Everything in the universe might be the same particle from the Big Bang | Michelle Thaller

0:00 There are some words that are really easy to throw around.

0:03 And in science, they become interestingly complicated.

0:05 People often say, you know, do you believe such and such is true?

0:09 You know, do you believe the Big Bang is true?

0:11 You know, do you believe that the idea of multiple universes is true?

0:15 You know, a lot of these things.

0:17 And when you're a scientist, you're aware that what what you're doing

0:21 is you're constantly trying to approach reality.

0:24 You're trying to get closer and closer to describing something very well,

0:28 but you know you're not all the way there yet.

0:31 And it's quite possible that we never will be.

0:34 It's quite possible that human beings with our limited senses,

0:37 our limited brains even,

0:39 you know, won't really know what the true nature of reality is.

0:43 It's one of these kind of wonderful things that, you know, truth can change.

0:47 You know, 100 years ago,

0:48 people were certain that the universe was not expanding,

0:51 you know, and of course, we found out that it was.

0:53 And you have to be able sometimes to take your very precious images,

0:57 you know, models of what the universe is like, about what reality is like,

1:01 you know, even about what the definition of truth is,

1:04 you need to make sure that you're ready

1:07 to change when better information comes on board.

1:11 [Narrator] The strange universe astronomy reveals to us.

1:15 There's sort of two words that float about,

1:18 there's astronomer and astrophysicist.

1:19 And, you know, it kind of depends on whether you're trying

1:21 to put on a more friendly or formal vibe, I think.

1:23 They really, these days, mean the same thing.

1:25 I think there was a time when there was sort of a separation of duties.

1:29 There were people that, say, 100 years ago would map the stars

1:32 and create all these wonderful catalogs of stars.

1:35 And you might call those astronomers.

1:36 You know, the, the name is from astronomi, to name the stars.

1:40 And then there were people that tried to figure out what the stars

1:44 were and how they worked and what the science of it was,

1:46 you know, behind all that.

1:48 Those would be the astrophysicists.

1:49 And these days, the two studies are really the same.

1:53 If you're an astronomer or an astrophysicist,

1:54 you pretty much do the same thing these days.

1:56 The word that was probably the best word, astrology,

1:59 to study the stars, that one was already taken.

2:02 A lot of the questions that I get from members

2:05 of the public are these vast conjectural questions like,

2:08 you know, is there a multiverse?

2:09 Or what happened before the Big Bang?

2:11 So from my doctorate, you know, from my research, I studied binary stars.

2:15 You know, I studied two stars that orbit each other,

2:18 and most stars in the universe are like that, by the way.

2:21 And in the case of my stars,

2:23 they had these wonderful colliding winds of high energy

2:26 particles that produced these giant shocks in the sky.

2:29 The fun thing is that, for a while at least, and maybe today,

2:33 there are some stars in the sky that I've probably

2:35 spent more time with than anybody else in the world.

2:37 You know, I observed them for hours and hours

2:40 trying to figure out how these colliding atmospheres worked.

2:43 In the case of myself, I'm an observational astronomer.

2:46 I went to observatories all over the world.

2:49 About 25 years ago when I was most active in research,

2:52 I did a lot of research in Australia,

2:54 in Arizona, the Kitt Peak telescopes, Mount Stromlo in Arizona.

2:57 I also used a lot of satellite data.

3:00 I had data from x-ray satellites and the Hubble Space Telescope.

3:03 I actually got some time.

3:05 You see, as an astronomer, you are allowed to write into these observatories.

3:09 It usually happens once a year.

3:11 And there is a panel that basically assesses, you know,

3:14 what would all these people around the world

3:17 like to do with the Hubble Space Telescope?

3:20 And this panel of astronomers actually decides,

3:22 you know, who should get priority.

3:24 One of the things about being an astronomer

3:26 is you end up doing a lot of writing.

3:28 You end up doing a lot of writing asking for time on these telescopes,

3:32 and then hoping that your proposal gets selected.

