All Episodes

March 5, 2024 43 mins

Daniel talks to Matt Strassler about how everything is vibrating, and his new book "Waves in an Impossible Sea" (Part 1)

See omnystudio.com/listener for privacy information.

Mark as Played
Transcript

Episode Transcript

Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:08):
Hey, Daniel, are we made out of particles or waves?

Speaker 2 (00:11):
M That depends on what depends on what you mean
by particle and what you mean by wave.

Speaker 1 (00:19):
That's a very particular answer.

Speaker 2 (00:22):
Well, I'm not just gonna wave my hands when I
answer a question.

Speaker 1 (00:25):
I would have thought that a particle physicists would have
leaned into the particle answer.

Speaker 2 (00:29):
Well, I do have kind of a particle brainwave about it.

Speaker 1 (00:32):
I think you're just trying to wave me off.

Speaker 2 (00:34):
In particular.

Speaker 1 (00:50):
Hi, I'm poorhe Mae, cartoonist and the author of Oliver's
Great Big Universe.

Speaker 2 (00:54):
Hi, I'm Daniel. I'm a particle physicist and a professor
at UC Irvine, and i'd like to think i'm I'm
also a wavular physicist.

Speaker 1 (01:02):
A wavuler. I don't think I've ever heard that word.

Speaker 2 (01:06):
I just made it up. Man, aren't physicists great at
naming things?

Speaker 1 (01:09):
Would it be more perpetsey you're a wavy physicist or
a waiver physicist?

Speaker 2 (01:14):
I got wavy hair, and I do sometimes waver about
my decisions.

Speaker 1 (01:18):
There you go, waves dominate your life and you didn't.

Speaker 3 (01:22):
Even know it.

Speaker 2 (01:25):
I'm waving everybody right now.

Speaker 1 (01:26):
Yeah, she'd waveright it? But anyways, Welcome to our podcast
Daniel and Jorge Explain the Universe, a production of iHeartRadio.

Speaker 2 (01:33):
In which we try to dig deep into the nature
of the universe around us. How is it all put together?
How does it all work when you zoom in on
the tiniest little bits? What are they actually like? Are
they little bits of sand? Are they weird? Quantum ripples?
Are they both? Are they neither? Are they something else
completely different? Our goal in this podcast is to tackle

(01:54):
these questions directly and do our best to explain everything
we do and don't understand to you.

Speaker 1 (02:00):
That's right. It's an amazing universe full of mysteries out
there for us to look out and ponder about and
ask questions about. But sometimes the biggest mysteries are within us,
inside of us, and they're about our very nature of
how we exist.

Speaker 2 (02:15):
That's right, because we are part of the universe. When
we ask what is the universe made out of? How
does that actually work? We also want to understand ourselves.
One of the deepest goals in physics, but something we
don't often say directly is that we want to understand
how everything works so well that we can understand ourselves.
That we could build up from our picture of the

(02:36):
microscopic world, the tiny little quantum particles, all the way
up to our microscopic world, which means us and ice
cream and blueberries. Somehow, we hope that revealing the nature
of the universe on the tiny level will give us
a crack and understanding why we're here and what to
do with ourselves.

Speaker 1 (02:53):
Yeah, and it's a huge challenge to connect what's happening
at the microscopic level to what's happening at the cosmic
and universe level. That is the goal of science to
make those connections and give us a sense of the
big picture of how it's all put together.

Speaker 2 (03:07):
That's right, because we assume that there is a way
it's all put together, that the universe is following rules,
that it has a nature that we could know, that
we could understand, that we could maybe even describe with
our primitive human mathematics and predict and manipulate it in
a way that might improve our lives. That at least

(03:27):
is the goal of trying to understand the universe. Whether
or not we've made any progress is another question.

Speaker 1 (03:33):
It seems like we've done pretty well, Like we discovered
our bodies then we discovered we're made out of cells,
and then we discovered those cells are made out of molecules,
and those molecules made out of atoms, and then those
atoms made out of particles. I feel like we've drilled
down pretty deep into the makeup of the universe.

Speaker 2 (03:49):
Yeah, that's pretty impressive how far we've gone and how
we've been able to make some connections between how things
happen on a small scale and what we experience on
a larger scale. Even just like the idea of germs
and disease, that tiny little bugs swimming around in the
air and in our bodies can have a big effect
on our experience. The whole germ theory is sort of

(04:10):
a triumph of the idea that the microscopic world controls
the macroscopic world.

Speaker 1 (04:15):
Wait, do you mean like a virus can have an
impact in our lives? News flash, isn't it all made
up by scientists?

Speaker 2 (04:23):
M I'm not even going to touch that.

Speaker 1 (04:26):
Yeah, you don't want to touch those viruses.

Speaker 2 (04:30):
I'm not going to take a deep breath of that.
But at the forefront of human knowledge, what you described
as the latest bit of our understanding, you know, the
particles that make us all up. What are those really?
We had a whole podcast episode where we dug into
the question like what is a particle? Because a particle,
in some sense is an extrapolation from things we find
intuitive in our world, little bits of stuff. The particulates

(04:54):
we think make up our world just sort of like
extended down to the very very tiny. We find when
we get down there is that particles obey very different rules.
And it's almost a bit of a scam to use
a word that relies on our classical intuition to describe
something that happens at the quantum world.

