Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions: photon information, simulated Universes and Daniel's fantasy science budget

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Listener Questions: photon information, simulated Universes and Daniel's fantasy science budget · Daniel and Kelly’s Extraordinary Universe

0:09
Speaker 1: When you were a kid, did you ever dream about
0:11
Speaker 1: being the president? Maybe you were attracted to the personal jet,
0:15
Speaker 1: or did the bulletproof car, or the free housing or
0:17
Speaker 1: the sheer fame and power of the position. I was
0:21
Speaker 1: recently surprised to learn that most of today's kids don't
0:24
Speaker 1: want to be president. Only one quarter of ten to
0:28
Speaker 1: sixteen year old recently surveyed said they had presidential aspirations.
0:32
Speaker 1: And when they asked kids what they did want to
0:34
Speaker 1: be when they grew up, president came in last. It
0:37
Speaker 1: was tied with alien. Now. I have no personal interest
0:41
Speaker 1: in being president. It sounds like a stressful, thankless job.
0:44
Speaker 1: I'd rather win a Nobel prize in a presidential election.
0:47
Speaker 1: But it makes me wonder what it would be like
0:49
Speaker 1: if we had a scientist president. Would they be tempted
0:53
Speaker 1: to fund a lot more science? Like a lot more science?
0:56
Speaker 1: And you might be wondering how many black hole creating
1:00
Speaker 1: particle accelerators does one planet need? Anyway, my answer is
1:04
Speaker 1: less elected scientists and find out. Hi. I'm Daniel, I'm
1:23
Speaker 1: a particle physicist, and I'm a big booster of spending
1:26
Speaker 1: money on science, not just because I'm a scientist and
1:30
Speaker 1: I benefit directly from all that funding, but because there
1:33
Speaker 1: are so many things out there in the universe we
1:36
Speaker 1: could learn if we just spent the cash. We are
1:39
Speaker 1: living literally in a store of science knowledge, and we
1:43
Speaker 1: are being very, very stingy with our spending. So many
1:46
Speaker 1: deep secrets of the universe we could unravel if we
1:49
Speaker 1: only loosened our wallet and spent a little bit more
1:52
Speaker 1: money on science, and we wouldn't even need to spend
1:55
Speaker 1: less money on other things. But welcome to the podcast
1:58
Speaker 1: Daniel and Jorge explain the universe, in which we take
2:02
Speaker 1: you on a mental journey through all of the things
2:04
Speaker 1: that we do know and all of the things that
2:06
Speaker 1: science is still trying to figure out. We are not shy.
2:10
Speaker 1: We tackled the biggest questions in the universe. Why is
2:13
Speaker 1: it here? What's going to happen to it? How does
2:15
Speaker 1: it all work? From the tiniest little particles vibrating in
2:18
Speaker 1: your fingertips to the massive, incredible climactic collisions of galaxies.
2:24
Speaker 1: We talk about all of it, and most importantly, we
2:26
Speaker 1: make banana jokes and try to make all of it
2:28
Speaker 1: accessible to you. Usually on the podcast, I'm here joking
2:31
Speaker 1: around and explaining science with my friend and colleague jorgey Champ,
2:35
Speaker 1: creator of pH D Comics. He couldn't be with us
2:37
Speaker 1: here today, so I'm taking the opportunity to catch up
2:40
Speaker 1: on questions from our listeners. We are always asking questions
2:45
Speaker 1: on this podcast and sometimes answering one war two of them.
2:48
Speaker 1: But we also encourage our listeners to ask questions because
2:51
Speaker 1: science is not something done just by people wearing white
2:54
Speaker 1: lab coats and eye protections in silly looking labs in movies.
2:58
Speaker 1: It's something we all do. The process of science is
3:02
Speaker 1: simply just some mental instrument for accumulating knowledge, for diving
3:06
Speaker 1: into these puzzles that everyone wants the solutions to. What
3:09
Speaker 1: does it mean to be a human in this universe
3:12
Speaker 1: depends on which universe we are in and how it works.
3:16
Speaker 1: And as through history we have learned more and more
3:18
Speaker 1: about the universe, it's changed what it meant to be human. Frankly,
3:22
Speaker 1: it's made us feel less and less important and less
3:25
Speaker 1: and less central. But at least we know the truth.
3:27
Speaker 1: At least we know where we stand and where we
3:30
Speaker 1: don't stand in the universe. So, if you're the kind
3:32
Speaker 1: of person who wants to know answers to deep questions
3:35
Speaker 1: about the universe. You are definitely in the right place,
3:38
Speaker 1: and you are welcome to send us your questions if
3:41
Speaker 1: we haven't tackled it on one of our almost three
3:43
Speaker 1: hundred episodes of this podcast, You're welcome to send us
3:46
Speaker 1: a question to questions at Daniel and Jorge dot com.
3:50
Speaker 1: Most of them I will answer almost right away. You
3:53
Speaker 1: are guaranteed a response, and some of them I will
3:56
Speaker 1: put right here on the podcast and discuss in more
3:58
Speaker 1: depth because I think that other people might also want
4:02
Speaker 1: to know the answer to these questions, or I just
4:04
Speaker 1: think they're super fun and I want to talk about them.
4:06
Speaker 1: So today on the podcast, we have more listener questions.
4:16
Speaker 1: Today we have super fun questions about photons, we have
4:19
Speaker 1: questions about simulated universes, and we have questions about what
4:24
Speaker 1: to spend science money on. So, without further ado, let's
4:29
Speaker 1: dive right in and get to our first question. This
4:32
Speaker 1: is a question from Brad from Montana. Brad is actually
4:36
Speaker 1: an artist who carves wooden spoons and other things. I
4:39
Speaker 1: checked out his website. It looks pretty cool. You all
4:41
Speaker 1: should check it out. Anyway. Here is Brad's question. It's
4:45
Speaker 1: more so like a series of questions and just expression
4:48
Speaker 1: of not knowing what's going on here um And it
4:52
Speaker 1: is just one specific question, but it seems like every
4:55
Speaker 1: almost every bit of knowledge we have about the cosmos
4:58
Speaker 1: in the universe, we have learned through interpreting light and
5:04
Speaker 1: the information that's in light, which as far as I know,
5:07
Speaker 1: is just photons. And what I don't know is how
5:11
Speaker 1: exactly on the I want to say microscopic, but that's
5:15
Speaker 1: not even it on the atomic level or the sub
5:17
Speaker 1: atomic level, how is that light actually made? And how
5:22
Speaker 1: does the information get in there um to the photon?
5:25
Speaker 1: Is it the frequency of which something is vibrating when
5:32
Speaker 1: it emits the light, or is it some other property
5:35
Speaker 1: inherent to the photon that has traveled millions and millions
5:39
Speaker 1: of light years to get to us. It seems like
5:42
Speaker 1: a photon is this witless, massless thing going at the
5:47
Speaker 1: speed of light, but it can have so much different
5:51
Speaker 1: information in it. There must be something that it's doing
5:54
Speaker 1: that would make one piece of light different than another
5:58
Speaker 1: piece of light. Like what is the phoe ton actually
6:00
Speaker 1: doing differently that makes it have different information in it?
6:05
Speaker 1: And uh so I'd love to know that. And then
6:07
Speaker 1: on the very sub atomic level, how do those photons
6:11
Speaker 1: get kicked out from whatever they're getting kicked out on UM.
