Latest / Daniel and Kelly’s Extraordinary Universe / What's Inside a Black Hole?

Transcript

What's Inside a Black Hole? · Daniel and Kelly’s Extraordinary Universe

0:04
Speaker 1: Sometimes science comes up with the worst name for things
0:07
Speaker 1: they discover. I know, like killer whales, which aren't killer
0:12
Speaker 1: and are not actually whales, they're actually dolphins. Excellent point.
0:17
Speaker 1: But I was actually thinking about black holes. Okay, that's
0:20
Speaker 1: one of my favorite space names. What's round with black holes?
0:23
Speaker 1: It's an awesome name. But black holes aren't totally black
0:26
Speaker 1: and they're not actually holes. Their dolphins, all right? Who
0:31
Speaker 1: runs the science pr department here? I think it's run
0:35
Speaker 1: by a bunch of dolphins, a bunch of killer dolphins.
0:39
Speaker 1: So long and thanks for all the fish. We're heading
0:42
Speaker 1: to the black hole. Hi. I'm Jorge and I'm Daniel,
0:56
Speaker 1: and this is Daniel and Jorge. It's explain the Universe today.
1:00
Speaker 1: We're going to ask the question what is inside a
1:08
Speaker 1: black hole? Maybe the deepest, darkest mystery in the universe.
1:12
Speaker 1: But first, as usual, we went around and asked people
1:15
Speaker 1: on the street what do they know about black holes
1:17
Speaker 1: and what's hiding inside them. Here's what they had to say.
1:20
Speaker 1: A bunch of destroy destroyed matter and energy. I don't
1:25
Speaker 1: know exactly what's inside, but like it like captures light,
1:30
Speaker 1: and it has a gravity so like strong that like
1:35
Speaker 1: after a certain point you can't escape it Isn't it
1:37
Speaker 1: like a vacuum? The anti universe, I don't know. Holy moly,
1:43
Speaker 1: I love some of those answers the anti universe. It
1:46
Speaker 1: seems like most people kind of had had had a
1:49
Speaker 1: good idea of what a black hole was, right, Like
1:50
Speaker 1: a lot of people knew it was like a dance mass, right, Yeah,
1:53
Speaker 1: it's like a gravitational trap things can't escape from. People
1:57
Speaker 1: seem to have the basics out there, right that they're ends,
2:00
Speaker 1: they're dark, and things can't escape from them. Right, But
2:03
Speaker 1: nobody named knew what's inside of one. That's right. Nobody
2:06
Speaker 1: could tell us what was inside a black hole. Apparently
2:08
Speaker 1: just walking around in the street isn't the best way
2:11
Speaker 1: to get a solid scientific answer. But anyway, it's a
2:14
Speaker 1: black hole. So I guess you know, before we talked
2:16
Speaker 1: about what's inside a black hole, we should still recap
2:19
Speaker 1: what is a black hole? Yeah? What is a black hole?
2:21
Speaker 1: Black Holes are sort of fascinating ideas because for a
2:25
Speaker 1: long time people thought black holes were just sort of
2:27
Speaker 1: like a mathematical curiosity, like the kind of thing that
2:30
Speaker 1: you see in an equation. Then if you believe that
2:33
Speaker 1: equation describes reality, then it suggests black holes might exist.
2:37
Speaker 1: But it's the kind of thing that makes you wonder,
2:39
Speaker 1: is this really true or it's just so sort of
2:41
Speaker 1: like a weird feature of the equation, something people are
2:43
Speaker 1: not going to actually discover. What do you mean, like
2:46
Speaker 1: this is the origin of the idea of black holes,
2:48
Speaker 1: Like it was actually a theory first wasn't observed or
2:51
Speaker 1: anything exactly. The idea of black holes came from general relativity,
2:55
Speaker 1: and it wasn't observed for decades later. In fact, Albert
2:58
Speaker 1: Einstein thought black holes would never or be seen. He
3:00
Speaker 1: thought they didn't really exist, even though his theory predicted them.
