What everyone misunderstands about the Universe

Daniel talks to Zach Weinersmith about the most common misconceptions about our Universe.

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:08):
So the goal of physics is to understand the universe.
And on one hand, you could say we've been making
great progress. Look how far we have come. On the
other hand, you could say, look at all the mistakes
we've made. Every idea we've had about the universe has
been proven wrong, except for the current idea, which we're
also pretty sure is wrong. We just can't prove it yet.

Speaker 2 (00:46):
Hi.

Speaker 1 (00:46):
I'm Daniel. I'm a particle physicist and a professor at
UC Irvine, and I've always wanted to understand the big
picture of the universe. Frankly, I'm amazed that we can
understand any of it at all. And the history of
humanity is of misunderstandings, of making mistakes and fixing them
in a way that we hope bends gently towards the truth.

(01:07):
But as our ideas get more and more accurate, they
also get harder and harder to understand. From the ancient
myths about the way the universe worked to the crazy
predictions of general relativity, today's ideas are pretty hard to
wrap your brain around. And I find what I'm interacting
with folks in the general public and listeners of this podcast,

(01:28):
most of the questions and most of the misconceptions people
have when they write to me are about topics in cosmology.
How big is the universe? Where was the Big Bang?
How can we actually know the universe has a size
or an age, or all of these things. There are
quite a few ideas that are out there about how
the universe works that are not really quite right, but

(01:50):
yet are often repeated in popular science presentations. And so
today on the podcast, I want to talk about why
everyone misunderstands cosmology. And I'm not just talking about everyday
people out there, I mean scientists. We've basically been misunderstanding
the universe as long as there have been people. And

(02:12):
to help me break this down, I have a fun
guest and the author of a new book exploring the
history of cosmology from our first early mistakes and bad
ideas to our current probably wrong theories about how the
universe works. Okay, well, then it's my pleasure to introduce
to the podcast Zach Wiersmith. Zach is most well known

(02:35):
for being married to Kelly, the famous guest host of
this podcast. Zach, thanks very much for joining us today.

Speaker 2 (02:41):
Thank you very much. Just to be clear, I'm more famous,
You're just being funny.

Speaker 1 (02:49):
That's right. Zach is also the author of SMBC, a
hilarious webcomic that has no set characters or themes, but
just folks pun at thinkers in physics that can math philosophy. Basically,
Zach's job is to troll nerds everywhere. Together with Kelly,
he's the author of Suonish, a book that tells us
why future technology will mostly be disappointing, and they have

(03:10):
a new book coming out this fall called A City
on Mars, which is all about how living in space
will be dangerous and uncomfortable. You guys are really optimist,
aren't you.

Speaker 2 (03:19):
Oh yeah, yeah, Well we are the gatekeepers of the truth.

Speaker 1 (03:25):
And this is not Zach and Kelly's first experience on podcasts.
Zach also did a podcast which ended in twenty fourteen,
which was called The Wiener Smith Weekly. Is that right?

Speaker 2 (03:34):
The Weekly Wiener Smith released once every ten years.

Speaker 1 (03:36):
Do you think it's a coincidence that twenty fourteen is
the year you ended your podcast and also the year
podcasts took off.

Speaker 2 (03:44):
The coincidence is that my first child was born that year.

Speaker 1 (03:47):
Maybe it's hertful, but Zach is not here today to
talk about either. Those books or his podcast. He's here
today to talk about something else entirely. Zach has a
new book coming out on cosmology. Zach tell us the
title of your new book.

Speaker 2 (04:02):
The Universe a Bridged beyond the point of usefulness.

Speaker 1 (04:06):
So why did you write this book, Zach? What inspired
you to abridge the entire universe?

Speaker 2 (04:10):
Well, I actually have a whole series of books that
are not useful. It's a funny story, actually, So I
released a book of religion related comics, and kind of
as a joke, I abridged the whole Bible. The goal
was to do every book of the Bible in one sentence.
I got it down to like one to three sentences
per book of the Bible. The New Testament is much
more funny with short, clipped sentences because there are a

(04:32):
lot of letters. But that book, which was originally a gimmick,
like outsold the book. It was meant to be a
gimmick for by like ten to one, and so I thought,
I like money, and also this is fun. So I
did one that was abridging all of science, and then
one that was less popular but nearer and dear to
my heart, which was a bridging all of Shakespeare's sonnets,
and the newest one is abridging all of the universe,

(04:54):
and strictly speaking, it's more like abridging cosmology and its history.