6:15
Speaker 1: I would just love any information on that. I hope
6:18
Speaker 1: to hear it on the pod someday. Thanks. I love
6:21
Speaker 1: the pod, listen to every episode. Thanks guys. All Right,
6:24
Speaker 1: that was an awesome question from Brad. I love how
6:27
Speaker 1: he's thinking about the way we learned what we learned,
6:31
Speaker 1: because it's really amazing, when you think about it for
6:33
Speaker 1: a moment, how much we do know about the universe,
6:36
Speaker 1: never having left this tiny little rock. We know so
6:40
Speaker 1: much about the Solar System, about the structure of the galaxy,
6:43
Speaker 1: about nearby galaxies, about the whole galaxy cluster, about superclusters
6:47
Speaker 1: of galaxies, and the incredible sheets and filaments that they
6:51
Speaker 1: form at the very very largest scale of the universe.
6:54
Speaker 1: And of course, no human has ever even left the
6:57
Speaker 1: vicinity of Earth. So it's incredible that we've learned so much.
7:00
Speaker 1: And you're totally right, Brad, that almost all of that
7:03
Speaker 1: information comes to us in the form of light. Just
7:06
Speaker 1: by opening our scientific eyeballs and receiving that light, we
7:10
Speaker 1: are getting so much information about the structure of the universe.
7:14
Speaker 1: So the way I take your question is, how is
7:16
Speaker 1: that information encoded. First of all, what makes that light,
7:20
Speaker 1: how is it made, how does it pass to us
7:23
Speaker 1: through the universe? And then how do we figure out
7:25
Speaker 1: what it means? How is a photon actually storing information?
7:29
Speaker 1: So I think the first thing to do is to
7:30
Speaker 1: understand what we mean by a photon. And remember that
7:34
Speaker 1: photons are all just wiggles in the electromagnetic field. They're
7:38
Speaker 1: all just different kinds of electromagnetic radiation. And you're very
7:41
Speaker 1: familiar with electromagnetic radiation. Light, for example, from your light bulb,
7:46
Speaker 1: is e M radiation and it's different from for example,
7:49
Speaker 1: X rays that the doctors used to see your insides,
7:52
Speaker 1: but they are both electromagnetic radiation. The difference between visible
7:56
Speaker 1: light and X rays and gamma rays and infrared and
8:00
Speaker 1: radio is just the frequency at which those photons are wiggling.
8:04
Speaker 1: So they all travel at the same speed. The speed
8:07
Speaker 1: of light is the speed of light, it's always the same.
8:10
Speaker 1: But the photons wiggle at different frequencies, which means conversely
8:13
Speaker 1: they have different wavelengths. So at the very long wavelength
8:17
Speaker 1: like infrared and radio, these things don't wiggle as often,
8:21
Speaker 1: so the wavelength is longer even though they're moving at
8:23
Speaker 1: the same speed, and then at the very very high frequency,
8:27
Speaker 1: the short wavelength, we have things like ultra violets and
8:30
Speaker 1: X rays and gamma rays. We divide these things up
8:32
Speaker 1: and give them different names, mostly because historically we discovered
8:36
Speaker 1: them in different ways and experience them in different ways,
8:38
Speaker 1: Like X rays were discovered by Runkin and we have
8:41
Speaker 1: a whole fun podcast about exactly how that happened. And
8:44
Speaker 1: qualitatively they are different from visible light because we didn't
8:48
Speaker 1: know they existed for a while, and they can do
8:49
Speaker 1: things visible light can't. But conceptually they're really just all
8:53
Speaker 1: different kinds of photons. So when we look out at
8:56
Speaker 1: the night sky we receive photons from space. What information
8:59
Speaker 1: is encoded in those photons, Well, a photon is a
9:03
Speaker 1: photon is a photon. The only difference really is the frequency.
9:07
Speaker 1: So you get a photon from space, you can measure
9:09
Speaker 1: its frequency. You can say, oh, that was a red photon,
9:12
Speaker 1: or that was an infrared photon, or that was a
9:14
Speaker 1: radio photon or a gamma ray photon for example. You
9:18
Speaker 1: can measure the frequency of a photon by measuring its energy, right,
9:23
Speaker 1: because the speed of the photon doesn't depend on the frequency,
9:27
Speaker 1: it's all the same, but the energy of the photon
9:30
Speaker 1: is linked to its frequency. There's this expression energy is
9:33
Speaker 1: planks constant times the frequency, and so by measuring the
9:37
Speaker 1: energy of the photon, you can tell what its frequency is,
9:40
Speaker 1: and that's basically the information that a photon carries. You
9:43
Speaker 1: know what direction it came from and what frequency it has,
9:47
Speaker 1: and that's all the information. Now, technically there's another layer
9:50
Speaker 1: of information there because photons are bosons and they have spin,
9:54
Speaker 1: and you can tell how they're spinning. Also, that's not
9:56
Speaker 1: the level of information that we typically know how to
9:58
Speaker 1: take advantage of in a strong me so there are
10:01
Speaker 1: some applications of measuring the spin and the polarization of
10:04
Speaker 1: those photons which can take advantage of it. So you ask,
10:07
Speaker 1: like how a photon can store so much information. The
10:11
Speaker 1: photon itself can't store that much, and you know, it
10:14
Speaker 1: is a massless particle. It is this tiny little wisp
10:17
Speaker 1: of energy. But the fact that that energy was made
10:20
Speaker 1: and it's coming to us from a certain direction, that's
10:23
Speaker 1: also a lot of information. Right. The context tells you
10:27
Speaker 1: something about it. Like if you look up in the
10:29
Speaker 1: night sky and you see a bunch of photons of
10:31
Speaker 1: the same frequency, all hitting your eyeball. What do you know, Well,
10:35
Speaker 1: you know there are a bunch of photons coming from
10:37
Speaker 1: the same direction. But also you can infer that there's
10:40
Speaker 1: something there. There's something out there generating those photons at
10:44
Speaker 1: a specific frequency, and that gives you a clue. It
10:47
Speaker 1: helps you sort of unravel and astrophysical mystery and say, well,
10:51
Speaker 1: what do I know that's capable of generating those photons?
10:55
Speaker 1: So that goes to the other part of your question,
10:57
Speaker 1: which is what can make these photons? How are they
11:00
Speaker 1: actually made? And how does that tell us about what's
11:02
Speaker 1: doing the photon making. Let's remember again what a photon is,
11:06
Speaker 1: if a ripple in electromagnetic fields, how do you make
11:10
Speaker 1: ripples in electromagnetic fields? Well, one way you can do
11:13
Speaker 1: it is you take a charge particle like an electron.
11:16
Speaker 1: Electron just sitting by itself has an electric field. Right,
11:19
Speaker 1: For example, it will repel another electron, it will attract
11:23
Speaker 1: a positively charged particle. So just put an electron in
11:26
Speaker 1: space and it has an electric field. Now take that
11:28
Speaker 1: electron and move it right, wiggle it. What happens to
11:32
Speaker 1: the electric field? Well, electric fields don't instantly move. If
11:36
Speaker 1: you slide that electron one to the left. The electric
11:39
Speaker 1: field like a mile away or a kilometer way, doesn't
11:42
Speaker 1: instantly change. It takes a moment for that information to
11:46
Speaker 1: propagate through the electric field. And if you slide the
11:49
Speaker 1: electron to the left and then back again, and to
11:51
Speaker 1: the left and to back again, what do you get.
11:54
Speaker 1: You get ripples in the electric field right, because you're
11:57
Speaker 1: moving the electron. And it's just like if you put
12:00
Speaker 1: ripples in water, right, tap your hand into a bathtub
12:03
Speaker 1: and make ripples in the water. Those ripples have a frequency.