Speaker 1 (05:11):
WHOA, WHOA are you saying that physics it's sort of
like a scam.

Speaker 2 (05:14):
I'm saying physics has been kind of lazy in using
its words, and that we're often borrowing words that have
like intuitive baggage that's misleading. And when we talk about
particles and we talk about waves, we're often not really
clear about what we actually mean when we're talking about
these things, and I think we're often misleading people.

Speaker 1 (05:33):
It seems like we drilled down right beyond the atom
into the particles that we're made out of, but then
we sort of hit a wall in terms of our understanding,
because once you get to these tiny quantum particles, you
get to ask, like, what are these particles, what are
they made out of? What's their origin?

Speaker 2 (05:47):
Yeah, and we have a mathematical description that works really,
really well. Quantum field theory can describe these interactions and
make predictions and tell us what's going to happen in
our experiments. With challenging is developing an intuitive picture in
your mind for what's going on the microscopic scale, And
that's always going to be challenging because what's happening down

(06:08):
there has no analog in our experience. There are some similarities, like, yeah,
electron is a little bit like a little bit of stuff,
and ripples in a quantum field are a little bit
like what happens in your baptub when you splash your
hands around. But those are like stepping stones towards a
real understanding. They aren't the deepest, most intuitive understanding of

(06:29):
the world.

Speaker 1 (06:30):
Yeah, what's going on at those deep levels? And what
is matter and energy actually made out of? And so
to the on the podcast, we'll be tackling the question
is the universe made of waves?

Speaker 2 (06:46):
Are you made of waves? Man?

Speaker 1 (06:48):
I am a little wavy. I guess right now, I
think I'm in a lull. For sure.

Speaker 2 (06:55):
It feels like that question through you for a wave.

Speaker 1 (06:57):
Yes, I wasn't able to serve my way to a
with answer. I wipe out, physics wipeout.

Speaker 2 (07:04):
I think this question is interesting because we know fundamentally
that all the laws of quantum field theory are wave equations.
Like at the heart of it, everything is described in
terms of waves. But we have this intuitive sense that
we're made of stuff, and we like to think of
ourselves as built of little bits of stuff, maybe lashed
together with forces. But it's hard to imagine ourselves as

(07:26):
like made of waves, that you and I are both
just like waves in the universe.

Speaker 1 (07:32):
Well, I feel like you know someone who listens casually
to physics. You know, you sort of grow up learning
about this idea of whether things are made out of
particles or waves, and you know that there was a
big debate at the turn of the last century, and
then you sort of learn about the idea of the
wave particle duality, like things are both particles and waves.

Speaker 2 (07:52):
I think the wave particle duality is well intentioned, but
very confusing and often misleading because it gives people the
idea that electrons or particles or photons or whatever switch
between being waves and being particles, Like they are both,
but sometimes they're being a particle and sometimes they're being
a wave. I think that's very confusing and misleading.

Speaker 1 (08:15):
Well, it's definitely confusing, but I guess you know, as
a casual consumer, I've always just accepted that things are
like two things at the same time, Like, isn't that
kind of the nature of quantum physics, Like things can
be two things at the same time, and if you
look at it one way, it's a particle, and if
you look at another way to wave. Isn't that kind
of the basic thing that physicists have been teaching.

Speaker 2 (08:37):
I like that you apply quantum superposition to like our
understanding of it, Like, well, I understand it this way,
and I understand it that way in a quantum mechanical sense,
Like I have two ideas in my mind at the
same time.

Speaker 1 (08:48):
Yeah, it's a bad point and a good point at
the same time. It's both deep and shallow at the
same time. I am both smart and dumb when it
comes to quantum physics.

Speaker 2 (08:58):
I'm going to give you a good explanation and a
bad explanation at the same time. Hold them both in
your heads. No, I think what's confusing about that is
that physicists say that, but they mean something specific when
they say the word particle, and it mean something specific
when they say the word wave, And I don't think
it's understood that way.

Speaker 1 (09:16):
What do you mean? What do they mean when they
say particle? What do they mean when they say waves?

Speaker 2 (09:20):
When they say particle, really they just mean you've made
a localized measurement of something, not that it's like converted
into a little bit of stuff, and it's not flying
along through space with a definitive path and location and
momentum and velocity and all the things you expect of
a little bit of stuff. And when they say wave,
what they really mean is it still has uncertainty that

(09:42):
you haven't collapsed it. You haven't asked the universe to
tell you where it is. You haven't made a measurement it. Really,
it's all still just waves. Even this idea of a
particle being localized in one spot like a dot on
a screen, a measurement you make, that's also a property
that a quantum wave can have. It can collapse into
one local spot.

Speaker 1 (10:00):
And so that's where this question comes from, Like is
the universe made out of waves? Are you sort of
making the argument that the word particle doesn't make sense
and it's really all just waves?