Speaker 1 (04:58):
But I'm going with the what's this sort of special
mental challenge that comes in abridging in like boiling something
down to its essentials? You learn anything by a bridging
the Bible and Shakespeare that you applied to the universe.

Speaker 2 (05:10):
Yeah, to be honest, for me, it's really fun. So,
as you mentioned, like one of my hats is as
a researcher, which means, you know, just when you research
for a book, you become a very boring person who
reads very boring books that nobody else is reading because
you're trying to get a job done. And I try
to take the same approach to the extent I can
to these mini books. I mean, you know, I can't
spend a years on a single one, but I do

(05:33):
try to read like the actual literature, and I talk
to people like you who actually know what they're talking about,
because there's obviously no chance I'm going to like learn
the deep math in a short period of time, and
then I try to get to where I understand it,
and then can tell jokes about it, because it's very
hard to tell jokes about something that you don't at
least more or less understand, which is interesting, by the way,
I have this theory that everyone, instead of doing a thesis,

(05:54):
people should just like do a fifteen minute joke set
on it to actually prove they know what they're talking about.
So there are much of play is where on stuff
in retrospect, it's fairly basic where I thought I knew
sort of what the deal was, and then as I'm
writing and I'm like, I don't feel like I understand
this at the level I need to to explain it
to somebody else. And so the result of that was,

(06:15):
you know, a lot of talking to you and other cosmologists,
and then also just you know, doing reading. I've you know,
cosmology text, I'm trying to understand something like one of
the really hard things to understand a lot of this
is like why a particular finding was really important because
often it like interfaces with like cultural stuff.

Speaker 1 (06:35):
I think it's really fascinating to try to boil down
the whole history of cosmology because the approach you've taken
is not just like here's everything we understand today. But
here's how all of the ideas have developed. Here's like
what the original wrong ideas were, and then the later
wrong ideas, and now our latest probably wrong ideas. I
think that's a really fascinating approach, because, as you say,
at each moment we think maybe we've understood the universe,

(06:58):
and then later that's all thrown in the try.

Speaker 2 (07:00):
I think it's also interesting, at least for the way
my brain works, to go through the history of what
was thought, because it often makes much more clear why
we think something now. So you may have had this
experience when you're like explaining something from cosmology to someone
and they're like, but that's crazy. That doesn't make any
sense to me, And you're like, well, won, you should
have heard what we believed before. But two like, however

(07:24):
weird it is. We have all these weird threads, and
this is the idea that pulls them together. My sense
is a lot of people when they first hear about
dark matter just like, oh, it's just illuminate luminiferous ether
all over again. And these physicists, you know, but then
when you get into it, you're like, oh, but there's
you know, of course, you know, anybody could be wrong
about anything, but there's actually there's pretty good evidence of

(07:45):
it being a very robust concept. For me, I feel
like I had this kind of vague idea about dark
matter and not that I have like a deep, like
mathematical sense of it now, but I have a much
better picture on like why we need this and what's
neat is that does kind of proceed out cause it
proceeds out like in this kind of fairly neat historical fashion,
where like each each discovery kind of leads to a
whole new set of problems, and so like for me,

(08:08):
at least chronologically, you're telling the story of the things
that we're thought in different time. Gives you a much
better sense of where we are now and how we
you know, how we got there.

Speaker 1 (08:17):
Yeah, it's sort of like a meta story. I mean,
I think of each kind of science as a story.
We're telling a story about the universe. Here's how it works.
It does this, it swishes that way, it expands the
other way, and now we're telling like the meta story
of how that story has evolved. And I think that's
really cool, and especially for this topic, you know, the
whole universe, the cosmology. This really is fascinating to go

(08:37):
deep into history because it's an ancient question, right, Like
literally the question that people asked thirty five thousand years
ago or maybe even one hundred thousand years ago as
they're looking me up into the night sky are the
same questions we're asking, like what's out there? And how
does that all work? And what does that mean for
how we're going to live our lives? And whether or
not I should bank that person on the head with
a rock to get their stuff right. Basic questions with

(09:00):
trying to figure out the answer to you.