3:34 Another thing is you end up asking for a lot

3:37 of time to write grants from money to support your work.

3:39 You know, if you get some time on the Hubble Space Telescope,

3:42 often it comes with an amount of money

3:44 to support the time you're gonna do that research.

3:46 So it turns out that being an astronomer,

3:49 all of the training is about the math and the physics and the computer science.

3:53 And then what you actually do day to day is often a lot of writing and a lot

3:58 of trying to organize proposals and grants

4:00 and how you're gonna support yourself doing your science.

4:03 And then if you work for a large organization like NASA,

4:06 some of your time as well is usually assigned to some specific mission.

4:11 You know, some specific space telescope where you're

4:13 going to be helping clean up the data,

4:15 figure out how we're going to issue a call for proposals,

4:18 organize the panels that are going to vet

4:20 and look at all these different things.

4:23 So in a way, you become kind of an administrator, a lot of meetings.

4:26 I think that, you know,

4:27 the normal life cycle of astronomer's probably 80% like business person,

4:30 a lot of meetings, a lot of grants, a lot of budgets.

4:34 But then, at least for me, there really was this time,

4:38 it doesn't happen so much when you're a more mature astronomer,

4:40 but when you're really young and out

4:42 in the field and making your own discoveries,

4:44 it really does feel like you're sort of alone with the night

4:46 sky all by yourself up on top of that mountain.

4:49 And you're seeing things coming down through your telescope that, you know,

4:53 it's a minor advance, but, you know, no human being has ever seen before.

4:58 And it's a wonderful feeling of empowerment and, sort of, you know,

5:01 kind of collaborating with the sky and seeing what we can figure out.

5:05 One of the things is when you get a doctorate,

5:08 you have to produce some kind of original research,

5:11 something that's never really been done before,

5:13 and that's not as hard as it sounds.

5:15 That sounds very intimidating.

5:16 I mean, how am I gonna think of an idea that nobody's ever thought of before?

5:20 But nothing in astronomy happens alone.

5:21 You know, what happens when you're a graduate student after college is you will

5:26 join a professor doing his or her research with them sort of as an apprentice.

5:30 And then over time, as you get more familiar with the work,

5:34 they will give you a little piece of that research, like, "Hey,

5:36 you go ahead and take this part over yourself."

5:38 You don't really need to think of things entirely,

5:40 you know, just off the top of your head

5:43 and come up with brilliant ideas out of nowhere.

5:45 You start little by little, working with a group of astronomers.

5:48 And then slowly, you start to ask your own questions.

5:51 You know, maybe they've never had time on a telescope

5:53 to look up this little bit of it, you know, or this little bit of it

5:56 over here is a new question nobody thought of.

5:59 And eventually you realize that what you're

6:00 doing is something that hasn't been done before.

6:02 I guess there were probably about a dozen stars in the sky,

6:06 but there were three that I really, really focused on.

6:09 And in every case, these were binary stars,

6:12 and these were stars that were very massive, stars that were,

6:16 say, you know, anywhere between, like,

6:18 15 and 50 times the mass of the sun, big stars.

6:21 They actually only orbit around each other every couple of days,

6:24 or at most, about a week.

6:26 So these are very big stars in very close orbits.

6:29 And so it should make sense, these stars are pouring off, you know,

6:33 not only light, but high-energy particles,

6:35 this winded particles that we call stellar winds.

6:38 And then they collide in between these two stars.

6:41 Sometimes one of their winds will not be as strong as the other.

6:45 So the wind from one sort of overtakes the other one

6:47 and kind of blasts away the wind from the other one.

6:49 And as they turn around each other, you actually sort of have this wonderful,

6:53 kind of, three-dimensional view of how that shockwave goes all the way around.

6:57 And so I use a technique called tomography,

6:59 which is the same sort of thing you use in a CAT scan or, you know,

7:03 something like an MRI where you're trying to produce

7:05 a three-dimensional scan of inside the human body.

7:08 In this case, the instrument goes around you.