Speaker 2 (10:09):
In the end, the word particle makes sense if you
give it a sensible definition, but everybody seems to have
a different idea of what particle means. So it's sort
of like an overloaded word that's more confusing than clarifying.

Speaker 1 (10:20):
Oh, I see, So people shouldn't like major in a
field if the name is confusing or misleading, is that
what you're saying, or devote their whole careers to it.

Speaker 2 (10:30):
Hmm, I see, you're walking me down the garden path here. Absolutely, yeah, exactly.
You shouldn't have like a PhD and a professorship in
a word that you don't even understand what it means.

Speaker 1 (10:40):
Yes, I totally agree.

Speaker 2 (10:42):
That would be ridiculous. Anybody who did that should be
mocked and ridiculed.

Speaker 1 (10:45):
Yes, mocked, ridiculed, and also given a podcast.

Speaker 2 (10:51):
Absolutely totals agree.

Speaker 1 (10:55):
But yeah, I mean, if this idea that everything is
a wave and the word particle doesn't make sense, doesn't
that sort of challenge your whole you know, feel the
research and the whole particle collider idea.

Speaker 2 (11:06):
I'm just going to switch over to being a waveular.

Speaker 1 (11:08):
Physicist, yeah, or a wavy physicists.

Speaker 2 (11:11):
Yeah, we're just going to collide waves from now on.

Speaker 1 (11:12):
Man, Waveler, I don't even know how to process that word.
Why would you use that word?

Speaker 2 (11:18):
It seems like the natural adjective version of waves.

Speaker 1 (11:23):
But is it an adjective wave?

Speaker 2 (11:25):
You aler?

Speaker 1 (11:26):
Yeah, if you're a particle physicist, that doesn't mean that
particles inadjective.

Speaker 2 (11:30):
Particles describing physics there right, I guess I could be
a particular physicist.

Speaker 1 (11:34):
Yeah, that's what I mean. That's why Waveler feels so weird.

Speaker 2 (11:36):
Oh I see, all right. Well, in the conversation with
our guest today, he introduces another word wave it cull
because he also doesn't like the word particle.

Speaker 1 (11:45):
Oh my goodness. Why don't you have everyone come up
with their own words? M and let's do science that way.

Speaker 2 (11:51):
That's basically what we've done so far, and it's not
working very well.

Speaker 1 (11:56):
Everyone's like, I came up with a word, he's mine. No,
he's fine.

Speaker 2 (12:00):
It's a basic principle of language that words are supposed
to have meetings, but we've been pretty bad about that
in physics.

Speaker 1 (12:06):
Well, I vote for wavy wavy physicists.

Speaker 2 (12:10):
All right, I'm going to position my department for a
change of my title.

Speaker 1 (12:14):
Well, today we're doing something a little bit interesting, which
is we're jumping right into an interview that you did
with a professor of physics who has a new book out.

Speaker 2 (12:22):
That's right, my colleague, professor Matt Strassler. He's a theoretical
physicist and listeners to the podcast might already know him
because he's the author of a pretty well known blog
on particle physics called of Particular Significance. He should be
called of wavular Significance.

Speaker 1 (12:37):
Yeah, it seems like he might be invalidating his own blog.

Speaker 2 (12:41):
And he's an excellent writer for a general audience. And
he's got a new book out called Waves in an
Impossible See where he shares his vision for how the
world works on a microscopic scale.

Speaker 1 (12:52):
Interesting he didn't name it Wavecles in an Impossible See.

Speaker 3 (12:56):
Cale.

Speaker 2 (12:57):
I suggest everybody get a popsicle and going enjoy the book.

Speaker 1 (13:01):
Yeah, there you go. All right, Well, what are some
of the things you talk about with Professor Strassler.

Speaker 2 (13:06):
We try our best to sketch out the argument in
his book Walk You through the principles that lead you
to a new vision for how the universe works, from
relativity to fields to waves, and how that's all crucial
for getting a real understanding of how the Higgs field works.

Speaker 1 (13:24):
I see it's not just a being handwavy about things. Well,
I can wave to dive into it. So here's Daniel's
interview with Professor Matt Strassler, author of the book Waves
in an Impossible Scene.

Speaker 2 (13:40):
Okay, so then it's my great pleasure to introduce the podcast.
Professor Matt Strassler a friend and colleague. Matt is a
theoretical physicist and an author. He's been a researcher at
the Institute for Advanced Studies, a professor at the University
of Pennsylvania, University Washington, and at Rutgers University, as well
as a visiting professor at Harvard. He's very well known
in the academic particle phys community for as many new

(14:01):
ideas and influential concepts, such as the possibility of a
hidden valley, which isn't about a new kind of ranch dressing,
but the idea that significant parts of the universe could
be mostly shut off from us, hidden by our limited
ability to interact with them. He's also widely respected for
his scientific writing. His blog of particular Significance is an
example of scientific writing for a general audience at its finest.