Speaker 2 (09:01):
Yeah, yeah, I mean, you know what's cool about that too,
is you know I had this. This is something that
I felt very strongly when we were researching the history
of space travel, which is like, it's amazing the cadence
once you get to the twentieth century, like that, that
to me was one of the most astonishing things because
you know, it's like you go from this world where
it's not clear that even like like nebulae or galaxies,

(09:23):
and then suddenly the universe is gigantic. So it's amazing
that a person like if you talk to a farmer
in like eighteen hundred, you know they certainly know more
than like a farmer from like three thousand BC. But
there's sort of universe. Isn't that much different, you know,
in terms of its scope? And then all of a sudden,
like very quickly, it's not only gigantic but kind of alien,
kind of like bizarre. That for me was astonishing, like

(09:45):
like just during like a thirty year period, how much
how much like it must have been a very strange
time to be an astronomer.

Speaker 1 (09:51):
It's a strange time to be a human because each
of these discoveries changes essentially the universe that we think
we live in, which changes the context of our whole lives.
You know, we're important and we're in the center of
the universe. Nope, we're a tiny speck of dust in
a vast universe. Right, So go ahead, bonk that guy
with a rock. Nothing really matters, you know, but let's
take it one step at a time, let's go all

(10:13):
the way back. I love that in your book you
really started from the very basics of cosmology, which really
has its roots in like mythology. You know, before we
had like sensible ways to develop knowledge, people just told
stories about what they saw in the sky. Tell us
a little bit about that how far back did you
do your research? Did you learn to read like ancient
clay tablets?

Speaker 2 (10:34):
I wish, I wish I had the kind of time
to do that. No, I got like books of creation
myths and selected a few that like seemed to lend
themselves to making jokes. The joke for me was like,
you know what, what we always do, of course, and
so the deal in science is you have a theory
and then you assess how it interfaces with the fact.

(10:54):
So the fun part was to kind of be like,
how would you rule out this theory from ancient Babylon
using modern cosmology, which is kind of fun. Like there's
a joke about how like in the innumatt Elish, there's
this idea the goddess Tiamat was split in half and
half of us stretched into the heavens, and that that
is the heavens.

Speaker 1 (11:11):
You know, backup, tell us what this document is. You
referenced it, but it's not something I'm familiar with.

Speaker 2 (11:15):
Holy documents from the ancient Near East, you know, where
were the cradle of civilization?

Speaker 3 (11:20):
Can I say, by the way, what's what's kind of
it's kind of fascinating to me anyway, Like like why
do humans bother with stories like this?

Speaker 2 (11:26):
You know what I mean? So there's stories like that
you read in like religious or like you know, oral
history traditions that do seem to really clearly have like
a political or social organizational purpose. And maybe in some
of these cases with these foundation myths, what's going on
as they're saying like we're a special group or something.
But a lot of them just seem weird, you know,
like do you know what I mean? Just like there's

(11:47):
the other one I mentioned, well, the three I mentioned
is this one from ancient Babylon or ancient Near East,
and one from ancient China, although China is very old,
so it's kind of like the middle of China. And
then like like of course one about the Bible and
what's fastly like the one in China is just about
like this is this story about a giant who just
sort of carves up the universe. Still there's like still
there's a sky and the ground, and then he dies.

(12:08):
And then a theme that I think is in a
number of other creation myths, parts of like this initial
being become the pieces of the universe, and so there's
there's at least not a kind of obvious, and therefore
here's how you should live your life, or and therefore
the guy with the tall hat is in charge, you know.
And so it's just kind of fascy that we like.
But every culture does this, every culture. I mean, maybe

(12:28):
there's some exception somewhere, but it seems to be a
normal thing to just speculate on how things started. And
I don't have like a sort of good theory about
why we do this.

Speaker 1 (12:37):
Yeah, I think it tells us something about why these
questions are important. But I think cosmology as mythology sort
of tells us about the way we do science. Also,
I think in the end, it's all stories. Like the
scientific answers we have now are still stories. I mean,
they're supported with evidence and they're backed by mathematics, and
they're told in a different language, but still their stories.
And I don't know, I think maybe it tells us

(12:58):
just about the way we think as like rational creatures
looking for cause and effect, you know, as a human
being living in the world, you're trying to understand, like
I was hungry today, Why I wasn't hungry? Oh I
didn't eat Okay, there's a story, you know, It's just
sort of like maybe part of the way our brains
work and the reason that we use cause and effect
is a way to explain the whole universe, you know,