3:03
Speaker 1: What did the theory predict. Einstein's basic idea is that
3:07
Speaker 1: gravity is not a force like other forces things that
3:10
Speaker 1: pull and push on each other, like electromagnetism and the
3:13
Speaker 1: weak force. He thought gravity instead was just a bending
3:17
Speaker 1: of space time that his idea was any mass which
3:21
Speaker 1: is sort of bend space. So imagine like a rubber
3:23
Speaker 1: sheet spaces that rubber sheet, you put something big and
3:26
Speaker 1: heavy on it, it bends things down. Now, if you
3:29
Speaker 1: want to marble, you roll marble across that sheet instead
3:31
Speaker 1: of just going flat across the sheet. If it encounters
3:35
Speaker 1: someplace where the sheet is bent, it's going to change
3:37
Speaker 1: its path. So the marble thinks it's going straight. But actually,
3:40
Speaker 1: like the rubber it's it's on is curved. That's right.
3:44
Speaker 1: It's that the most direct path is now curved with
3:47
Speaker 1: respect to your previous path. And that's a tricky concept
3:50
Speaker 1: for people to understand that. It's the bending of space,
3:53
Speaker 1: and it's the sort of intrinsic bending. It changes the
3:57
Speaker 1: natural straight lines. Um. But I love how you say
4:00
Speaker 1: the marble thinks it's going straight, Like you have this
4:02
Speaker 1: tendency to anthromorphize everything, like we were talking about that
4:05
Speaker 1: last time. In this case, like the marble has an
4:07
Speaker 1: opinion like, hey man, I'm going straight. I don't care
4:10
Speaker 1: what space says. Cartoon is I imagine that you look
4:14
Speaker 1: at the world and see little cartoon thought bubbles on everything.
4:17
Speaker 1: That's my world. So we were talking about very heavy objects.
4:24
Speaker 1: So the idea is very heavy masses bend space. Right,
4:27
Speaker 1: the bend space so that when you move through space,
4:29
Speaker 1: you end up moving through a curved path. Right, and
4:32
Speaker 1: Einstein and some then some later folks realized that there
4:36
Speaker 1: are some solutions to the general relativity equations where space
4:40
Speaker 1: has bent so much that you can imagine it's like
4:42
Speaker 1: a bottomless hole in that rubber sheet, so the things
4:45
Speaker 1: can never escape them. And Einstein and these other folks
4:49
Speaker 1: they discover these features the equations, but they were like,
4:52
Speaker 1: is this real? You know? And this goes to the
4:54
Speaker 1: heart of some of the stuff I love, like the
4:56
Speaker 1: connection between physics and math, right, we like we use
4:59
Speaker 1: math as a language of physics to describe the universe,
5:03
Speaker 1: and sometimes the math takes this in directions where we're like, no,
5:06
Speaker 1: that doesn't really work here. The math is not physical, right, Well,
5:09
Speaker 1: like throw away mathematical ideas that we say are not
5:12
Speaker 1: physical because they don't describe what actually happens. Sometimes the
5:16
Speaker 1: math describes something which we think is unphysical it turns
5:19
Speaker 1: out to be real and that's that's what happened here,
5:21
Speaker 1: which is pretty cool. Well. Um, so the math predicted
5:24
Speaker 1: that if you you might have a situation where we
5:26
Speaker 1: have so much mass in such a small space that
5:29
Speaker 1: will distort space so much that it will sort of
5:33
Speaker 1: create almost like a hole in space. Yeah, like a
5:36
Speaker 1: bottomless hole in this rubber sheet, so that even light
5:39
Speaker 1: which travels you know, the fastest thing in the universe. Um,
5:42
Speaker 1: can't escape because the all the straight line paths are closed. Now. Wow,
5:47
Speaker 1: So like you're so dabbed down into the whole of
5:50
Speaker 1: the barberschee, you'd have to be pointing up basically to
5:53
Speaker 1: get out. There's no path out. Yeah, exactly. Um, you
5:56
Speaker 1: know those big funnels they have in lots of science museums.
5:59
Speaker 1: You can put a penny in and it rolls around.
6:01
Speaker 1: It goes faster and faster and faster than it drops
6:03
Speaker 1: down to the hole. You can think of it sort
6:05
Speaker 1: of like that, but imagine that when you're down in
6:07
Speaker 1: the hole, right, there's no way for the penny to
6:09
Speaker 1: roll up and out of that hole. Right, Okay, So
6:11
Speaker 1: so that so it started off as a mathematical weird case,
6:16
Speaker 1: right for Einstein, and he was a smart guy, but
6:19
Speaker 1: he didn't think that that could actually exist in real life. Yeah,
6:22
Speaker 1: he thought it wouldn't actually happen because he thought that
6:25
Speaker 1: everything spins and because things spin, it it's harder for
6:29
Speaker 1: them to collapse. Right. You can think of most of
6:32
Speaker 1: the stuff in the universe as sort of a battle
6:34
Speaker 1: between gravity and some sort of pressure keeping it from collapsing.
