:32
Speaker 1: But Stephen Hawking says that's impossible. He says that if
34:36
Speaker 1: you send anything through the wormhole that the wormhole will collapse.
34:39
Speaker 1: And so they called this the chronological protection conjecture, with
34:44
Speaker 1: the universes like conspired to make the laws of physics
34:46
Speaker 1: impossible to do time travel. And I said, I took
34:50
Speaker 1: a stand on our time travel episode. I said time
34:52
Speaker 1: travel is impossible, and I stick by that because I
34:55
Speaker 1: think that this concept of using wormholes and trail back
34:57
Speaker 1: in time is absurd, not just impractical, but absurd and illogical. Okay,
35:02
Speaker 1: so sorry to rain on your parade, to to to
35:04
Speaker 1: prick your fantasy there, Jorge, let me throughout my idea
35:07
Speaker 1: for a sci fi novel right here. I'm just gonna
35:09
Speaker 1: I'm just gonna crush that out and put it in
35:11
Speaker 1: the trash here. No, no, science fiction is totally allowed, totally.
35:14
Speaker 1: You let in your universe. You can make up whatever
35:17
Speaker 1: rules you want as long as you follow them, so
35:19
Speaker 1: we can have that in your science fiction universe, no problem.
35:22
Speaker 1: All right, I guess until then we have to sit
35:23
Speaker 1: in traffic until the engineers figure out the wormhole. That's right,
35:28
Speaker 1: And so we hope you enjoyed this episode of Daniel
35:30
Speaker 1: and Jorge and um explain the universe and Daniel moorehe
35:34
Speaker 1: shoot down your sci fi idea. That's right, and try
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Speaker 1: send me your sci fi idea through the wormhole of
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Speaker 1: the internet, and I'll tell you why it's wrong, but
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Speaker 1: in a very cheerful tone. That's right. Warm your way
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Speaker 1: into Daniel's inbox. All right. Thanks to everyone, have a
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Speaker 1: good one, see you next time. If you still have
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Speaker 1: a question after listening to all these explanations, please drop
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Speaker 1: us a line. We'd love to hear from you. You
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Speaker 1: can find us at Facebook, Twitter, and Instagram at Daniel
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Speaker 1: and Jorge as one Word, or email us at Feedback
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Speaker 1: at Daniel and Jorge dot com,