(13:19):
just that we are storytellers. But it's fascinating also to
me what those various stories tell us about the people
and the sort of the tools they have to tell
those stories. Like we know that the ancient Greeks told
a story about the structure of the cosmos, and their
story was like very geometric, right, They had euclid, They
had geometry like build deeply into their brains, and so
they thought about, you know, the Earth is the center

(13:40):
of the cosmos and things are moving around them and
everything is embedded in spheres. But if I read like
ancient Chinese texts about this, you know, the Chinese didn't
have the same sort of advanced sense of geometry, but
they were still studying the stars. They like looked at
the stars and they used you know, algebra and like
arithmetic to study these patterns. They just didn't think about
it in the same sort of geometric way, which is

(14:01):
sort of blows my mind.

Speaker 2 (14:02):
Yeah, that's interesting. I have thought about that way. But
of course, you know, a lot of ancient Greek traditions
have that like you better know your geometry because it's
a it's it's important to philosophy. Yeah. Yeah, it was
Plato's academy who had a sign that said something along
the lines of like, you know, don't enter here unless
you know. I think it was geometry. I might have
that wrong. Yeah, that's what I hadn't thought of it

(14:23):
that way. Yeah, Like they come up with this, like
you know, neat spherical universe, and then you know, like
like thousands of years later, people are still talking about
platonic solids and the sort of thing as aspects of
the universe.

Speaker 1 (14:34):
It's interesting. I was reading an analysis of ancient Chinese
cosmology actually, and they were talking about how it's sort
of weird that the Chinese never really applied geometry to
their system. Like the Chinese picture of the cosmos is
like a flat disc of an Earth surrounded by like
a half bowl of a sky, and this sort of
makes sense to them in terms of their equations. They
can like predict eclipses and stuff, but doesn't sort of

(14:54):
like come together in your mind, like if the sun
goes below the earth disc, then like everything in the
sky should be shaded. Then why is like the moon
ever bright? You know, it's just sort of like just
does it make sense from a very basic geometrical standpoint,
And there are some evidence in writing or people like
trying to put this together and be like, hm, just
doesn't make sense. I don't know, and they just sort

(15:15):
of move on.

Speaker 2 (15:16):
I wonder what some of this stuff what's going on?
Is like, it's very easy as a modern person to
be like, well, obviously the utility of this stuff is
just knowing how the universe works. But to a person
of a particular point in the past, it's the utility
is so I can do astrology or I can yeah,
you know, some of the things, it's not really relevant
if it's quite accurate in that particular sense.

Speaker 1 (15:34):
And of course, the Greeks famously got a bunch of
stuff wrong, right. Part of the story we're telling today
is how everybody got everything wrong for so long. And
so you tell this story in your book about why
the Greek settled on a cosmos with the Earth is
at the center rather than the Sun at the center,
and it's all about parallax. Do you want to tell
that story?

Speaker 2 (15:53):
Yeah, yeah, Well it's just it's funny. You know I
should say this is all like I don't want to
be able to get the impression that it's too in
depth in this book. It's a joke book. But so,
like you know, if you're just sitting here on the
surface of the earthing, you don't have a really good telescope.
The stars don't parallax, which makes perfect sense if the
Earth is just in the middle end immobile, and doesn't
make sense if the Earth is moving around the Sun.

(16:13):
But of course, you know, the truth is they do parallax.
It's just that they're so far away. We don't find
this out till I forget. Who's the first person observes that?
Would that be like eighteenth century? It's it's in the
book somewhere.

Speaker 1 (16:23):
Yeah, it's like almost the eighteenth century before we can
actually see the stars.

Speaker 2 (16:27):
Wiggling right, yeah, yeah, yeah. So it's like it's actually
quite reasonable, so to speak. It's like, why don't they
do this? So I do talk about how there is
a guy named Aristarchus of Samas who actually got pretty
close to the mark, though I think you always want
to be careful with this. I mean, I kind of
tell this as a joke because, like you know, it's
a little dangerous to be like, well, Democratus was right,
and it's like about Adams, you know, but you get

(16:47):
to be a little careful because it was like, well
it was he right for the right reasons, you know,
and or more to the point, it's like if everybody's
got a theory, you can always look back and be like, ah,
this one person got right, you know. But indeed there
was a guy named Aristarkus iss same Us who said,
you know, the sun's in the middle of the Earth,
goes around it, and even suggested the Earth was tilted
on its axis, which is pretty darn cool. But of