7:10 But in the case of the stars, the stars would go around each other.

7:13 And then I could use this sort of software mainly developed

7:16 for medicine to actually try to figure out the structure of these shockwaves.

7:20 This is, you know, just sort of work a day astronomy, you know, nothing,

7:23 you know, all that incredible or sexy about it,

7:26 but it helps you understand stars better.

7:28 It turns out that these shockwaves are responsible for producing

7:31 a lot of the molecules that we find in space.

7:35 You know, stars create, you know, atoms.

7:37 They fuse hydrogen into helium and then

7:40 eventually helium into larger atoms over time.

7:42 But these shockwaves, at least in the cooler parts of them,

7:45 can produce things like water, the water molecule.

7:48 And there are, you know, there are some binary stars, like,

7:51 there are some in the Orion Nebula that are

7:53 producing enough water in a single day along

7:56 these shockwaves to fill the oceans of the earth

7:59 like 60 times over in a single day.

8:01 Now, obviously this isn't liquid water.

8:03 This is water in a molecular form, pretty hot gas actually.

8:06 But that's where a lot of the molecules responsible

8:09 for life can come from, is from these shockwaves.

8:11 So it's a way of trying to figure out just little

8:14 by little how the universe really does work, how stars work.

8:18 So my research is much more observational, much more about stars.

8:22 I certainly took classes in cosmology, the study of the universe as a whole.

8:28 I took classes in quantum mechanics, you know,

8:30 graduate-level quantum mechanics, graduate-level electromagnetism, all of that.

8:33 People often start right off with the, you know, are there parallel universes?

8:37 And I'd rather they sort of ask me,

8:39 you know, what are the importance of binary stars?

8:42 There's honestly not all that many

8:45 astronomers by number that do theoretical cosmology.

8:47 You know, most of us are trying to figure out things like

8:50 how stars are born and how they like live their lives and die.

8:53 We're trying to figure out, what's left over after a star explodes,

8:56 a black hole, a neutron star?

8:58 Or we're trying to figure out how galaxies work, how many galaxies there are,

9:02 how do we observe them, how do they change over time?

9:05 There's only a few of us that are trying to answer questions like,

9:08 you know, what happened before the Big Bang?

9:10 Or, you know, are there multiverses?

9:12 We all study that to an extent.

9:14 And we all go to lectures at the conferences.

9:16 I love going to the ones on, you know, quantum theory and quantum gravity.

9:20 Most astronomers study things that are a bit

9:24 more concrete than that, very far away.

9:27 So it's often the case that, you know,

9:29 I'm giving some lecture on this, you know,

9:31 wonderful new images of Saturn from one of our spacecraft like Cassini,

9:35 and they're so beautiful, and we're learning things about the atmosphere.

9:38 And look at these pictures of these little moons we

9:40 took in the ring system and we're studying the ring system.

9:43 And we have a wonderful lecture, I turn to the audience and say,

9:45 "Hey, any questions?" You know, and somebody raises their hand.

9:48 And the first one is, you know, are there multiple universes?

9:51 Saturn.

9:52 In physics, at least for the last 100 years,

9:56 that has really challenged us to leave behind our human ideas of common sense,

10:03 the very definition and perhaps existence of space and time.

10:08 The whole idea about what is reality, what is existence,

10:12 what am I, is a very, very complex question now to answer.

10:17 I mean, to give you some ideas about

10:20 this, there are some things that are very simple.

10:23 Like, what is the interior of the sun like?

10:26 It's obviously something we've never directly observed,

10:28 but we see energy pouring out of the sun.

10:31 There are actually waves, almost like earthquake waves that go around

10:34 the sun that help us to study the interior, the way those waves travel.

10:38 But do we know exactly how the core of the sun works?

10:41 No, no, we don't.

10:42 There are things that we get pretty close to, but we

10:44 just don't really have the observational ability to do so.

10:47 But then there are questions like, what are space and time really?

10:53 For so long, we've just sort of taken it

10:56 for granted that space and time exist around us.