6:39
Speaker 1: Like gravity wants to suck stuff together, rightsh them together. Yeah,
6:44
Speaker 1: it's weak, but you give it enough time, it's going
6:45
Speaker 1: to pull things together and make them tighter and denser
6:47
Speaker 1: and denser. So you might ask, well, why isn't everything
6:51
Speaker 1: in the universe a black hole? Like it's fourteen billion
6:53
Speaker 1: years in the gravity has had a lot of time.
6:56
Speaker 1: You know, why is the Sun not a black hole?
6:58
Speaker 1: Or why is the Earth not a black cool? Because
7:00
Speaker 1: gravity has compressed them. Um. And the answer in many
7:03
Speaker 1: cases is that they're spinning, and the spinning provides a
7:07
Speaker 1: sort of a rotational pressure. Think about what happens when
7:10
Speaker 1: you're standing on a merry go round, right, Um, somebody
7:13
Speaker 1: spins it, you can get thrown off the merry go round.
7:16
Speaker 1: And so that's sort of rotational pressure that keeps you
7:19
Speaker 1: from getting sucked in. And our galaxy and the Sun
7:22
Speaker 1: and the Earth, all these things are spinning, and it
7:25
Speaker 1: does make it harder to become a black hole. And
7:27
Speaker 1: so Einstein thought that there's no way you could ever
7:29
Speaker 1: see this because things were spinning, and that we wouldn't
7:32
Speaker 1: ever actually see a black hole would be impossible for
7:35
Speaker 1: them to create. He thought gravity could never actually crunch
7:38
Speaker 1: anything down that's small, because at that size things would
7:42
Speaker 1: sort of spin outwards more than gravity could crunch them in.
7:46
Speaker 1: But then he was proven wrong, Like, we actually saw
7:48
Speaker 1: black holes. That's right, and I want to talk a
7:51
Speaker 1: little bit more about that, but first a quick break. Yeah, so, um,
8:07
Speaker 1: we should talk about how you can see a black hole. Right.
8:10
Speaker 1: I imagine you see like a little black dot or
8:12
Speaker 1: a black circle in the sky or something. So a
8:15
Speaker 1: black hole is so heavy that light can't escape it,
8:18
Speaker 1: and that means that it doesn't reflect any light. Right,
8:21
Speaker 1: you shot a flashlight on it, no light comes back. Right,
8:24
Speaker 1: you shot a spotlight on it, shot a laser on it,
8:26
Speaker 1: shown anything on it, No light comes back. Even if
8:29
Speaker 1: there has the sun next to it, who won't bounce off.
8:32
Speaker 1: That's right. No light reflects, and it also doesn't admit
8:35
Speaker 1: any light. Now, there's a tiny asterisk we should talk
8:38
Speaker 1: about later, which is called hawking radiation. Turns out, black
8:41
Speaker 1: holes do give off a little bit of energy, but
8:43
Speaker 1: you can't really see it. So from the point of
8:45
Speaker 1: view was seeing a black hole, it's basically invisible. It's
8:49
Speaker 1: just like a black circle, right, So how could you
8:51
Speaker 1: possibly see that a black hole is there? Well, you know,
8:54
Speaker 1: I watched the movie Interstellar, which I know could be
8:57
Speaker 1: a whole topic of conversation, but that your research for
9:00
Speaker 1: the podcast. That and I read the Wikipedia page for
9:03
Speaker 1: the black Hole movie, which is a classic seventies movie.
9:06
Speaker 1: Did you ever watch the movie? Yes? It did. In fact,
9:08
Speaker 1: I saw that movie a few weeks ago with my kids.
9:11
Speaker 1: No way, really. I think it was supposed to be
9:13
Speaker 1: like a response to Star Wars or something, um and
9:17
Speaker 1: it's much weirder than Star Wars. According to Wikipedia, it's
9:22
Speaker 1: like the first Disney movie ever to get a PG rating.
9:25
Speaker 1: My kids were like, why did you show us this movie?
9:30
Speaker 1: Was this supposed to be good? Or is this educational?