(17:08):
course that theory can't explain a bunch of stuff that
the Aristotle theory does explain, like like the star's parallax.
And then there are these, you know, other ideas about
like if Earth is zooming around, why don't I, like
you feel the normal effects I would feel if I
was like zooming around to us now as a mine field.
That's not very intuitive, but it would make perfect sense
right back then. I suppose that that, like why why
don't I feel the wind blowing on my face? Why
why woun't I drop something? Does it just goes straight

(17:29):
down if I'm like going around this racetrack. You know,
so there are actually good, good arguments for Aristotle's position
over against Aristarchus's. So, I mean, I do kind of
tell this as a joke, like why didn't we listen
to Aristarkis? But you know, of course it's a dangerous
thing to reason backwards from history and try to find
the one crazy guy who happened to be right.

Speaker 1 (17:47):
Exactly. You've got enough crazy Greeks with enough typewriters, and
one of them is going to bang out a theory
of the universe that looks pretty good in hindsight.

Speaker 2 (17:54):
That's right, yeah, exactly.

Speaker 1 (17:56):
But I love this argument of the Greeks. They're like, well,
if the Earth is moving, then we should be able
to tell, And you're right. They're more sophisticated than just
like I should feel the breeze or we should all
fall off the earth. They came up with a really
clever strategy to tell if the Earth was moving, like
let's look at the stars and see if they're wiggling.
And they were totally right. Their mistake though, was that

(18:18):
they thought the stars were close by. They thought the
stars were like not really that far away. And so
they should be wiggling a lot, and that was the
one mistake they made. If they had known the stars
were so distant, they might have figured this all out earlier.

Speaker 2 (18:30):
Right, And it makes sense because it's like stars are
really far away like distances, you know, like not that
we encountered distance like this in normal life. But it's
like a little less crazy for Ustna because we're just
used to it, right, but like insane, like impossible. I
thinking about how you would have to express these numbers
before you had Arabic numerals, So it's not surprising there
for them that was unintuitive.

Speaker 1 (18:51):
All right, So I can't wait to dig into more
ways that we got cosmology wrong. But first let's take
a quick break. Okay, we're back, and we're talking to

(19:11):
Zach Wienersmith, who's written a joke book about cosmology, making
fun of everybody else's clever ideas about the universe. Zach,
do you feel like that's your role in modern nerd
dumb is just to make fun of ideas?

Speaker 2 (19:25):
Uh? To the extent. That's a fun job. Yeah, I
like that job.

Speaker 1 (19:29):
That's you guys over there work really hard. I'm just
gonna sit here and make potshots at you.

Speaker 2 (19:36):
Oh no, absolutely, you know, look, this is all about me.
I'm just I'm just I'm just enjoying myself, especially making
fun of chemists. Chemists. It's just really, it's just really satisfying.

Speaker 1 (19:47):
Oh you gotta be careful. I made some comments about
chemistry on this podcast, and I got some emails.

Speaker 2 (19:52):
Let me tell you, Oh boy, then they're dangerous too.
They know how to blow stuff up.

Speaker 1 (20:02):
My son was taking high school chemistry last year and
he asked me for help and I couldn't help it.
And then I got frustrated. And I remember being frustrated
by high school chemistry and expressed my frustration on the
podcast towards the whole field of chemistry, which of course
for which I have nothing but very deep respect. I
was reminded of the reasons for that.

Speaker 2 (20:18):
Okay, well you know what. Here's the thing about chemistry.
I'll absorb the emails on this, which is that like
in biology, you're just like, okay, nothing makes any sense.
It's all specific every time you look at one thing.
And in physics you're like, oh it all, it all.
There's like two equations you just have to reply them.
But in chemistry, it's like it is this unholy hybrid
where there are almost rules. Did I ever tell you

(20:39):
I was? This is ages ago I was in I
were talking to a chemistry professor and she had this
story about they couldn't get enough tas, so they brought
in a physics TA figuring like, well, teach chemistry. And
I guess, like me, but you or I would have
done which is he was? The story I was told
was that he began with the shorting gear equation.

Speaker 1 (21:02):
In principle, you can derive all of chemistry from that.

Speaker 2 (21:05):
That's right, that's right. Just it's an exercise for the student.