10:58 Time flows in one direction.

11:00 Space extends perhaps to infinity.

11:01 But then there was also a time when we didn't think that air was anything.

11:06 People didn't realize that we actually live, you know,

11:08 at the bottom of this wonderful ocean of air that is our atmosphere.

11:12 People took it for granted that air existed.

11:14 That was actually, you know,

11:15 proven in the 18th century that this was actually something.

11:18 Einstein showed us that space and time absolutely

11:22 cannot be the simple way we perceive them.

11:25 It all is related around the speed of light.

11:28 The speed of light is always constant to any observer.

11:32 One of the myths about Einstein was that he pulled

11:35 all of these amazing ideas just kind of, you know, out of his head from nowhere,

11:39 that he wasn't part of the scientific establishment.

11:41 Well, in fact.

11:42 He was a professor.

11:43 He was actually a graduate student trying to get

11:45 a job when he was working at that patent office,

11:48 but he had that miracle year where he came up

11:50 with the theories of special and general relativity among other things.

11:54 So here's an example about allowing yourself to define whether something

11:57 is true in kind of a bit more of an active way.

12:01 Isaac Newton was able to describe very, very well how gravity worked.

12:05 He was really one of the first people that said there's this force of gravity.

12:09 And he just said that it's a force.

12:11 This force permeates the universe.

12:12 And this is why the planet's orbit the sun.

12:15 You know, this is why apples fall from trees is they're reacting to this force.

12:19 And by using his equation of gravity,

12:21 you could calculate that force very, very well.

12:24 So you had this, you know, great thing, the force of gravity, the force exists.

12:29 It binds the universe together.

12:31 But then you have to ask the question, okay, what do we mean by that?

12:35 What is the force of gravity?

12:37 What is it really?

12:38 What causes it?

12:39 And it took Albert Einstein to say that what we think

12:42 of as gravity is actually a curvature of space and time.

12:45 Things have to follow space and time.

12:47 We are all embedded in the space and time of the universe.

12:51 So if that space and time has a shape to it,

12:54 a curve to it, we have to follow that.

12:57 Light has to follow that.

12:59 You know, light itself that has no mass

13:01 can actually bend and go into a black hole.

13:03 And that's because the light has to travel through space and time,

13:06 and the space and time itself is bent.

13:08 So all of a sudden there was this answer, what is the force of gravity?

13:13 It's a bending of space and time.

13:15 So is that it?

13:16 Is that the end of those questions that we can ask there?

13:19 Well, how about the rather obvious next one?

13:21 What is space and time?

13:23 Okay, there's this thing that Einstein called space-time,

13:25 that your space and time are sort of mixed together.

13:28 They're two sides of the same coin.

13:30 When you change one, the other has to change.

13:32 If you are in a gravitational field and space is bent, time actually slows down.

13:37 It actually affects time as well.

13:39 We know that these two things are bound together, but what are they?

13:43 Time can be different for different observers depending on your velocity.

13:46 If you're going very close to the speed of light,

13:49 as people observe you going by, they see your time is very slowed down.

13:52 If you're actually a photon going at the speed of light, time stops entirely.

13:56 So what do we mean by this thing called time?

13:59 And this is now what some of the major physicists of the world

14:02 are grappling with, and they're trying

14:03 to come up with some very interesting answers,

14:05 and I think the answers that will be very challenging for us.

14:09 Imagine being a physicist back in the early

14:12 1900s and having this young Albert Einstein tell you,

14:16 space and time are bendable.

14:17 You can change them.

14:18 You can manipulate them.

14:19 You might've thought they were crazy.

14:21 How about looking at space and time

14:25 instead as a consequence of quantum mechanics?

14:28 A lot of people have been saying

14:30 that relativity and quantum mechanics don't match, they don't work together.

14:33 And this is true.

14:34 This has been true since the beginning

14:36 of relativity and quantum mechanics about the same time.

14:38 Relativity says that if you have a certain amount of mass,

14:42 you can actually say space bends this much.