12:06
Speaker 1: It's the frequency at which you are tapping the water.
12:09
Speaker 1: The same way you take your electron and you wiggle
12:12
Speaker 1: it in space at a certain frequency. What are you doing.
12:15
Speaker 1: You're generating electromagnetic radiation. Those ripples in the electric field
12:20
Speaker 1: are electromagnetic radiation at a specific frequency. So you are
12:24
Speaker 1: creating photons by dialing up the frequency that you're wiggling
12:28
Speaker 1: the electron. And this is how anintenna works. An antenna
12:32
Speaker 1: is just a long column with a bunch of electrons
12:34
Speaker 1: in it that we can control their wiggling. We can say,
12:37
Speaker 1: all right, wiggle at this frequency, now stop. Now wiggle
12:39
Speaker 1: at that frequency, now stop. And when they do that, wiggling,
12:43
Speaker 1: they generate photons at the frequency that they are wiggling.
12:47
Speaker 1: So if your electrons are moving at four point two
12:49
Speaker 1: mega hurts, for example, then you will be generating photons
12:52
Speaker 1: at that frequency. And that's also how anintenna works to
12:55
Speaker 1: receive messages. Right, The photons come in which are just
12:59
Speaker 1: wiggles in the electric field, and they wiggle the electrons
13:03
Speaker 1: in the antenna at their frequency, and we can measure
13:06
Speaker 1: the wiggling of electrons in a metal antenna, right, That
13:09
Speaker 1: creates a current and oscillating current which we can measure.
13:12
Speaker 1: So that's how we receive and send photons because they
13:16
Speaker 1: really just are ripples in the electromagnetic field. So that's
13:19
Speaker 1: how you could make a photon of any arbitrary frequency
13:22
Speaker 1: that you want. But there aren't like antennas out there
13:25
Speaker 1: in space sending us these messages, at least we haven't
13:28
Speaker 1: received any yet. Instead, what we have are natural objects
13:31
Speaker 1: like stars, or like clouds of gas, or quasars or
13:35
Speaker 1: black holes or creation disks. These things are sending us radiation.
13:40
Speaker 1: How does that happen if there are not antennas out there,
13:43
Speaker 1: how are they sending us photons? Well, the picture I
13:45
Speaker 1: told you a moment ago of a single electron in
13:48
Speaker 1: space is simplified. These electrons do exist, but they exist
13:51
Speaker 1: inside matter. An electron that's for example, captured by a
13:55
Speaker 1: nucleus can't just wiggle in any arbitrary frequency. It has
13:59
Speaker 1: energy levels to quantum mechanics, and so what it can
14:02
Speaker 1: do is it can orbit the atom at a certain
14:04
Speaker 1: energy level, and they can orbit the atom at another
14:07
Speaker 1: energy level, and when it moves between one of those two,
14:10
Speaker 1: it can emit a photon. So, for example, if you
14:12
Speaker 1: have a gas which is really really hot, meaning has
14:15
Speaker 1: a lot of energy in it, then the electrons inside
14:17
Speaker 1: it are excited there at some high energy level. When
14:21
Speaker 1: they jump down to a lower energy level, they give
14:24
Speaker 1: up some of their energy. How do they do that.
14:26
Speaker 1: They do that by emitting a photon. A photon carries
14:29
Speaker 1: away some of that energy, and the frequency of that photon,
14:33
Speaker 1: again is connected to the energy of the photon. There's
14:36
Speaker 1: a relationship there. The energy is planks constant times the frequency.
14:41
Speaker 1: So if there's a specific energy gap for an atom,
14:44
Speaker 1: it can only generate photons of that frequency, and that's
14:48
Speaker 1: how we can tell what's out there. So you get,
14:50
Speaker 1: for example, a bunch of photons at a specific frequency,
14:53
Speaker 1: you can say, oh, that's hydrogen over there in that
14:56
Speaker 1: cloud that's getting really hot and then cooling down and
14:59
Speaker 1: sending us photons. So just from the frequency of light,
15:02
Speaker 1: you can tell what it is that's emitting. And this
15:05
Speaker 1: is super important and super powerful information, and it's true
15:09
Speaker 1: about almost every kind of material. If you take hydrogen,
15:12
Speaker 1: for example, it tends to emit at several different frequencies.
15:15
Speaker 1: Those frequencies correspond to an electron jumping down one energy
15:19
Speaker 1: level or two energy levels, or three energy levels, or
15:22
Speaker 1: from energy level three to two for example. There's a
15:24
Speaker 1: spectrum there, a series of lines that are like a
15:27
Speaker 1: fingerprint that tell you this is hydrogen. So a hydrogen
15:31
Speaker 1: cloud doesn't just emit at one frequency, emits at a
15:34
Speaker 1: set of frequencies which are unique to hydrogen because helium
15:37
Speaker 1: and other elements have different energy levels and they emit
15:41
Speaker 1: at different frequencies, and so you can get a whole
15:44
Speaker 1: bunch of light from a cloud. You can tell, oh,
15:46
Speaker 1: look it's mostly hydrogen, but there's some helium and a
15:48
Speaker 1: little bit of lithium and all this kind of stuff.
15:50
Speaker 1: And that's how we can tell the molecular composition of
15:53
Speaker 1: what's out there just by looking at the frequencies. So
15:56
Speaker 1: these frequencies contain so much rich information if you also
16:00
Speaker 1: have the context of understanding how to make light at
16:03
Speaker 1: those various frequencies, it also super interestingly works the other direction.
16:08
Speaker 1: Maybe you have a source of light, like a star
16:10
Speaker 1: that tends to emit it almost every frequency, and you
16:12
Speaker 1: put a cloud of gas in front of it. What happens, Well,
16:16
Speaker 1: that cloud of gas will absorb some photons, but which ones,
16:20
Speaker 1: only the ones that correspond to the energy levels of
16:23
Speaker 1: the electrons inside of it. So, for example, a cloud
16:26
Speaker 1: of hydrogen will tend to absorb photons at only those
16:30
Speaker 1: frequencies that match its energy levels. So what do you
16:33
Speaker 1: get from the other side is you get a broad
16:36
Speaker 1: spectrum of light almost every frequency with some gaps in it.
16:39
Speaker 1: And those gaps are exactly at the same frequencies you
16:42
Speaker 1: would get if you took the hydrogen, heat it up
16:44
Speaker 1: and let it emit, So those things match perfectly. It's
16:47
Speaker 1: a really nice little sort of key and lock kind
16:50
Speaker 1: of situation. But there's even more to it than that,
16:53
Speaker 1: because these different frequencies let you see the universe in
16:56
Speaker 1: different ways, just the same way that like visible light
17:00
Speaker 1: gives you one picture of the universe, but X rays
17:03
Speaker 1: give you a different picture of the same things around you.