Speaker 1 (21:11):
No, I get it. But you know, also modern science
has many, many different layers. We don't just do particle
physics for everything. Right, you can't get the price of
sneakers using string theory, you know, there are other useful
kinds of science right there for sure? All right, So,
but today we are talking about how cosmologists have always
gotten it all wrong. And we talked about how the

(21:33):
Greeks got it wrong, and the sort of ancient picture
of the Earth at the center of the universe was wrong.
But let's talk about how we figured that out and
sort of like the steps along the way, because I
think often that just sort of gets YadA YadA over
you know, Galileo telescopes. Therefore, we figured that out. But
there's a bunch of interesting steps and like different paths
people were taking at the time to get there.

Speaker 2 (21:55):
Yeah, for me, this was maybe the most interesting part
of the book. At least it didn't involved modern cosmology,
which was like, so you know, the story that I
think I was told was one you go to Claudias
Ptolemy and like everybody who does now outmude a science,
he's like treated as being kind of silly because he
has his epicycle model, which you just be clear, just
you know, it's it's it's it's Aristotle's you know, spheres

(22:17):
within spheres model, but with these little modifications to make
the planets behave, and it's is quite a good model,
and it rains for you know, over a thousand years.

Speaker 1 (22:27):
Right, and let's be clear, it really works, right, It
like actually matches what we see people laugh at, like oh,
cycle circles within circles, ha ha, but like this thing
really worked, It really works.

Speaker 2 (22:38):
Yeah. I always want to say that The funny thing is,
I mean there's stuff like this right now where we like,
so you know, famously relativity matters for like timekeeping on satellites.
But I could be wrong, but I assume the satellites
don't put in like relativity equations. They just tick back
one second or something, you know, like and it's a
perfectly good way to model the system. And it's likewise
with epicycles. The main problem with epicycles is I understan

(23:00):
and it is just that like, well, one, of course
they don't actually exist, that's a non trip, but like.

Speaker 1 (23:07):
That's a detail.

Speaker 2 (23:08):
But beyond that, it's also just like it's not very
satisfying as a kind of scientific theory to say, like
each planet has its own thing and that's just the deal.
That maybe it makes more sense in a world where
you're imagining like this is all like set up by
a deity who did it a certain way or something,
you know, and they just made the planets this way.
But anyway, so and the next issue except this blew
my mind. I'm sure cosmologists all know this, but so

(23:29):
you know, the story that gets told is Copernicus writes
his famous book Dies in fifteen forty three. It gets published,
and it proves that the sun is in the middle
and you're all done. But the amazing thing is Copernicus
actually preserved epicycles for a different reason, which was that
he thought he was still kind of in this zone
of perfection, like the space still has to be perfect,

(23:50):
and so these objects in space move in perfect circles.
They go around the sum, but in perfect circles, and
that creates problems because you don't get these funny little
behaviors of the planets. They're not moving in ellipses, and
so that just totally blew my mind because you know,
I think we'll make a version of this over and over,
which is that like I was talking to call you
about this the other day. It's like you hear these

(24:11):
stories when you're a student that there was a decisive
experiment or thought that just changed things instantly, and it
turns out there's a lot more vibes to it, and
old theories die hard because like the old theory wouldn't
have been there in the first place if it wasn't
pretty good. So that was fascinating to me. And then
the next thing along those lines, which which blew my
mind again was was you get to Ticobrahe and I

(24:33):
had thought he had just another Sun centered model, but
he didn't he actually had the Earth at the center.
What he did instead, And this is the kind of
thing where I think I would ask your audience to
sort of close their eyes and visualize this, because it
takes a second if you don't like have a picture
in front of you, which is what he thought. What
ticobrahe thought, is there's Earth in the middle, and then
if you can imagine it far out, you got the

(24:53):
Sun going around the Earth, and then around the Sun
are the other space objects, the other planets, which is
kind of amazing.

Speaker 1 (25:01):
It's genius. Is genius when like, let's keep the Earth
at the center while solving the problems of the data.