(14:22):
This isn't just more the same, where you'll find a
few tired analogies recycled. Matt writes with a unique voice
that demonstrates his deep intuitive understanding of the physics, which
he can convey with a crisp but logical and accessible explanation.
Listeners to the podcast who write to me to ask
for more details on virtual particles or the Higgs field
will often get a response back that includes a link

(14:43):
to some of Matt's blog posts, because it's some of
the best explanations out there for these weird and tricky concepts.
So I was very happy to hear, of course, that
Matt decided to write a book, and having just finished
reading it, I can tell you that it lives up
to my hopes. It's clear and compelling journey through the
complex topics that gives you a new way of looking
at the world and thinking about the complicated ideas you

(15:04):
often hear about waves and particles and fields. And mass
and all that stuff. So Matt, welcome to the podcast.

Speaker 3 (15:10):
Thank you so much. Daniel, it's a pleasure to be here.

Speaker 2 (15:13):
So tell me first why you decided to write a book.
What question is this book an answer to?

Speaker 4 (15:19):
Well, I think, as with many books, the question that
the book ended up being in the answer to is
not the question I was originally trying to answer. Not
that the questions aren't connected. But as you and many
of your readers and listeners will know, there was a
big event in particle physics back in twenty twelve, and
that was the discovery of the famous Higgs boson, which

(15:42):
is a type of particle that the news media likes
to call the God particle, and most physicists think this
is a ridiculous thing. But so much for science journalism.
We're stuck with that. And the thing which was one
of the tasks of science journalists and scientists at the
time of that discovery before or to explain why it
was that physicists were looking for this thing, was to

(16:04):
explain why it's important to do that. Why are we
spending a substantial amount of money and a lot of
people's time to go looking for this one type of
particle who cares?

Speaker 3 (16:16):
Right?

Speaker 4 (16:16):
So obviously this was something that scientists thought a lot
about how to explain what is fundamentally a tricky concept.
And there were some explanations that were really not so great,
but there were.

Speaker 3 (16:30):
A few that were not bad, and one of them that.

Speaker 4 (16:34):
Took on a life of its own and sort of,
you know, people started to take it kind of seriously
at the level that it started appearing often in science
journalism and even started appearing in long form books about
the Higgs particle correctly explained that the Higgs particle isn't
really the big deal here. The Higgs particle was a
means to an end. We were trying to understand something
much deeper, which is called the Higgs field. The Higgs

(16:58):
field is something that present throughout the universe. It has
an enormous impact on our lives, a secret impact, but
nonetheless something we can't live without.

Speaker 3 (17:08):
And so the better.

Speaker 4 (17:10):
Explanations said, Okay, don't worry about the Higgs particle, that's
just a means to an end. We really want to
understand the Higgs field. Then the next question was, all right, well,
if the Higgs field is important, why is that? And
the answer is that it has something to do with
how certain elementary particles get mass, and mass turns out
to be essential in our universe for us, because if

(17:33):
electrons didn't have mass, there would be no atoms. I
don't need to explain beyond that point how important the
Higgs field is.

Speaker 2 (17:41):
I like Adams, atoms are good. Yeah, I'm planning to
have atoms for dinner tonight. For example.

Speaker 4 (17:46):
You may have them for the rest of your life,
I certainly hope so, so, yes, we can't really do
without them. But then came the next question, which was,
all right, if the Higgs field gives mass to things,
how does.

Speaker 1 (18:00):
It do it?

Speaker 4 (18:02):
And that's where things went a little off the rails again,
not because anybody was trying to, you know, pull the
rug over people's eyes or somehow try to mislead, but
to actually explain it takes some cleverness and it takes
a little while, and so if you're asked to give
a sound bite, you can't quite do it. So the

(18:23):
SoundBite that people came up with was that the way
it works is kind of like this. The Higgs field
is like a substance that fills the universe like a soup,
or like snow or like molasses.

Speaker 2 (18:38):
I've heard the molasses one many times.

Speaker 3 (18:40):
Yeah, the molasses is a great one.

Speaker 4 (18:42):
Right. You kind of imagine yourself swimming through molasses and
somehow breathing through it, and it slows things down, just
as molasses would do, or soup.

Speaker 3 (18:50):
What do you try to get through it? It slows
you down.

Speaker 4 (18:53):
And because it slows things down, that's how it gives
things mass.

Speaker 2 (18:56):
And to be clear, this is the common popular science
explanation that we're not happy.

Speaker 4 (19:01):
This is unacceptable, and the reason that's unacceptable is that
it not only mis explains how the Higgs field works,
but it does so in a way that contradicts probably
the single most important principle of physics that you have
to understand to be able to understand pretty much anything

(19:24):
about how the universe works, and that is the principle
of relativity. That's the principle that explains why the Earth
can go round the Sun for billions of years without
slowing down and crashing into the Sun. That's the principle
that explains why light can move across the universe and

(19:44):
atoms can move through the universe all you know, over
enormous distances, and if you abandon the principle of relativity
because you want to try to explain how the Higgs
field works. You're giving up something even more important to
explain something and not even really explain it.