9:32
Speaker 1: But this that movie was a huge part of my childhood,
9:35
Speaker 1: you know. It was like made a huge impression on me.
9:37
Speaker 1: You saw the black Hole movie as a kid? Yeah,
9:40
Speaker 1: you didn't see this again? You might have been the
9:41
Speaker 1: only one. I don't think it was very It was
9:44
Speaker 1: huge in Panama. What are you talking about? Huge in Panama?
9:47
Speaker 1: I rest my kids. Yeah, let's hope this podcast is
9:51
Speaker 1: huge in Panama. Let's hope we we achieved that level
9:54
Speaker 1: my fellow Panamanians. I hope they're listening. So how could
9:58
Speaker 1: you actually see a black hole? Let's shift out of
10:00
Speaker 1: the fictional world and back into the what we imagined
10:02
Speaker 1: to be the real world. How could you see a
10:04
Speaker 1: black hole? Well, it's biggest to funding feature is it's gravity,
10:07
Speaker 1: and so it has very powerful gravity, and you can
10:10
Speaker 1: see the effect of gravity on nearby stuff. So, for example,
10:14
Speaker 1: one of the biggest black holes that's near us is
10:16
Speaker 1: at the very center of the Milky Way. There's an
10:18
Speaker 1: enormous black hole there. It's huge. It's called super massive
10:23
Speaker 1: and um that's the category of black hole. And we
10:26
Speaker 1: can see that it's there because we see stars orbiting it.
10:29
Speaker 1: So we see the path of stars that are going
10:31
Speaker 1: around the black hole, so we can tell these stars
10:35
Speaker 1: are orbiting something, but we see nothing there. So you
10:38
Speaker 1: can do the calculations. You can say, oh, all these
10:41
Speaker 1: stars orbits are consistent with something really heavy here. Like
10:45
Speaker 1: imagine you were looking at the Solar System and you
10:48
Speaker 1: couldn't see the Sun. You could guess that there was
10:50
Speaker 1: something really massive there because see, look all these planets
10:53
Speaker 1: they are going around and they're all consistent with orbiting
10:56
Speaker 1: one thing that's really heavy, and you can even calculate
10:58
Speaker 1: its mass from the orbits and all that stuff. You
11:00
Speaker 1: could deduce that the Sun was here without actually seeing it.
11:03
Speaker 1: That would be a pretty silly way to see the sun.
11:06
Speaker 1: But you could definitely tell. And we can use that
11:08
Speaker 1: same approach, and we have to see the huge black
11:10
Speaker 1: hole in the center of the Milky Way for example.
11:12
Speaker 1: I see. Maybe that's the problem is that the closest
11:15
Speaker 1: black holes to us is at the center of the
11:18
Speaker 1: Milky Way galaxy. Now that's the closest, really big one.
11:21
Speaker 1: It's like twenty seven thousand light years. I think that's
11:24
Speaker 1: pretty far away. There are closer black holes to us
11:27
Speaker 1: than the one at the center of the Milky Way,
11:28
Speaker 1: but they're not as large, I see. But there's a
11:31
Speaker 1: theory about what they sort of look like, which is
11:33
Speaker 1: like a black ball, right, yeah, and there's other stuff
11:36
Speaker 1: near the black hole, right Like say, for example, you
11:39
Speaker 1: have a black hole and it's near a star. What's
11:42
Speaker 1: it gonna do. It's gonna shred the star. It's gonna
11:44
Speaker 1: suck all the stuff out of the star into the
11:46
Speaker 1: black hole. And you can see that also before stuff
11:50
Speaker 1: falls into the black hole, you can see it like
11:52
Speaker 1: on the way you know. Um, So for example, imagine
11:55
Speaker 1: there's like a you know, a hole in the sidewalk
11:57
Speaker 1: and everybody's falling into it. If you notice that trail
12:00
Speaker 1: of people walking along the sidewalk and then nothing on
12:03
Speaker 1: the other side, Oh my gosh. Exactly. So there's lots
12:09
Speaker 1: of black holes where you can see the stuff falling
12:11
Speaker 1: into it because it and sometimes it's like orbit once
12:14
Speaker 1: or twice before it falls in. This this thing called
12:16
Speaker 1: the accretion disk, which is like the stuff orbiting the
12:19
Speaker 1: black hole before it comes in. And so a lot
12:22
Speaker 1: of times you can see that around the black hole. Um,
12:25
Speaker 1: it's sort of like a warning, like, you know, abandoned,
12:27
Speaker 1: hope all you who fly near here because you are
12:30
Speaker 1: entering the black hole. But that also brings up another
12:33
Speaker 1: really interesting point, which is like a black hole is
12:36
Speaker 1: not a hole. You know, it's a clever name and
12:38
Speaker 1: it sounds awesome, and it's connects to this sort of
12:41
Speaker 1: geometric idea of like having a hole in the bottom
12:43
Speaker 1: of the rubber sheet. But I think most people think
12:46
Speaker 1: of a black hole is like a hole in space,
12:48
Speaker 1: like something you could fall into, right, But as you
12:52
Speaker 1: said earlier, a black hole is something that's really dense,
12:55
Speaker 1: it's really heavy, it's really thick. You can't fall into it.