17:06
Speaker 1: Right if you look at your arm invisible light, you
17:09
Speaker 1: see the skin. Why is that because mostly your body
17:12
Speaker 1: is opaque to visible light. The visible light is absorbed
17:16
Speaker 1: by your body or reflected by it. It's not transparent
17:20
Speaker 1: to visible light. But X rays can pass through your
17:24
Speaker 1: body without being absorbed because they're not of the frequency
17:27
Speaker 1: that your body can absorb, so they can pass right
17:30
Speaker 1: through you, except, of course, some things inside you which
17:33
Speaker 1: do tend to absorb X rays, and so X rays
17:36
Speaker 1: will let you see through your body in a way
17:38
Speaker 1: the visible light can't. We can do exactly the same
17:41
Speaker 1: thing with different frequencies of light and apply it to
17:44
Speaker 1: the whole universe, because there are lots of different things
17:47
Speaker 1: out there in the universe, and some of them are
17:48
Speaker 1: transparent to visible light, and some of them are opaque
17:52
Speaker 1: to visible light, like huge clouds of gas and dust
17:56
Speaker 1: mostly absorbed visible light. And so if you want to see,
17:59
Speaker 1: for example, in the center of the galaxy, where things
18:02
Speaker 1: are very crowded and there's lots of gas and dust,
18:05
Speaker 1: it's choking things up and it's hard to see what's
18:07
Speaker 1: going on. In the optical spectrum, you can use other
18:10
Speaker 1: frequencies of light. You can look for photons and other
18:13
Speaker 1: frequencies which are not as easily absorbed by gas and dust,
18:18
Speaker 1: and specifically longer frequency photons. Photons in the radio spectrum
18:23
Speaker 1: or in the infrared are not as easily absorbed by
18:26
Speaker 1: gas and dust, and so it's easier to see through
18:29
Speaker 1: those clouds. So if you like put on a different filter,
18:32
Speaker 1: you can see through stuff that was blocking your view.
18:35
Speaker 1: So I think that's super cool because it lets you
18:37
Speaker 1: see different things in the universe. Also, things tend to
18:41
Speaker 1: radiate light depending on their temperature, so the hotter something is,
18:46
Speaker 1: the higher the frequency light that comes from it. That's
18:48
Speaker 1: why the Sun, for example, emits in the visible light.
18:51
Speaker 1: The Earth also glows, it just doesn't glow in the
18:54
Speaker 1: visible light. It glows in infrared because the Earth is
18:57
Speaker 1: cooler than the Sun and so it emits it at
19:00
Speaker 1: lower frequencies. So it's sort of like a star glowing
19:03
Speaker 1: in a frequency that we can't even see. But if
19:05
Speaker 1: you turn on a telescope like the James web Space
19:08
Speaker 1: telescope that can look in the infrared, then you can
19:11
Speaker 1: see these things which are otherwise invisible to the naked eye,
19:14
Speaker 1: like planets, don't glow in the visible so if you
19:17
Speaker 1: use houbble you can't see them. But if you use
19:19
Speaker 1: the James web Space telescope, you can pick up photons
19:23
Speaker 1: in the infrared spectrum and you can see colder things,
19:27
Speaker 1: huge clouds of gas and dust, and also maybe even planets.
19:31
Speaker 1: One last comment I want to make is that you
19:33
Speaker 1: are right that almost everything we've learned about the universe
19:36
Speaker 1: we have done so using light. Using electromagnetic radiation is
19:40
Speaker 1: very powerful, but it's not the exclusive method by which
19:44
Speaker 1: we get information about the universe, right. We also can
19:48
Speaker 1: get information using gravitational waves. These are these weird ripples
19:52
Speaker 1: in space and time created when, for example, black holes
19:56
Speaker 1: orbit each other and fall in and merge. And that's
19:58
Speaker 1: very different kind of radiation. It's not a ripple in
20:01
Speaker 1: the electromechnetic spectrum. It's a ripple in the fabric of
20:04
Speaker 1: space itself. So it's similar in that it is a
20:08
Speaker 1: wiggle in something and it's a radiation, but it's not
20:11
Speaker 1: radiation of photons. We don't know if gravitational waves are
20:15
Speaker 1: made of quanties gravitons yet, but we have seen gravitational waves.
20:19
Speaker 1: They are real and they are not photons. Also, we
20:22
Speaker 1: can look for particles from space which are like ripples
20:25
Speaker 1: in matter fields. For example, neutrinos are a very powerful
20:30
Speaker 1: way to probe what's going on in the universe. They
20:32
Speaker 1: are these incredible messengers because they can pass through almost everything,
20:36
Speaker 1: and so we can use other kinds of particles to
20:39
Speaker 1: understand what else is going out there in the universe.
20:41
Speaker 1: And these days we call that multi messenger astronomy. It's
20:44
Speaker 1: a very cool way to see the universe with different
20:47
Speaker 1: kinds of glasses on. The more eyeballs you turn onto
20:50
Speaker 1: the universe, the more you learn about it. All right,
20:53
Speaker 1: so thank you Brad for that super fun question, for
20:55
Speaker 1: letting me talk about the exciting things we can learn
20:58
Speaker 1: about the universe using photon. I want to answer a
21:00
Speaker 1: couple more questions, but first let's take a quick break.
21:16
Speaker 1: All right, we're back in. It's Daniel answering listener questions
21:20
Speaker 1: from our wonderful, good looking, intelligent, clever, friendly listeners who
21:25
Speaker 1: send in their deep thoughts about the universe. I love
21:28
Speaker 1: hearing from all of you, guys. Please please please write
21:31
Speaker 1: to us. I know that you are out there. You
21:33
Speaker 1: have questions about the universe and you have not written
21:36
Speaker 1: to us, and I don't know why. So please send
21:39
Speaker 1: us your questions to questions at Daniel and Jorge dot com.
21:42
Speaker 1: I promise you you'll get a personal reply. Our next
21:46
Speaker 1: question comes from a pair of curious folks from Brazil.
21:50
Speaker 1: Hey guys, this is Rodrigo and Brazilian believe in the
21:53
Speaker 1: UK at the moment. I love the show and so
21:55
Speaker 1: does my two year old son. Page right, page right.
21:58
Speaker 1: I love the podcast too and have a question about
22:00
Speaker 1: the simulation. I thought this is exactly so. Our question
22:04
Speaker 1: today is whether the quantized nature of our universe and
22:07
Speaker 1: the fact that we observe a speed limit of sorts,
22:09
Speaker 1: which is a speed of light, might add to the
22:11
Speaker 1: probability of us actually being a simulation, since we could
22:15
Speaker 1: argue that bits or quanta and processing speed limits are
22:19
Speaker 1: aspects would expect to observe in any computational system and
22:22
Speaker 1: that might not necessarily be present in the real ultimate universe.
22:26
Speaker 1: That's it. We would love to hear thoughts about that.
22:28
Speaker 1: Thank you so much and keep up the great work.
22:30
Speaker 1: All right, Well, this question super fun, kind of silly,
22:34
Speaker 1: but also very very serious. It goes to the heart
22:38
Speaker 1: of the nature of our reality. Are we living in
22:41
Speaker 1: a simulation? Are we living in a real universe? Could
22:44
Speaker 1: we tell the difference? So thank you very much Rodrigo
22:47
Speaker 1: and Pedro for sharing your curiosity and the super fun question.
22:51
Speaker 1: And thanks to Rodrigo for sharing his love of science
22:54
Speaker 1: and deep thinking with the next generation. So let's first
22:57
Speaker 1: revisit the super fun question of are we living in
23:01
Speaker 1: a simulation? If you haven't heard this before, this is
23:04
Speaker 1: the idea that maybe everything around us isn't real in
23:09
Speaker 1: some deep sense, but instead maybe we are all inside
23:13
Speaker 1: a computer run by some other kind of creature in
23:17
Speaker 1: some other kind of universe. And the genesis of the
23:20
Speaker 1: idea comes from the our ability to simulate universes. We
23:24
Speaker 1: have powerful computers now, and on those computers we can
23:28
Speaker 1: run simulations. We can say what happens if you take
23:31
Speaker 1: a star and you shoot it against another star? Or
23:34
Speaker 1: what happens if you have ten to the six stars?