Speaker 3 (20:02):
So that just doesn't make said.

Speaker 2 (20:04):
I hear that question from our listeners all the time
because they hear this explanation and then they're like, wait
a second, having mass doesn't mean you slow down, Like
you can be really massive and fly through the universe
without slowing down. Exactly, how is the Higgs slowing things down?
And they're right, and that's really any sense, And then
I link them to your blog. But this was the
initial motivation you're saying for like, why you wanted to
write this book. You felt like it was a missing

(20:26):
part of the story here. Is that what the book
ended up being about.

Speaker 4 (20:29):
Also, well, in a way, yes, in that I think
it does provide for the first time a complete and
coherent and correct explanation as to what the Higgs field
is actually doing.

Speaker 3 (20:42):
And in particular, not only.

Speaker 4 (20:43):
Does it not have anything to do with slowing things down,
it doesn't have to do with motion at all, and
it gives mass to electrons via an indirect route, which
in order to understand one has to first understand what
electrons actually are, and that, in the end, in a way,
is more what the book was about, essentially by necessity,

(21:06):
because in order to explain what the Higgs field does,
I have to really explain how the universe works in
its most basic sense, and that requires understanding relativity, not
in detail, not with the math, but the basic conceptual framework.
And it also requires understanding a little bit about the
basic framework of quantum physics.

Speaker 2 (21:26):
All Right, I have a bunch more questions for Matt
about how the universe works and how we can really
understand the Higgs field correctly. But first let's take a
quick break. Okay, we're back and we're talking to Professor

(21:51):
Matt Strassler, author of the new book Waives in an
impossible see, who wants us to really understand how the
universe is all made of ways and how that's crucial
to understanding how particle physics and the Higgs boson works.
And I will say that I was surprised when I
started reading the book because I expected it to be
about how the universe is all made of waves or

(22:11):
how the Higgs field actually works. And then you start
off with Galleo in relativity, and I'm like, wow, we
are going back to the beginning. Matt is rebuilding all
of physics for us. But by the end I could
tell why you had done it, because you relied on
crucial details in that understanding to give a cogent explanation
for how this all works. So kudos to you.

Speaker 3 (22:32):
Thank you, Daniel.

Speaker 4 (22:33):
But as you say, the key to writing the book
in a way was to I mean, obviously, the universe
is enormous in many different senses of the word, but
you could write ten books explaining it. The key in
a sense was to pick out those things which were
most critical and explain them really well, and to try
not to explain too many things, but to really go

(22:54):
to the heart of the matter, in hopes that a
reader would come away not onunderstanding everything, but understanding a
few things really well, so that at the end what
the Higgs field is doing and how it gives mass
to things would make sense. And I try to do
it without watering things down. You know, I'm not using

(23:15):
math in it, but I am trying to make sure
the concepts are a complete story.

Speaker 2 (23:20):
Absolutely, And for those of you who want to understand
the higgs Field in a deep, conceptual and intuitive way.
Really encourage you to get the book and to read
it carefully and to think about it, and to write
us with questions if something in there doesn't job with
your understanding, because that's a learning moment. On today's podcast,
I hope that we can get a sketch of these ideas.
Of course, we can't do justice to the whole book

(23:41):
and all of its careful explanations, but maybe we could
do an abbreviated version to give people an idea of
this important way of thinking about the universe that makes
the Higgs field make actual sense rather than molasses sense.
So let's start at the beginning. You started with relativity
for a reason, because we need to understand relativity to
understand what it is the higgs field is doing and
is not doing. What is the principle of relativity that

(24:03):
people really need to.

Speaker 3 (24:04):
Understand well in a way.

Speaker 4 (24:06):
You know, the word relativity comes with Like most words
that we physicists use when we try to explain what
we do to the wider public, it comes with baggage.
And the cultural baggage of the word relativity couldn't be heavier, right,
I mean, we're talking Einstein. But what most people don't
realize is that the principle of relativity goes back to

(24:28):
Galileo and the year sixteen thirty two. And this is
when Galileo wrote down for a reading public that you
cannot tell just by looking around you, or by watching
other objects around you, or by doing simple experiments, how
fast you're moving. And this is hard enough for us

(24:52):
to think about. I mean, you know, if you're in
a car, if you're moving thirty miles an hour, of
the car bumps around a little bit, Whereas if the
car isn't moving at all, well you don't feel any bumps.
So I mean, we're used to the idea that if
you're traveling faster, the bumps are more and you can
tell how fast you're moving. But we forget that at
this very moment, where I am seated in my chair,

(25:14):
and many of your readers are seated in their chairs
or doing something that means that they're not moving relative
to their room. They are nevertheless going around the axis
of the Earth as it spins. They are going round
the Sun once a year, at twenty miles a second.
The Sun and Earth and the whole solar system are

(25:35):
going around the center of the galaxy at one hundred
and fifty miles per second, and we don't feel it.
And this was Galileo's realization based on some experiments that
he did, but it was central in the history of
human thought because up until that point there were many

(25:56):
brilliant thinkers, including Tycho Brahe, who was the person who
collected the data that Kepler then used to figure out
how the solar system works. And bri was after Copernicus
by fifty years. So Copernicus said, you know, the Earth
goes round the Sun, but people didn't necessarily believe him because,
as Brahe himself said around sixteen hundred, look, I mean

(26:17):
if the Earth were moving, we'd feel it. And he
was wrong, not because he was dumb, but because this
principle of relativity is so weird and so counterintuitive that
whatever space is, whatever the empty space that we call
the vacuum or just deep space is, we can move through.