12:58
Speaker 1: It's more like a black Man as sort of like
13:00
Speaker 1: a black rock. You know, it's like saying, can you
13:03
Speaker 1: fall into the earth? Right, Like, you can't fall into
13:06
Speaker 1: the earth, you fall onto the earth. Right. Well, you're
13:08
Speaker 1: sort of assuming you know what's inside a black hole? Right? Well,
13:11
Speaker 1: we know it's really dance, right, we know there's a
13:13
Speaker 1: lot of stuff in there. But in terms of like space,
13:16
Speaker 1: like space is so distorted. It's sort of like a hole,
13:19
Speaker 1: isn't it. It's like the rubber sheet analogy. It is
13:22
Speaker 1: sort of a like a three D hole. It's like
13:24
Speaker 1: it's through a hole in three D space. Right, it's
13:27
Speaker 1: a gravitational well that you can't climb out of. But
13:30
Speaker 1: that doesn't mean that it's like empty inside. You can
13:32
Speaker 1: like once you go in, you can like dance all
13:34
Speaker 1: around is playing the room. Let's think about that this
13:38
Speaker 1: sort of where is the edge of the black hole?
13:39
Speaker 1: And a lot of people think of the edge of
13:41
Speaker 1: the black hole as something we call the event horizon. Okay,
13:44
Speaker 1: what's the event horizon? Besides being a bad science fiction
13:47
Speaker 1: movie with Sam Neil, the Event Horizon is another movie.
13:53
Speaker 1: I see you're not up on your bad sighest fiction cinema.
13:56
Speaker 1: Did this? Did this? Only come out in Panama. No,
13:58
Speaker 1: this was a real movie. It had like fishburn I
14:00
Speaker 1: think Sam Neil. It was like a big deal. But anyway, so,
14:06
Speaker 1: what is the event horizon of a black hole? Yeah,
14:09
Speaker 1: so that's the point after which you can't escape, right,
14:11
Speaker 1: if you are closer to the center of the black
14:14
Speaker 1: hole than the than this threashold you can't escape. Outside
14:18
Speaker 1: of that, there's still a possibility. Inside there are no paths.
14:21
Speaker 1: It's like, you could escape if you could move faster
14:23
Speaker 1: than light. But even if you were like moving at
14:26
Speaker 1: the speed of light, you could not escape. But be
14:28
Speaker 1: careful because people like to say, oh, maybe if you
14:31
Speaker 1: went faster than the speed of light, blah blah blah.
14:33
Speaker 1: But going faster than the speed of light, that's a
14:35
Speaker 1: whole other podcast we should do. Right, it's impossible, And
14:38
Speaker 1: so saying something like going fast in the speed of
14:41
Speaker 1: light is like saying like, well, then if you had magic,
14:43
Speaker 1: then sure all the rules would be off. So like
14:46
Speaker 1: an interstellar when they shared the black hole, is this
14:48
Speaker 1: black sphere, that's the event horizon, right, that's like the
14:52
Speaker 1: edge of that sphere black circle is the event horizon
14:56
Speaker 1: because anything inside would just look black. So Is this
14:58
Speaker 1: a PHY six podcast asked or a film podcast? Film
15:03
Speaker 1: six podcast? No? But I mean, I guess you know what.