14:45 And quantum mechanics says that everything is down to probabilities.

14:48 The universe never has set answers,

14:50 but maybe the probabilities of a particle being here versus there.

14:55 Even the curvature of gravity must somehow be probabilistic.

14:58 And Einstein didn't like that.

15:00 There was no way to work that into his equations that actually,

15:02 you know, made them both work at the same time.

15:04 What if we were asking the wrong question?

15:07 What if we're not looking at two different things?

15:09 What if we could actually say that space-time

15:12 itself is a consequence of quantum mechanics,

15:15 not something separate from it, not two things that are clashing together?

15:19 And this is the idea now that perhaps quantum entanglement,

15:24 if you look at it correctly, is space-time.

15:28 Now, quantum entanglement isn't just a term you can throw off very, very easily,

15:32 but this is something that we have now observed

15:34 and been able to replicate in laboratories all across the world,

15:38 even in space actually.

15:40 If two objects interact together, they can actually sort of become,

15:43 in a sense, the same system under the laws of quantum mechanics.

15:47 So lemme just give you a very simple example of this.

15:50 A lot of people know the model of an atom

15:53 where you have this nucleus of protons and neutrons,

15:55 and the electrons can be in different orbits around there.

15:59 In fact, in a single orbit around the nucleus,

16:02 there can be two electrons, but those electrons can't be exactly the same.

16:06 You can't have two that are identical.

16:08 They have to have opposing spins, angular momentum.

16:11 It turns out you can have two electrons in each one of these orbits,

16:15 but the electrons can't be identical.

16:16 They have to be spinning in opposite directions.

16:19 It's a strange idea that electrons spin,

16:22 but at least you can say that there's some kind of intrinsic angular momentum.

16:25 What we think of as something spinning,

16:27 that's actually a property that a particle can have

16:29 whether or not there's actually like a physical little ball.

16:32 Electrons are not little balls,

16:33 but they do have a property of spin, of angular momentum.

16:36 You could have two of them in the same

16:38 orbit as long as they have opposing spins,

16:40 one spinning one way the other, there's spinning the other way.

16:42 So say that one is spinning, you know,

16:44 up and one is spinning down, the way my thumbs are pointing.

16:47 You know that these two electrons have to have different spins.

16:51 So what happens if you actually take them out of that system,

16:54 you take them away from the atom entirely?

16:55 And now you've got these two little electrons somewhere in space,

16:57 and you know that they have to have opposing

17:00 spins because they once were in that same orbit.

17:03 Well, okay, so now separate them.

17:05 Separate them by a couple of feet, maybe a couple of miles.

17:09 How about a couple hundreds of miles?

17:11 Maybe there's no limit.

17:12 We found out that if you use some sort

17:15 of energy to change the spin of one of these electrons,

17:18 the other one basically instantly knows that that's happened.

17:21 And it's not that there is a signal passing between one

17:25 of these to another because it doesn't travel even at the speed of light.

17:29 It's an instantaneous flip.

17:30 It's not a signal traveling because these two

17:33 things are basically the same quantum system.

17:35 In the rules of quantum mechanics, they are the same object.

17:39 So there's no signal really to travel.

17:41 To a quantum system, there really isn't any such thing as space or time.

17:45 It will adjust instantaneously because it's the same system,

17:49 whether it's microscopic or whether it's many thousands of miles apart.

17:54 They're the same thing.

17:56 Could it be that everything is entangled to everything else in some way?

18:00 Well, I mean, there once was a time when the universe was very small, you know,

18:05 the time right after the Big Bang where,

18:07 in a way, we were all kind of the same particle.

18:09 That particle has changed and expanded,

18:11 but is it possible to think that, in some way,

18:14 we're actually the same quantum system to everything in the universe and what

18:18 we perceive of as space and time is the degree to which we're entangled?

18:23 We're entangled more to things that are closer to us,

18:26 that have a chance to interact with us,

18:28 the air in this room, the space that's only outside in my yard.