Speaker 3 (26:41):
It as though it's nothing.

Speaker 4 (26:42):
And then you might say, well, okay, maybe it is nothing.

Speaker 3 (26:44):
What's the big deal?

Speaker 4 (26:46):
And that's a perfectly good answer until Einstein comes along
and says, no, it can't really be just nothing, because
it can expand I mean when we say the universe
is expanding, we don't mean that there's stuff flying out
into empty space. We mean empty space is growing. And

(27:08):
when we say gravity is a manifestation of the shape
of empty space, we're saying that empty space is something
that can bend. And the big Nobel Prize of twenty seventeen,
the big discovery of twenty fifteen was the observation of
gravitational waves. Gravitational waves are ripples in space, So you

(27:32):
can't really explain away the idea that, okay, the reason
we move through space without feeling anything is that space
is nothing, because then you have to explain how can
nothing ripple and stretch and do all these crazy things.
So now you have a puzzle. How can it be

(27:53):
that Galilee is right that you can't tell how fast
you're moving even though you're moving through a substance or
something that acts like a substance. I mean, maybe it's
not a substance. We haven't ever you know, bottled it
and sold it in stores. But it's very strange that
this should be true. So this was a place to

(28:14):
start because it forces us to confront a sort of
fundamental confusion that we seem not to be able to
detect whether we're moving through this substance, but it does
seem to be a substance. And this has been confusing
since the time of Einstein. I don't know whether I
should say he was confused about it. That I think

(28:35):
would be unfair, but he understood this was a fundamental
puzzle or conceptual. Maybe puzzle is even the wrong term
because it's not clear it needs a solution, but it's
a conceptually strange thing about the space that makes.

Speaker 3 (28:52):
Up the universe.

Speaker 2 (28:53):
And just to make it like explicit, the thing that's
confusing is, if you're moving through space, why can't you
measure your speed relative to space? If space is a thing, right,
if it has properties, it can ripple, it can expand,
and you can put numbers in it, why can't you
measure your velocity relative to space, which would give you,
like a way to absolutely measure your velocity around the Sun,

(29:14):
or around the galaxy, or inside a ship or inside
a car. That's the central puzzle here.

Speaker 4 (29:19):
In a way, there's two interesting puzzles, and they're related,
and yet the answer to the two puzzles is contradictory
or seemingly contradictory. The first puzzle is why can we
move through space without slowing down? If it's a substance,
I mean, we can't move through air without slowing down.
If that's why airplanes need engines, and you can't move

(29:40):
through water without slowing down, that's why submarine isn't itine?
And one potential answer to that has to do with
the idea that we are made from waves, that the objects,
namely the electrons and quarks and other fundamental particles, really
should be understood as waves. And one way to see
that is that if you ask yourself whether you and

(30:01):
I could move through solid rock, Well, that's a ridiculous idea, right,
killed instantly if we tried to do that. And yet
seismic waves from earthquakes they just go right through the earth.
In fact, scientists use them to probe the inside of
the earth. The waves go right through Why because they're
part of the rock. They're the rock doing something right.

(30:24):
Sound waves it's the same thing. Why is it that
an airplane needs engines and sound waves don't need engines.
Soundwaves can travel thousands of miles and they don't slow down.

Speaker 3 (30:34):
Why not?

Speaker 4 (30:35):
Well, they're the air in action. So the idea that
we might be made from things that are really sort
of the universe in action waves in some sense of
the universe, arises very naturally from these observations. Maybe the
reason we don't feel any friction, any drag when we

(30:55):
move through the universe is that we're kind of made
of it in some gunal sense.

Speaker 2 (31:00):
You're saying we are wiggles in the universe, the way
seismic waves are wiggles in rock.

Speaker 4 (31:05):
I will qualify that by saying there's a little more
complexity to it, but that's the basic idea. Now, the
simplest ripples in empty space are precisely gravitational waves, and
we're not made from those. But it is possible for
space to have sort of unseen properties, unknown properties which
could have waves in them, and we might be made

(31:25):
from those. That's a way of possibly interpreting what we're
made of. And for example, in string theory, although this
is not limited to string theory, that is a common
way of understanding space.

Speaker 3 (31:37):
It's more complicated.

Speaker 4 (31:38):
Specifically, it has extra dimensions and weird shapes, and so
there are properties of space that are not obvious to us,
at least through our senses and waves that have to
do with those properties might be the things that we
are made from.

Speaker 3 (31:52):
That's speculation.