15:07
Speaker 1: The reason I bring it up is that, you know,
15:08
Speaker 1: I think a lot of people have heard of the
15:10
Speaker 1: event of horizon, right, and the conceptually what it is
15:14
Speaker 1: you can't escape after that, but like a representation of
15:17
Speaker 1: a black hole, that that circle is kind of the
15:20
Speaker 1: event horizon, right, Yeah, you're exactly right. And so you
15:22
Speaker 1: would see like the accretion disk around the black hole,
15:25
Speaker 1: the stuff that's about to fall in, like what's on
15:27
Speaker 1: deck to get sucked up by the black hole. But
15:29
Speaker 1: you're right, the black hole itself would be black, and
15:31
Speaker 1: that's the event horizon. You're seeing the edge because you
15:34
Speaker 1: can't see anything in it, nothing can escape it, and
15:37
Speaker 1: so it's surrounded by matter which you can normally see.
15:40
Speaker 1: But the actual black hole itself is the edge of
15:42
Speaker 1: the event horizon, and that's what that's what makes the
15:45
Speaker 1: questions how interesting. Because you can't see in there, people
15:47
Speaker 1: wonder what's in there? Right. Einstein's original idea was that
15:51
Speaker 1: there was something called a singularity that's a point of
15:54
Speaker 1: essentially infinite density at the very center of it. Right,
15:58
Speaker 1: that's right, Yeah, an infinite least small space, right, super
16:02
Speaker 1: super dense. As soon as you cross some threshold of
16:04
Speaker 1: mass density, then you've created this hole in the bottom
16:08
Speaker 1: of the rubber sheet, a gravitational well that nothing can escape.
16:12
Speaker 1: But it's not necessary that the whole event horizon is
16:15
Speaker 1: filled in with mass. I think this is the point
16:17
Speaker 1: you were trying to make earlier. There's got to be
16:19
Speaker 1: a dense core in there somehow, but it creates a
16:22
Speaker 1: gravitational well that's larger than that core um. And so
16:26
Speaker 1: this is the original idea in stands. Original idea was
16:29
Speaker 1: that there's this singularity, this really really dense point. Okay,
16:32
Speaker 1: so maybe a black hole is like some kind of
16:34
Speaker 1: point surrounded by who knows, but it sort of goes
16:38
Speaker 1: out to the sphere of blackness. That's going to be
16:41
Speaker 1: the name of our band, right, Sphere of Blackness or
16:46
Speaker 1: my next Panamanian bad sci fi movie. I think that's
16:49
Speaker 1: a la. There's so many concepts tied together into a
16:55
Speaker 1: black holes. But I think people still wonder what's inside
16:58
Speaker 1: a black hole because we're pretty sure that this idea
17:01
Speaker 1: of a singularity can't be right, pretty sure that there
17:04
Speaker 1: aren't singularities inside black So not even our theory about
17:08
Speaker 1: what's inside is right, yeah, And you know, Einstein's theory
17:12
Speaker 1: is wonderful and it's beautiful, and it's predicted lots of
17:15
Speaker 1: stuff which seemed weird but actually happens, like gravitational waves. Right.
17:20
Speaker 1: Einstein predicted gravitational waves, these ripples in space time when
17:24
Speaker 1: massive objects slam into each other or spin around each
17:27
Speaker 1: other a hundred years before we saw them, right or
17:30
Speaker 1: hurt them as yeah, yeah, decades and decades, I don't
17:34
Speaker 1: remember the exact date, but a long time before we
17:36
Speaker 1: saw them. And the problem with Einstein's theory is that
17:39
Speaker 1: it doesn't include any quantum mechanics. And that's because we
17:42
Speaker 1: figured out quantum mechanics sort of at the same time
17:44
Speaker 1: or in the decades after general relativity. And something really
17:48
Speaker 1: important about quantum mechanics is that it doesn't allow things
17:51
Speaker 1: to be located in infinitely small spaces. There's a basic
17:55
Speaker 1: fuzziness to the universe and you just can't violate that.
17:58
Speaker 1: So having a singular already like a point of matter
18:01
Speaker 1: in its zero volume is you know, it would blow
18:04
Speaker 1: a quantum mechanics mind, right, but it's it's I guess
18:08
Speaker 1: technically quantum mechanics is about momentum, right, Momentum has a
18:12
Speaker 1: minimum size. Right, Well, it is about momentum, but it's
18:16
Speaker 1: about actually most measurable things like time, energy, space, and momentum.
18:21
Speaker 1: All these things come in finite grains like little quantum,
18:25
Speaker 1: a little basic units that you can't get smaller than.