23:37
Speaker 1: Do they form a galaxy? This is a very important
23:40
Speaker 1: part of doing science. Are these simulated experiments? Because sometimes
23:44
Speaker 1: things are just too complicated to write everything down with
23:46
Speaker 1: pencil and paper, and so we need to like code
23:49
Speaker 1: in the rules of the universe and then simulate it
23:52
Speaker 1: just to see what happens. This is often the case
23:55
Speaker 1: when we have a complex emergent phenomena when it's difficult
23:59
Speaker 1: to dick from the underlying rules, but we can use
24:02
Speaker 1: a simulation to figure out what happens. And the way
24:04
Speaker 1: the simulation works is you write the rules down, you
24:08
Speaker 1: specify the initial conditions, like you say, there's a star
24:11
Speaker 1: over here, there's a star over there, and there's a
24:13
Speaker 1: star over here, and then you say go and the
24:15
Speaker 1: simulation takes over and it says, well, I know where
24:18
Speaker 1: everything is right now, and I know where the rules
24:21
Speaker 1: are for how to update my universe. And it makes
24:24
Speaker 1: a little change in the universe. It says, all right,
24:26
Speaker 1: let's take a one time step forward by half a
24:28
Speaker 1: second or by two seconds or whatever, and I'll move
24:32
Speaker 1: all the stars a little bit, and then I'll do
24:34
Speaker 1: it again. And in that way you can describe really
24:37
Speaker 1: complicated things like hurricanes or galaxy formations, even if you
24:40
Speaker 1: can't ever sit down and write like the math directly
24:43
Speaker 1: for a hurricane or how a galaxy forms. So it's
24:46
Speaker 1: a very powerful tool. But people notice that they're writing
24:49
Speaker 1: down basically the laws of physics into a computer and
24:53
Speaker 1: they're creating inside their computer a simulated universe. And the
24:57
Speaker 1: idea is, what if you could write a seem reulation
25:00
Speaker 1: that was so complicated, so sophisticated that it could simulate
25:04
Speaker 1: the workings of a human brain. Would that human brain
25:07
Speaker 1: think that it was alive? Would it think that it existed?
25:10
Speaker 1: Would it have a subjective, first personal experience? That of
25:13
Speaker 1: course goes to the heart of the question of what
25:16
Speaker 1: is consciousness and is it just information or does it
25:19
Speaker 1: rely on the actual configuration of our neurons. But imagine
25:23
Speaker 1: for a moment we put that impossible to answer difficult
25:26
Speaker 1: question aside, and we assume that a perfect simulation of
25:29
Speaker 1: your mind would have exactly the same experience as you.
25:33
Speaker 1: It would think that it was alive. In that scenario,
25:36
Speaker 1: then you could imagine writing a simulation which was so
25:39
Speaker 1: good that something in it would not know it was
25:43
Speaker 1: in a simulation. It would experience the universe that you
25:47
Speaker 1: have created inside your computer, and it would think it
25:50
Speaker 1: was real. Now, if you believe that, then it only
25:53
Speaker 1: takes one more step to reflect it back on yourself
25:56
Speaker 1: and say, hold on a second, how do I know
25:58
Speaker 1: that the universe I'm living in isn't a simulation? Is
26:02
Speaker 1: it possible that I'm nothing more than information in some giant,
26:07
Speaker 1: incredibly complicated computer capable of simulating an entire universe. That's
26:13
Speaker 1: a pretty big idea to hold in your head, and
26:15
Speaker 1: maybe it makes you a little queasy to wonder, like,
26:17
Speaker 1: who's out there, who's programming the universe? But it also
26:21
Speaker 1: kind of makes sense in some way because there is
26:25
Speaker 1: a similarity to the structure of a computer program and
26:29
Speaker 1: the structure of a universe. Right, a universe seems to
26:33
Speaker 1: follow rules like for reasons we don't really understand, the
26:37
Speaker 1: universe is describable using mathematical physical laws, and those physical
26:43
Speaker 1: laws don't seem to change. You do an experiment today,
26:46
Speaker 1: and you do the same experiment in a month or
26:48
Speaker 1: in a hundred years, you should get the same answer
26:50
Speaker 1: because you're probing some true physical law that governs what
26:54
Speaker 1: happens in our universe. That's also the same principle behind
26:59
Speaker 1: a simularation, Right, You write down the laws of what happens,
27:02
Speaker 1: and then it's just sort of churns forward implementing them mindlessly.
27:06
Speaker 1: So that's kind of cool, and it sort of feels
27:08
Speaker 1: like by revealing the physical laws of the universe how
27:12
Speaker 1: our universe runs. You might ask, are we revealing physical
27:15
Speaker 1: laws or are we revealing the source code of the universe?
27:20
Speaker 1: Are we revealing the way the universe is calculated? Something
27:24
Speaker 1: I've often wondered is you know where are these calculations done?
27:28
Speaker 1: Like if I do an experiment in my laboratory and
27:31
Speaker 1: I shoot one particle at another particle, I can calculate
27:35
Speaker 1: what's going to happen. But how does the universe decide
27:39
Speaker 1: what's going to happen? Is there a calculation being done somewhere?
27:43
Speaker 1: Is the universe basically like a computer that is doing
27:47
Speaker 1: these calculations. You could even imagine, for example, using the
27:50
Speaker 1: universe's physical laws to effectively do calculations that we don't
27:55
Speaker 1: have complex enough computers to do. Anyway, back to the
27:58
Speaker 1: question from Rodrigoing, he drew, they notice a couple of
28:01
Speaker 1: things about our universe, namely the fact that we have
28:04
Speaker 1: a speed limit at the speed of light and the
28:07
Speaker 1: fact that the universe seems to be quantized, that it's
28:11
Speaker 1: like broken up into chunks, And they wonder, are these
28:14
Speaker 1: clues that we are living in a simulation. So first,
28:18
Speaker 1: let's argue for yes, and then I'll tell you why
28:20
Speaker 1: I think the answer is probably no. The argument for yes,
28:24
Speaker 1: why these might be clues that we would be living
28:26
Speaker 1: in a simulation is that they are the kinds of
28:28
Speaker 1: things we might encode into a simulation. We wrote. For example,
28:32
Speaker 1: if you limit the speed that information can move through
28:36
Speaker 1: your universe, it makes it a lot easier to program
28:39
Speaker 1: your universe because you can separate it into pieces. If
28:42
Speaker 1: you know that nothing that happens and this left corner
28:45
Speaker 1: of the universe can possibly influence the top right corner
28:47
Speaker 1: of the universe within a certain amount of time, then
28:50
Speaker 1: you don't have to do those calculations. Often when we
28:52
Speaker 1: do really big complex simulations, that's the kind of thing
28:55
Speaker 1: we're doing, is we're looking for shortcuts calculations we don't
28:58
Speaker 1: really need to do. For example, in principle, you are
29:03
Speaker 1: affected by the electric fields from electrons in the Andromeda
29:07
Speaker 1: galaxy because the extent of the electromagnetic field is infinite,
29:12
Speaker 1: But in practice that makes no difference to you or
29:14
Speaker 1: what happens to you or changes your life at all.
29:17
Speaker 1: So if you were doing the calculation, you could just
29:19
Speaker 1: set that to zero rather than actually calculating it and
29:22
Speaker 1: get the same answer, so we make lots of approximations.
29:25
Speaker 1: It would be very convenient to have a limit on
29:27
Speaker 1: how fast information you could move, because if there wasn't
29:30
Speaker 1: a limit, if information could move at the speed of light,
29:33
Speaker 1: if you could shoot a death gun in one galaxy
29:36
Speaker 1: and instantaneously kill someone on the other side of the universe,
29:39
Speaker 1: then every time you're doing an update to the universe,
29:42
Speaker 1: to step it forwards in time to figure out what
29:44
Speaker 1: happens next, you need to scan through the whole university.