Speaker 4 (31:54):
But the idea that we are made of waves that
are somehow made of things that are integrated into the universe,
that follows from the math that we use today in
a sense that's less speculative. It's a way of interpreting
the math that we already have. And so that's one
puzzle and one possible solution that oh, okay, the unuse.

Speaker 3 (32:15):
Really is a substance.

Speaker 4 (32:16):
It's got these properties, there are waves in those properties,
and we're made from those waves. Okay, great, We can
still worry about the fact that it's not so easy
to build objects out of waves that you and I
are familiar with. You've never seen a cathedral built from
sound waves, and you've never seen an elephant made out

(32:36):
of seismic waves. There is this question how are you
going to make things out of waves? But we'll come
back to that because that's the question of quantum physics
and how electrons can be waves in.

Speaker 3 (32:48):
The first place. But there's a second puzzle that has
to do with space. So again the puzzles that had
to do with space.

Speaker 4 (32:55):
The first one was how can we move through it
if it's a substance without feeling any drag, without slowing down.
And one solution is, we're made of waves.

Speaker 2 (33:05):
Of this substance.

Speaker 4 (33:06):
Okay, great, But then you ask yourself, fine, it's a substance,
let's go feel it, let's make a bottle of it,
let's track.

Speaker 2 (33:13):
It down, Let's measure our velocity relative to it exactly.

Speaker 4 (33:17):
And there are many ways that you can think of
doing that. So for us moving through air, that's not difficult.
You use a wind meter that tells you how fast
the air is moving relative to you, or vice versa.
If you want to know how fast you're moving through
the water on a boat, just put your hand in
the water and you'll feel, you know, the water will
pull your hand in some direction, and which direction it

(33:38):
pulls your hand in and how hard will depend on
how fast you're moving through the water. That's not quite
a fair comparison, though, if I've just told you that
we're made of waves of that stuff, right, So then
you want to ask yourself, well, supposing you were a
creature made out of ocean waves, how would ocean waves
know how fast they're moving through the water, Which is

(33:59):
a weirder question, and we're not used to asking that.

Speaker 3 (34:02):
But you can ask it.

Speaker 4 (34:04):
And one way that ocean waves can tell is they
can look at other ocean waves as they come by,
at least in principle, right, if you're made out of
ocean waves and here comes your friend made out of
ocean waves, they're coming in a different direction, how fast
are they moving? And you can tell from looking at
how they behave how quickly you yourself are moving through
the water. And one way to say this is hidden

(34:26):
in the notion of the speed of sound. So in air,
when we measure the speed of sound and we say
it's eleven hundred feet per second, well, it's a speed.
What is that speed relative too? And the answer is
it's relative to the air. The speed of sound is
eleven hundred feet per second relative to the air. And

(34:46):
so if the air we're blowing by you at some velocity,
if there's some strong wind, well then the sound waves
going in the direction of the wind will pass you faster.
Then the sound waves go in the opposite direction because
they're being pulled along by the air as it flows
by you. And if you're a supersonic jet, you're out
running your own sound. The sound is moving eleven hundred

(35:07):
fet per scond relative to the error, and you're moving faster.
But with light, when we talk about the speed of light,
what is that relative to And in the analogy that
we've been talking about, you might imagine that, well, it
should be whatever it is one hundred and eighty six
thousand miles per second relative to space or whatever it
is that fills space that makes up the thing in

(35:29):
which light is a wave. But that's not how it works. Somehow,
the way the universe works is that the speed of
light is measured relative to an observer who is trying
to measure it, and not relative to space. And the
importance of that is that it allows for something bizarre,

(35:53):
which is that no matter how fast you're moving, no
matter how fast some object that's emitting light is moving,
the speed of light when it passes you is always
the same from all directions and from any source. That's
not true for sound, it's not true for ocean waves.

(36:13):
And those facts are directly tied with the fact that
you can tell whether you're moving what relative to the
substance of air or water. But the way it works
for light, despite all the analogies between waves of sound
and waves of light, and of course our ability to
perceive them.

Speaker 3 (36:30):
It just works differently.

Speaker 2 (36:31):
All right, we're going to get even deeper into this,
but first we're going to take a quick break. We're
back and I'm talking to Professor Matt Strassler, author of

(36:53):
Waves and an Impossible Sea. Is that a consequence of
the nature of space you always measure the speed of
light to be the same thing, because you can't measure
your speed relative to space. Or is it go the
other direction that because you have to measure the speed
of light the same for all observers, therefore you cannot
measure your velocity relative to space.

Speaker 4 (37:11):
It's a great question because in a sense, the cause
of relation isn't clear. Yeah, we know these are facts,
we know they are related, but we don't fundamentally know
which thing should be considered sort of primary and which
things should be considered a consequence. And so, just to
bring everything full circle, what Einstein was doing when he

(37:35):
proposed that the speed of light was a constant from
all observers point of view, which had not occurred to
anyone prior to him, was deeply tied with this inconsistency
between what relativity ala Galileo says that you should not

(37:56):
be able to measure your speed and what light waves
tell you, which is well, light as a wave's just
like sound as a wave, So there should be some
substance relative to which light speed can be measured. You
can't have it both waves, because if light does have
a speed relative to a substance, and you can measure
your speed relative to the light, then you can also
measure your speed relative to the substance, and then Galileo's

(38:19):
relativity is no longer true. You can tell how fast
you're moving through the universe. And what Einstein said was
maybe Galileo's principle is still true, and there's something about
the way you're thinking about light waves that is fundamentally
different from how it works for sound waves.