18:31 I'm less entangled to things that I've not been

18:34 able to interact with much for a long time, things like distant galaxies.

18:37 I haven't been close to them since the beginning of the universe.

18:40 Einstein asked, what is gravity, really?

18:44 And now we have to ask, what is space-time really?

18:49 And we know it can't be as simple as the way we perceive it.

18:54 Maybe the underlying quantum reality of the universe is that everything,

18:57 in a way, really is still the same quantum system.

19:01 I've always thought when people think about alien civilizations

19:04 and they say they flying saucers and UFOs and spaceships,

19:06 I kind of wonder if the next step in really

19:09 understanding reality is that there's no such thing as distance.

19:13 And maybe a very advanced civilization that can somehow manipulate

19:17 that, you don't have to travel anywhere in a spaceship.

19:20 You simply figure out how you access

19:23 this entanglement of the rest of the universe.

19:25 Could it be that you are really

19:27 the same quantum system as everything in the universe

19:30 at once and that degree of entanglement is what we think of as space,

19:36 as time, as gravity?

19:38 That's an amazing idea,

19:39 and it's one that more and more people are starting to look at.

19:43 Do we know this is true yet?

19:45 No, this is still conjectural, but the physics is working very well.

19:48 And one of the promising things is

19:51 that the equations of gravity emerge now from quantum mechanics.

19:55 They're no longer general relativity, quantum mechanics.

19:58 They don't mix.

19:59 You start with quantum mechanics,

20:01 and gravity emerges from it, from the degree of entanglement.

20:05 So stay put for a couple more decades.

20:08 And like I said, maybe someday we're actually gonna

20:10 figure out what the underlying structure of this entanglement is,

20:13 and then we can actually move outside of space and time.

20:17 When you are pure energy, you have to travel at the speed of light.

20:22 A photon has to travel at the speed of light.

20:24 It can't go any other speed.

20:25 A photon can't exist in a state where

20:27 it's only moving at, say, 20 miles an hour.

20:30 It has to travel at the speed of light.

20:32 And when you're traveling at the speed of light,

20:35 you don't experience space or time.

20:37 You're probably familiar with Einstein's idea that as you go faster and faster,

20:40 closer to the speed of light,

20:42 time slows down for you compared to an observer watching you.

20:45 If I'm sitting here still on the Earth and I watch

20:48 somebody in a spaceship whizzing by at half the speed of light,

20:51 I see them very, very slowed down compared to me.

20:54 And when you're actually going at the speed of light itself, time stops.

20:57 That means that light does not experience space

21:01 or time in any kind of extended way.

21:04 All points in space are one, and all time, all points in time are one.

21:09 Time and space don't exist to a photon the way it does to us.

21:13 And yet I am made of something that you

21:16 can convert to photons and back and forth.

21:18 And I experience space and time.

21:21 I experience those as extended properties.

21:23 There's a duality to the universe, and I think this is going to become

21:27 one of the most important things for modern physics,

21:29 the next revolutions in physics.

21:30 Light around us, I mean, it's coming from the sun through my windows.

21:34 It's coming at me through, you know, the lights that we have in the studio,

21:37 doesn't experience the same universe I do.

21:40 To it, in a real way, the universe never expanded.

21:44 All points of time and space are still one from the perspective of a photon.

21:49 And I'm made of photons, kind of, but why do I experience space and time?

21:55 Space and time as we perceive them cannot be the end story.

22:00 There has to be a different perspective that shows

22:03 us a reality that our human brains don't perceive yet.

22:07 But the physics all around us, something as simple as light demands it.

22:13 The things that kind of give me chills is

22:15 just how little we understand the nature of reality itself.

22:17 If something bouncing off me right now

22:20 doesn't experience the universe as having even expanded, what does that mean?

22:24 So that equation, e= mc squared, I mean, it's useful.

22:28 You can use it to power nuclear reactions.

22:30 You can use it for particle accelerators,

22:32 but it actually sort of claws away the fabric

22:36 of reality itself and challenges us to ask what's underneath.

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