29:48
Speaker 1: Is somebody's going to shoot a death ray, Whereas if
29:50
Speaker 1: you have a limit on the speed of information, you
29:52
Speaker 1: only need to search within a certain space to see
29:54
Speaker 1: what's going to happen that's going to affect this person,
29:57
Speaker 1: or this alien or this rock. So it would be
29:59
Speaker 1: very very convenient. In a similar vein quantizing the universe,
30:03
Speaker 1: saying there isn't an infinitely small particle or a space
30:07
Speaker 1: can't be divided into infinitely small pieces would be very
30:10
Speaker 1: convenient because it would mean there's a minimum distance that
30:13
Speaker 1: you need to analyze in your simulation. When we do
30:16
Speaker 1: a simulation here in real science, for example, we usually
30:19
Speaker 1: create a granulated description of what's going on and we
30:23
Speaker 1: don't simulate things smaller than that, And how small we
30:25
Speaker 1: go depends on the problem we're solving. If, for example,
30:28
Speaker 1: you're trying to simulate a hurricane, you might not simulate
30:31
Speaker 1: anything smaller than a water drop. You don't really care
30:34
Speaker 1: what's going on inside the water drop. The water drop
30:36
Speaker 1: itself is your basic unit. If you're stimulating galaxies, you
30:39
Speaker 1: probably don't go smaller than an individual star. You don't
30:42
Speaker 1: really care about what's going on inside that star, or
30:45
Speaker 1: even on the planets around it, because they have no
30:48
Speaker 1: influence on how the galaxy is formed. So having a
30:51
Speaker 1: minimum unit to your universe is very convenient for doing
30:54
Speaker 1: those calculations. So Rodrigo and Pedro are suggesting, Hey, are
30:58
Speaker 1: these clues that the people who wrote our simulation have
31:01
Speaker 1: taken some shortcuts? This makes the simulation hypothesis more likely.
31:05
Speaker 1: And I would say the answer is no, because we
31:08
Speaker 1: don't know anything about the meta universe. Remember that when
31:12
Speaker 1: we write a simulation of another universe, we can make
31:15
Speaker 1: up whatever rules we like. Sure, one popular thing to
31:18
Speaker 1: do is to simulate our own universe to probe it,
31:20
Speaker 1: but you can also create any crazy kind of universe
31:23
Speaker 1: with any physical laws. You want, there is literally no limit.
31:27
Speaker 1: And what that means in principle is that by studying
31:30
Speaker 1: the physical laws of our universe, you gain no insight
31:34
Speaker 1: at exactly zero clue about the physical laws of the
31:38
Speaker 1: universe on the outside, the real universe that's running our simulation.
31:42
Speaker 1: And that means we don't know anything about computers in
31:45
Speaker 1: that universe, and we have no idea what's hard or
31:48
Speaker 1: what's easy for those computers. Everything I've just laid out
31:51
Speaker 1: is basically assuming we have simple, classical computers just like ours.
31:55
Speaker 1: But if they have a very different universe, the whole
31:58
Speaker 1: concept of a computer could be very different, and what's
32:01
Speaker 1: easy and what's hard in those computers could be totally different.
32:04
Speaker 1: And so if you want to be really strict about it,
32:06
Speaker 1: I would say, we can't learn anything about the nature
32:08
Speaker 1: of that universe from examining our own. You might wonder,
32:12
Speaker 1: We'll hold on a second. Don't we have a quantized universe?
32:15
Speaker 1: Doesn't that limit the kind of things we can calculate?
32:18
Speaker 1: Isn't the fact that our universe is quantized limit the
32:21
Speaker 1: kinds of things we can simulate, forcing us to only
32:23
Speaker 1: simulate quantized universes. Doesn't that mean if we're quantized, then
32:27
Speaker 1: probably the meta universe that's simulating us is also quantized.
32:31
Speaker 1: Not exactly. It's possible using quantized computers to simulate non
32:36
Speaker 1: quantized universes. You can, for example, on a quantized computer,
32:41
Speaker 1: write down the equation of a perfect circle a continuous circle,
32:46
Speaker 1: which is not quantized. The equation for that is pretty simple, right,
32:49
Speaker 1: it's x squared plus wise squared equals sum number, and
32:52
Speaker 1: that's a representation. Remember computers in the end our representation. Yes,
32:56
Speaker 1: they're moving information around. What that information means depends on
33:00
Speaker 1: the context. You know that that information represents stars in
33:04
Speaker 1: a galaxy or drops of water in a hurricane, but
33:07
Speaker 1: somebody else just looking at the bits doesn't necessarily know
33:09
Speaker 1: what it means. So the power of the simulation depends
33:13
Speaker 1: on the interpretation of it. I'm knowing what that information represents,
33:17
Speaker 1: and so we can represent almost anything. You're going to
33:19
Speaker 1: arrange bits to describe a classical unquantized universe, even if
33:24
Speaker 1: you're making a computer that is quantized. So unfortunately, I
33:27
Speaker 1: don't think that we can learn really anything about the
33:30
Speaker 1: nature of the meta universe, or if it exists, by
33:33
Speaker 1: studying the nature of the physical laws in our universe,
33:37
Speaker 1: but super fun question. Thanks very much for thinking about that.
33:40
Speaker 1: And hey, if you disagree with me, write me an
33:42
Speaker 1: angry email two questions at Daniel and Jorge dot com.
33:45
Speaker 1: I will pass it on to the programmers of our universe.
33:48
Speaker 1: I got one more really fun question, so stick around
33:51
Speaker 1: just after this break. All right, we're back and this
34:06
Speaker 1: is Daniel and I'm answering questions from our awesome listeners,
34:10
Speaker 1: who are really looking great these days. I love that
34:13
Speaker 1: new shirt you've got. By the way, thanks everyone for
34:15
Speaker 1: sending your questions. Please don't be shy. I promise it's fun,
34:18
Speaker 1: will be gentle. We are very friendly to our listeners.
34:20
Speaker 1: If you have a question, please please please write to
34:23
Speaker 1: us two questions and Daniel and Jorge dot com. I
34:26
Speaker 1: love that little ding when I get a new email. Well,
34:29
Speaker 1: here's a question from the other side of the world
34:31
Speaker 1: from Andreas of Sweden. Hey, guys, UM, So, I'm wondering
34:35
Speaker 1: if you had full control over space related funding for
34:39
Speaker 1: the next couple of decades or so, what would be
34:42
Speaker 1: your top three projects to focus on, what would bring
34:47
Speaker 1: the most knowledge for the buck, so to say, Um,
34:50
Speaker 1: For example, Sola Grabbity, lens drilling, into your ropes, oceans,
34:55
Speaker 1: housing humans permanently on Mars, etcetera. I would love to
34:59
Speaker 1: hear your thoughts on which projects you would focus on.
35:04
Speaker 1: Thanks Andreas from mess all right, Andreas, thank you very
35:08
Speaker 1: much for this question. You have unleashed my science fantasy budget.
35:12
Speaker 1: I would love to think about what it would be
35:15
Speaker 1: like to get to be in charge of the science budget,
35:18
Speaker 1: or more than that, to get to be in charge
35:20
Speaker 1: of how big the science budget is relative to other things.