Speaker 2 (38:36):
So it's truly Galileo's theory of relativity that Einstein protected
correct or rescue.

Speaker 4 (38:42):
That's right, that's exactly now. Einstein's theory of gravity is
a bigger deal. And not to say this was a
small deal. I mean, saving galileos relativity was a major achievement.
But it's important to understand that fundamentally what Einstein was
doing was saving Galileo's principle at the expense of the
notion of space and time, which seemed obvious in order

(39:03):
to make it possible for light to do something that
seemed impossible. And it does leave us with this notion
of space as this substance like thing with respect to
which we cannot measure our motion.

Speaker 2 (39:19):
And we don't really have a great explanation for why
that is.

Speaker 3 (39:22):
Right.

Speaker 2 (39:23):
We can see that as a consequence of the speed
of light being constant for all observers, but we don't
have like a ground truth the fundamental reason for why
a space has this property based on what it is. Right,
sort of going backwards, we're saying it just has this
property because we know it can't do this thing.

Speaker 4 (39:39):
Yeah, I mean, it's an experimentally derived fact in the end, right,
it was Einstein's idea that maybe space and time works
this way. But the reason we know it's true is
one hundred years of experiments and doing things like building
giant particle accelerators, which would not work at all if
these facts weren't true in detail. So the fine tuning

(40:01):
of an engineered particle accelerator requires that Einstein's formulas be
correct to many decimal places, and so these are not
speculative ideas anymore. Even though when Einstein wrote the down
at that time it was a proposal, he didn't know
it was true, but it turns out that it is.

Speaker 2 (40:21):
But there's a difference between being well established and being understood.
Absolutely can say, well, we know this is correct and
describes the universe, but gosh darn it, we don't understand
what it means about the universe right correct.

Speaker 4 (40:33):
There are many speculations about what it might tell us
about space and time that would take us far afield
from the story of this book. In my book, I've
tried to avoid speculations and stick to the things that
we know, because I think it's really important for anyone
who wants to read this speculative stuff. I mean, there's
wonderful ideas out there, which most of which, of course
will turn out to be wrong, but they're based on

(40:55):
these fundamentals, and so you really have to understand the
fundamentals to grasp what deep problems physicists are grappling with.
And what's wonderful and exciting and challenging about what I've
just told you about space is that you don't need
to be a mathematician or an expert in physics to

(41:16):
understand the problem, to understand how deep a puzzle this is.
And that's part of why I thought a book like
this could really work. And I think it's important that
as many people as possible appreciate just how spectacular these
types of problems are. It shouldn't hurt your head to

(41:39):
learn about the problem, and yet it should hurt your
head when you try to understand the problem in just
the same way it hurts mind.

Speaker 3 (41:46):
It's not as though.

Speaker 4 (41:47):
These things are hard because it's difficult to understand what's strange.
They're hard because any human being, including the experts, find
this strange.

Speaker 2 (42:00):
And so I want to share with listeners the picture
that you paint in the second half of the book
how the universe works, so that we can better understand
the Higgs field and the context of this discovery of
space and light and how things wiggle, and you were
mentioning it earlier, how everything is made out of waves.
This is all super wonderful and fascinating and making me
rethink how the universe around me works and how it's

(42:23):
all made of tiny waves. But before we dig into
the rest of this and understand the Higgs boson. We're
going to have to pause here and pick up this
discussion in the next episode, Part two of my conversation
with Professor mattz Stressler, where we'll talk about how the
universe is actually all made of waves and why that's
vital to understanding what the Higgs field is and what

(42:46):
it does how it gives us all mass. So hold
on to your thoughts about how the universe works and
check out Matt's book Waves in an Impossible See available
everywhere right now, See you next time for the second
part of this conversation. For more science and curiosity, come

(43:08):
find us on social media where we answer questions and
post videos. We're on Twitter, Discorg, Insta, and now TikTok.
Thanks for listening, and remember that Daniel and Jorge Explain
the Universe is a production of iHeartRadio. For more podcasts
from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever
you listen to your favorite shows.
Advertise With Us

Follow Us On

Hosts And Creators

Daniel Whiteson

Daniel Whiteson

Jorge Cham

Jorge Cham

Show Links

AboutRSS

Popular Podcasts

Stuff You Should Know

Stuff You Should Know

If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.

The Nikki Glaser Podcast

The Nikki Glaser Podcast

Every week comedian and infamous roaster Nikki Glaser provides a fun, fast-paced, and brutally honest look into current pop-culture and her own personal life.

Music, radio and podcasts, all free. Listen online or download the iHeart App.

Connect

© 2024 iHeartMedia, Inc.