18:28
Speaker 1: But even if, what if, like it's infinite mass, like
18:31
Speaker 1: a black hole, or like infinite density. Yeah, well, the
18:35
Speaker 1: quantum mechanics tells us that doesn't exist. You know that
18:37
Speaker 1: there's a there's a finite width to everything, and so
18:40
Speaker 1: you can't have infinitely small objects um. Quantum mechanics says,
18:45
Speaker 1: it just can't happen. But something is happening in there, right,
18:48
Speaker 1: there's something going on inside a black hole, and whatever
18:50
Speaker 1: it is, it's intense enough and dense enough to create
18:54
Speaker 1: a black hole. You don't need infinitely small points to
18:57
Speaker 1: create a black hole. You just need a density above
18:59
Speaker 1: a certain thresh hold. Genel relativity tells us it's an
19:02
Speaker 1: infinite singularity, but coonum mechanics says it can't be infinite. Right. Yeah,
19:06
Speaker 1: there's this idea that I thought was really cool that
19:08
Speaker 1: anything can become a black hole. Like if you squeeze
19:12
Speaker 1: it enough, it becomes a black hole. Right, Like if
19:15
Speaker 1: somebody squeezed me and my mass into a small enough volume,
19:19
Speaker 1: I would just like become a black hole, right. Yeah,
19:22
Speaker 1: it's a great idea, And I'm not sure like technically
19:25
Speaker 1: anything can become a black hole because you need to
19:28
Speaker 1: have a certain amount of mass per volume. But I
19:31
Speaker 1: guess in principle, if you compress something down far enough
19:34
Speaker 1: and it had some mass, then it would be dense
19:36
Speaker 1: enough to become a black hole. And black holes don't
19:39
Speaker 1: have to be huge. Black holes can also be tiny.
19:41
Speaker 1: For example, we're trying to create black holes at the
19:44
Speaker 1: large age on collider and those would be black holes
19:47
Speaker 1: like the size of protons. That is a great thought
19:49
Speaker 1: that I don't think a lot of people know is
19:50
Speaker 1: that black holes can be different sizes. Yeah. Absolutely, you
19:54
Speaker 1: can have a tiny one, or a huge one or
19:56
Speaker 1: an super massive gigantic one. That's right. And basically the
20:00
Speaker 1: only thing you can know about a black hole from
20:02
Speaker 1: the outside is um it's mass, which means its size,
20:05
Speaker 1: and it's rotation, so it's whether it's spinning or not.
20:09
Speaker 1: And so that's why we desperately want to know what's
20:12
Speaker 1: inside a black hole beyond our just our curiosity. Like
20:14
Speaker 1: anytime there's something in the universe you can't it's something
20:18
Speaker 1: in your house, for example, that you aren't allowed to
20:20
Speaker 1: look inside. Like if I said or I never look
20:22
Speaker 1: inside this box, you'd be definitely curious to see inside it. Right,
20:26
Speaker 1: So you're saying it's like the universe has has created
20:29
Speaker 1: a box and it it refuses to tell us what's inside.
20:32
Speaker 1: That's right, Well, this is a perfect point to take
20:36
Speaker 1: a break. If you could see inside it, um, you
20:49
Speaker 1: would learn something really deep about the way gravity works
20:52
Speaker 1: and quantum mechanics and how they're connected. It's like, you know,
20:56
Speaker 1: ten Nobel prizes worth of stuff hiding inside a black hole,
20:59
Speaker 1: maybe even an actual Nobel prize. So that's the answer
21:02
Speaker 1: to the question what's inside a black hole? Is uh,
21:06
Speaker 1: fame and fortune, a trip to Stockholm. So what would
21:11
Speaker 1: happen if you try to get near a black hole? Well,
21:14
Speaker 1: this is something you have to understand, which is something
21:16
Speaker 1: called a tidal force and um best way to understand
21:21
Speaker 1: it maybe is to think about what happens when things
21:23
Speaker 1: get near the sun for example. So one of my
21:25
Speaker 1: favorite examples came in when this comet came into our
21:29
Speaker 1: solar system and approach really close to the Sun. It's
21:32
Speaker 1: called comet Shoemaker Levy. That is that the one that
21:36
Speaker 1: almost missed Jupiter, That's the one that slammed right into Yeah. Yeah,
21:41
Speaker 1: it was pretty awesome to watch cosmic collisions. Um, but
21:45
Speaker 1: before it got there, it got torn apart by tidal forces.