35:24
Speaker 1: But I warned you this is gonna be depressing because
35:27
Speaker 1: when we're done, we're gonna have to go back to
35:28
Speaker 1: reality where the science budget is a tiny little slice
35:32
Speaker 1: of what governments spend their money on. And it's frustrating
35:36
Speaker 1: and depressing to me because I like to imagine this
35:39
Speaker 1: alternative universe where we do spend more money on science,
35:42
Speaker 1: because it's easy. If you wanted to know more about
35:46
Speaker 1: the universe, it's very simple. You've just got to spend
35:49
Speaker 1: more money. All the science agencies at every government around
35:52
Speaker 1: the world, when they put out a call for proposals,
35:55
Speaker 1: they get really really clever ideas for very very smart,
35:58
Speaker 1: hard working people, and they have to say no to
36:02
Speaker 1: most of them. If you're at the National Science Foundation.
36:05
Speaker 1: People send you crazy ideas they've been working on four
36:08
Speaker 1: free four years about ways we could learn incredible deep
36:11
Speaker 1: secrets about the universe, and mostly you got to say
36:14
Speaker 1: no to almost every single one of them. Why don't
36:18
Speaker 1: we just say yes to more of them? We are
36:20
Speaker 1: literally in the candy shop of the universe. We have
36:24
Speaker 1: pockets bulging with money and we're just spending pennies. It's
36:28
Speaker 1: incredible to me what we could learn the alternative history
36:31
Speaker 1: of the world if we had spent more money on
36:33
Speaker 1: science for the last fifty years. What we could already know,
36:37
Speaker 1: What deep secrets about the universe we are clueless to
36:39
Speaker 1: just because we spent money on warships instead. It drives
36:44
Speaker 1: me crazy. So thank you Andrea's for letting me spend
36:46
Speaker 1: a moment thinking about what do we like to live
36:48
Speaker 1: in that alternative universe where scientists, or at least me,
36:52
Speaker 1: got to decide what we were spending our money on.
36:55
Speaker 1: So I like the projects that you suggested, solar gravity, lens,
36:59
Speaker 1: your upo oceans, humans on Mars. Those are fun, but
37:03
Speaker 1: I think top of my list if I got to
37:05
Speaker 1: decide what we spent money on, would be a massive
37:08
Speaker 1: program to build more space telescopes. These telescopes sit in
37:12
Speaker 1: Earth's orbit or nearby and just gather information about the universe.
37:17
Speaker 1: We talked earlier in the podcast about how much information
37:20
Speaker 1: there is and we are capturing just a tiny slice
37:23
Speaker 1: of it. Like we have looked out into the universe,
37:26
Speaker 1: but we have not seen very far because seeing far
37:29
Speaker 1: requires looking for a while. Like things that are very
37:32
Speaker 1: far away in the universe are distant, and that means
37:35
Speaker 1: they are not very bright, and so their photons are rare.
37:38
Speaker 1: Like at the source, they are pumping out a bunch
37:41
Speaker 1: of photons. They could be very very bright where they are,
37:43
Speaker 1: but those photons drop in intensity as they get further
37:47
Speaker 1: from the source, Like there's no change in the number
37:49
Speaker 1: of photons, but the number of photons per area per
37:53
Speaker 1: square meter, for example, drops as you get further and
37:56
Speaker 1: further away, so that by the time you're twelve billion
38:00
Speaker 1: light years away from that galaxy, you're maybe getting one
38:03
Speaker 1: photon a minute or one photon an hour, and so
38:06
Speaker 1: to see it you have to point your telescope at
38:08
Speaker 1: that spot in the sky for a while. That's why,
38:11
Speaker 1: for example, what's called the Hubble deep field is so
38:14
Speaker 1: astounding and so beautiful because they just pointed the Hubble
38:18
Speaker 1: at one point in space for hours and collected all
38:21
Speaker 1: the light, and they were able to see more distant
38:24
Speaker 1: galaxies than anybody has ever seen before. And what's going
38:28
Speaker 1: on out there in the distant universe in just like
38:30
Speaker 1: another direction of space that we haven't even looked at.
38:33
Speaker 1: We don't know because we don't have enough eyeballs to
38:36
Speaker 1: look everywhere at the same place. So I would spend
38:40
Speaker 1: so much money on so many more telescopes and point
38:43
Speaker 1: them in so many directions. You know that scientists have
38:45
Speaker 1: to compete for time on the Hubble, And there are
38:47
Speaker 1: many many great ideas, great uses for the Hubble and
38:50
Speaker 1: the other space telescopes that never come to be just
38:53
Speaker 1: because there isn't enough time on them. And so there's
38:57
Speaker 1: all the information and it's hitting the Earth. These photons
39:00
Speaker 1: are coming here anyway, they're just not being seen. Nobody
39:04
Speaker 1: is gathering them, so that information literally going in the garbage.
39:08
Speaker 1: So I would spend a lot of money, hundreds of
39:10
Speaker 1: billions of dollars if I could, to build a whole
39:13
Speaker 1: fleet of space telescopes just to look out at the
39:16
Speaker 1: sky and gather that information rather than just letting it
39:19
Speaker 1: hit a rock and get ignored. There's so many secrets
39:23
Speaker 1: about the universe we could learn if we just looked,
39:25
Speaker 1: So let's build some more eyeballs. So that's my number one,
39:29
Speaker 1: is building a massive program of new space telescopes. Number
39:33
Speaker 1: two would be to explore our neighborhood. There's so much
39:37
Speaker 1: going on in our Solar System that we do not understand.
39:40
Speaker 1: There are so many places in our Solar System where
39:43
Speaker 1: there could be life, like right now in the oceans
39:47
Speaker 1: of Europa, and under so many frozen crusts of moons.
39:51
Speaker 1: We've never been to Uranus moons, for example. So the
39:54
Speaker 1: second plank of my personal science program would be a
39:56
Speaker 1: very aggressive robotic exploration of the Solar System. Basically, I
40:01
Speaker 1: want to visit every planet. I want to have orbiters
40:04
Speaker 1: around every planet, taking detailed pictures of its surface and
40:07
Speaker 1: measurements of its magnetic field and internal composition. And I
40:11
Speaker 1: want to land on every rocky surface in the Solar System.
40:14
Speaker 1: No moon should go unexplored. One of those moons could
40:18
Speaker 1: very well have life living under the surface. So I
40:21
Speaker 1: want to land on Europa and drill into the core.
40:24
Speaker 1: I want to land on every single moon. I want
40:26
Speaker 1: to land on Pluto. I want to take samples and
40:29
Speaker 1: bring them home. You know that the only samples we
40:32
Speaker 1: have that are not from Earth are from the Moon
40:35
Speaker 1: or a few rocks that fell off of Mars and
40:38
Speaker 1: came to Earth. We don't even have on Earth any
40:41
Speaker 1: rocks from Mars. Yet. We do have an elaborate program
40:44
Speaker 1: of Mars sample return which might bring us some rocks
40:47
Speaker 1: in the next ten years. But I want rocks not
40:50
Speaker 1: just from Mars, but from Mercury, but from Venus, but
40:54
Speaker 1: from Pluto, but from every moon on the Solar System.
40:58
Speaker 1: Imagine the science we could do where if you could
41:01
Speaker 1: have samples from all those places and compare them and
41:03
Speaker 1: study them and look for microbes and understand the chemical composition.
41:07
Speaker 1: What a treasure trove of information. We are just in
41:10
Speaker 1: the dark. We are making guesses about what's going on
41:14
Speaker 1: out there in the Solar System and under those rocks
41:16
Speaker 1: because we just don't know. And the only thing that
41:20
Speaker 1: limits us from doing it is money. Like, we know
41:23
Speaker 1: how to do this. It's not that it's easy, it's hard,
41:26
Speaker 1: it's technical, it's complicated, but we can do it. I mean,
41:29
Speaker 1: you saw a NASA, for example, fly helicopter on Mars.