21:48
Speaker 1: Oh shredded. Yeah, I got shredded. And um, say you're
21:53
Speaker 1: near a black hole, or you're near the Sun or something,
21:56
Speaker 1: then your head and your feet are not the same
21:58
Speaker 1: distance from the Sun. And because gravity depends on the distance,
22:02
Speaker 1: so like your head will be pulled in with greater
22:05
Speaker 1: force than your feet. If your head or closer than
22:08
Speaker 1: your feet, then yeah, there'll be a stronger force on
22:10
Speaker 1: your head than there is on your feet, right and
22:12
Speaker 1: effectively that means it's tearing you apart. But the difference
22:15
Speaker 1: would have to be greater than the forces holding me together. Exactly.
22:19
Speaker 1: Like right now you are sitting on the earth, and
22:21
Speaker 1: there is a greater force on the on your feet
22:23
Speaker 1: then there's on your head. So whatever part of your
22:25
Speaker 1: body is on the floor right now is feeling a
22:27
Speaker 1: stronger gravitational force than whatever part is elevated, right, Because
22:30
Speaker 1: it's further from the center of the Earth, gravity falls
22:33
Speaker 1: like one of the distance squared. So that's that's a
22:36
Speaker 1: pretty big factor. But the difference is not enough to
22:39
Speaker 1: overcome the forces that are holding me together. That's right,
22:42
Speaker 1: you're saying near a black hole, those differences are so
22:45
Speaker 1: huge he would actually shred your part. Yeah, exactly, like
22:48
Speaker 1: that comment that came into the Solar System got shredded
22:50
Speaker 1: by Jupiter and by the Sun. If you got too
22:52
Speaker 1: close to a black hole, you would get torn apart
22:54
Speaker 1: before you got anywhere near it. So it's in my
22:58
Speaker 1: view it's impossible to get very close to a black
23:00
Speaker 1: hole unless you're incredibly strong, like you need to build
23:04
Speaker 1: an object with really really tight bonds. Right. The things
23:07
Speaker 1: that are holding me together are the electromagnetic bonds between
23:10
Speaker 1: the atoms in my body, and gravity is constantly tugging
23:13
Speaker 1: on those if I'm near the Earth or near the Sun,
23:16
Speaker 1: tugging on those. But you know, not so hard and
23:18
Speaker 1: and where we've evolved to be strong enough to to
23:20
Speaker 1: not be shredded by the Earth, but not it's strong
23:23
Speaker 1: enough to be to not be shredded by a black hole. Right,
23:26
Speaker 1: So basically we may never be able to like go
23:28
Speaker 1: to a black hole and see what's inside, right, it's
23:30
Speaker 1: hard to imagine and and I hate to say never.
23:33
Speaker 1: I disamber because it prescribes future generations intelligence and there's
23:36
Speaker 1: probably some genius out there was a clever idea for
23:38
Speaker 1: how to do it. It's not theoretically impossible to be
23:41
Speaker 1: near a black hole. It's just practically very difficult, which
23:44
Speaker 1: makes it, you know, a pretty tough engineering problem. So
23:50
Speaker 1: we know black holes are out there, we know they're mysterious,
23:53
Speaker 1: we know they contain some deep, dark secret. We don't
23:56
Speaker 1: think they contain the anti universe. I don't believe they
23:58
Speaker 1: contain worm whole. I don't know, you know, they don't
24:02
Speaker 1: believe they contain worms or anything else weird. But I
24:06
Speaker 1: would love to get to know what's inside a black hole.
24:08
Speaker 1: I don't know about visiting one, or seeing one, or
24:10
Speaker 1: getting too close to one and getting shredded, and desperately
24:13
Speaker 1: want to know what's inside a black hole. Maybe side
24:15
Speaker 1: will find my marbles lost for sure. All right, thanks
24:20
Speaker 1: everyone for listening to Daniel and Jorge explain the universe.
24:24
Speaker 1: Thanks for listening. Do you have a question you wish
24:31
Speaker 1: we would cover send it to us. We'd love to
24:34
Speaker 1: hear from you. You can find us on Facebook, Twitter,
24:36
Speaker 1: and Instagram at Daniel and Jorge One Word, or email
24:40
Speaker 1: us to feedback at Daniel and Jorge dot com