41:32
Speaker 1: They know how to do this stuff, and if they don't,
41:34
Speaker 1: they will figure it out. And the money spent on
41:37
Speaker 1: figuring it out will also reveal other things, will generate
41:40
Speaker 1: new technologies. So if the only obstacle to learning these
41:44
Speaker 1: deep secrets and having this much science fund is funding,
41:48
Speaker 1: I really don't get why we're not doing it all right,
41:50
Speaker 1: But you ask for my top three projects. Number three
41:53
Speaker 1: on my list would be a massive system of gravitational
41:57
Speaker 1: wave detectors. This is a brand new way to look
42:00
Speaker 1: the universe, and for a long time it seemed like impossible.
42:03
Speaker 1: How could we possibly detect these super tiny little ripples
42:06
Speaker 1: in the fabric of space itself. When people were working
42:10
Speaker 1: on this in the late nineties, I was actually applying
42:12
Speaker 1: to graduate school and trying to decide where to go
42:14
Speaker 1: and what to study, and I was thinking about astronomy
42:16
Speaker 1: or astrophysics or particle physics. And I visited a program
42:19
Speaker 1: where they were doing searches for gravitational waves, and I
42:22
Speaker 1: remember thinking, this is nuts. These folks are never going
42:25
Speaker 1: to see anything. It's impossible they could ever develop a
42:28
Speaker 1: system so sensitive that they could see these things. Well
42:31
Speaker 1: I was wrong, and they won the Nobel prize, So
42:34
Speaker 1: congrats to them. It's wonderful. And what they've done is
42:37
Speaker 1: they've opened up a new way to look at the universe,
42:40
Speaker 1: not just with our eyeballs and with photons, but with
42:42
Speaker 1: gravitational waves. And we can see the universe in a
42:45
Speaker 1: different way using gravitational waves than we can with photons
42:49
Speaker 1: because gravitational waves are not absorbed. They can pass through anything.
42:53
Speaker 1: I mean, they scatter and they can reflect, for example,
42:56
Speaker 1: of the hidden really dense objects. But they're very different
42:58
Speaker 1: from photons and so they can tell us things that
43:01
Speaker 1: photons cannot. So it's like a whole new kind of eyeball,
43:05
Speaker 1: not just more eyeballs. And we have gravitational wave detectors,
43:08
Speaker 1: but they're kind of small and they're not as sensitive
43:11
Speaker 1: as they could be. So there's this fantastical, hilarious, awesome,
43:15
Speaker 1: wonderful science fiction project called Lisa, which is essentially a
43:18
Speaker 1: gravitational wave detector in space. The idea is that you
43:23
Speaker 1: have these three satellites out there in space that keep
43:26
Speaker 1: a fixed relative distance to each other, and when a
43:28
Speaker 1: gravitational wave passes, it stretches space a little bit between them,
43:33
Speaker 1: and they can measure this because they're shooting lasers back
43:35
Speaker 1: and forth to measure the distance between these satellites. So
43:39
Speaker 1: it sounds ridiculous, it sounds crazy, it sounds expensive. All
43:42
Speaker 1: those things are true, but it's also possible and it's
43:45
Speaker 1: something people who are really working on. And again, the
43:48
Speaker 1: limitation really is just time and money. So I would
43:52
Speaker 1: fund that as my number three. I'm in charge of
43:54
Speaker 1: the science budget program. And you might wonder, like, wow, Daniel,
43:58
Speaker 1: that does sound expensive. Yeah, and it might be that
44:00
Speaker 1: I've just proposed a trillion dollars of spending on science.
44:04
Speaker 1: But you know what, Every dollar we spend on science
44:08
Speaker 1: is a dollar that goes to education, It goes to
44:11
Speaker 1: people who are working on these things. It reveals secrets
44:15
Speaker 1: about the universe, and all that money is spent here
44:18
Speaker 1: on Earth. Like you might wonder, why are we spending
44:20
Speaker 1: money sending robots to the moons of Jupiter instead of
44:24
Speaker 1: building more housing for the poor. Yes, we should build
44:27
Speaker 1: more housing for the poor, and we should send robots
44:30
Speaker 1: to the moons of Uranus because that's an investment in ourselves.
44:34
Speaker 1: Every dollar we spend on these projects comes back to
44:38
Speaker 1: us because it creates more educated people, it creates more knowledge,
44:41
Speaker 1: decreas more love for the universe, and it creates new technology.
44:45
Speaker 1: If you believe in humanity and in our capacity to
44:49
Speaker 1: understand the universe and to explore it, then you should
44:51
Speaker 1: invest in science. And that doesn't mean taking money away
44:55
Speaker 1: from other things. It means, frankly, borrowing money from the future.
44:59
Speaker 1: It means taking out loans to spend this money because
45:02
Speaker 1: it pays for itself. It absolutely does. Every time we
45:06
Speaker 1: invest in basic research, it transforms our economy in ways
45:10
Speaker 1: we cannot anticipate, in ways we cannot expect. The only
45:13
Speaker 1: thing we can anticipate is that it will. So what
45:16
Speaker 1: is the next crazy discovery about the universe which will
45:19
Speaker 1: transform the very nature of our lives and our economy
45:23
Speaker 1: and make us all much richer so that we can
45:25
Speaker 1: all afford housing and food. We don't know, of course,
45:28
Speaker 1: we don't know. It's exploration, but the only way to
45:31
Speaker 1: get there is to fund basic research. For those people
45:34
Speaker 1: who are wondering why I didn't talk about humans on Mars,
45:37
Speaker 1: I think that's mostly ridiculous. I think terraforming Mars is
45:41
Speaker 1: a huge project which would take much more than just money.
45:44
Speaker 1: We need to figure out how to get enough CEO
45:47
Speaker 1: two on the planet to keep it warm enough without
45:49
Speaker 1: poisoning humans. We need to generate oxygen, which will take
45:52
Speaker 1: microbes millions of years, so I think that's not impossible,
45:56
Speaker 1: but it's not just a question of money. So my
45:59
Speaker 1: top three pitch would be a massive space telescope program,
46:03
Speaker 1: aggressive robotic exploration of the Solar System, and new space
46:06
Speaker 1: based gravitational wave detectors. So thank you so much, Andreased
46:10
Speaker 1: for letting me think about that and letting me fantasize
46:13
Speaker 1: about an alternative universe where a scientist president gets to
46:16
Speaker 1: set the amount of science spending and decide what it
46:19
Speaker 1: gets spent on. Probably we'll never experience that in our universe,
46:23
Speaker 1: but we can continue to hope. Thank you everybody for
46:27
Speaker 1: sending in your questions, and to those of you who
46:28
Speaker 1: are just passively listening, that's all right as well. Thank
46:31
Speaker 1: you for lending us your questions, your ideas, your curiosity
46:35
Speaker 1: about the nature of the universe. I hope that one
46:38
Speaker 1: day we all find answers to all of our questions.
46:41
Speaker 1: Thanks for listening. Tune in next time. Thanks for listening,
46:52
Speaker 1: and remember that Daniel and Jorge Explained the Universe is
46:54
Speaker 1: a production of I Heart Radio. For more. Podcast from
46:58
Speaker 1: my heart Radio, visit the i Heart Radio, Apple Apple podcasts,
47:02
Speaker 1: or wherever you listen to your favorite shows.