Speaker 2 (25:07):
That's what I love it. And you can almost if
you want to be sort of generous, you could kind
of think about it as sort of trying to bring
together these two ideas, one of which is like, what
is the data telling us? And one of which is
like this idea we want to hold on to of
a kind of like Earth centered cosmos. And I think
you can argue there are tensions. You know, you don't
want to stretch the analogy too ver. You can talk
about there's certain tensions in modern cosmology, Like you know,

(25:30):
my understanding is the reason and I won't get too
far ahead of this, but like there's a question about
like why is there more matter than antimatter? And part
of why that's even a question is just like, well,
I do think you could argue that part of why
it's a question is that physicists kind of like balance,
or at least they'd like there to be an explanation
for why there isn't a balance between things. And what's
interesting is it's not quite the same as saying there
should be perfect spheres or you know that there should

(25:52):
be in the center. But there are kind of vibes
about these things about like what what is attractive to us.
But what's also funny though, is that bra Hey like
by trying to kind of you know, do both sides,
ends up creating this kind of unholy hybrid that's just
just just not on.

Speaker 1 (26:08):
I think it was more of a holy hybrid, right,
he wanted to at the center, right.

Speaker 2 (26:13):
Yeah, So that was amazing to me. And then and
that ties into like the thing I think it really
was interesting to me That gets into how we tell
these stories, which is so there's a story that iray
are being told to me. And then I looked it
up and I found it in other places, so it's
not just me misremembering, which is that it goes something
like this is Galileo points his telescope at the sky,
which of course he actually did, uh, and he sees

(26:35):
that Venus has phases and that tells him that Venus
must go around the sun. And I had actually written
this into the book. Maybe it was one of the
drafts reat I remember I was rereading it and I was like,
it struck me. I was like, wait a minute, Like
I can think of other ways Vias could have phases,
at least in the narrow sense of like part of
its light and part of it's dark, and this happens
in a cyclical pattern, and in fact, like that's not

(26:55):
even precluded by the Ptolemy model. It's just you know,
because because you know, even if like the sun is
just like the third object out, it's going to be
in a different relation to us visa v Venus on
a repeating basis, so there should be something like phases.
And so my understanding, I got way too into this
before I had to like give up and then get
back to Uh, just like writing the one sentence I needed.

(27:18):
But it's like, it's not the venus has phases, although
that's part of it has phases, and also the phases
coincide with it, like getting bigger and smaller in our
field of view in a certain way that is very
hard to salvage in a ptolemy model maybe possible, I
don't know, but which makes perfect sense if you put
the sun in the middle.

Speaker 1 (27:35):
Yeah, and I love how this reveals how much work
is involved in making jokes about science. You know, as
a fellow like jokey science book author, You're right, you
had to really know your stuff to make a joke,
and you could end up reading like a whole book
to support one sentence.

Speaker 2 (27:49):
I no, No, it's totally like that. Yeah. I think
what it is is, in order to tell a joke,
you have to be like a little bit of a snot,
you know, and you can't do that convincing landless. I mean,
I don't want to treat like I'm like a deep
expert in cosmology, but but my view, I was talking
to Ron Aberminsky as a sociologists about this, who also
writes pop science, and he says, you know, it's almost
verbatim the way I like to say, which was that

(28:10):
you like to at least be like two steps ahead
of what you're saying. You always know a little bit
more than what you're saying. Then you feel comfortable saying it.
When you're not there, you start to feel a little
like you're not at leisure to make this joke because
your joke might reveal you as an idiot, and so
that you know, that's why you end up like reading
with this. I mean, you know it's a popside thing.
I'm sure I blew it on something, but like I

(28:32):
you know, I did a like you look at these
diagrams and you're like, I must be misvisualizing this, Like
why can't Venus have phases? And by the way, in
the Brahe model, you can really get those phases right
because it really is going around the sun, you know.

Speaker 1 (28:45):
Yeah, So just to clarify for our listeners in case
they don't have this picture in their mind, you know,
what we're talking about is like how much of Venus
you can see, how much is illuminated by the sun.
And it's very easy to imagine in a sun centered
solar system that as Venus moves around the Sun either
all of it is lit up. Like, if Venus is
on the other side of the Sun than the Earth,

(29:05):
then all of Venus that we can see is lit up.
And if Venus is on the same side as the
Sun as Us, then the side of Venus is lit up,
it is pointing away from us, and we're only seeing
Venus is like dark backside. So in this sun centered system, right,
you see like huge phases of Venus the same way
you do of the Moon. But in the Ptolemaic system, right,
if Venus is going around the Earth and the Sun

(29:28):
is also going around the Earth, then you're absolutely right,
there are still phases there. They're not the same kind
of phases and they have different patterns than the phases
in like our system, but you do still see phases.
So the simple story that people often tell that like
phases of Venus proves that the Sun is at the center,
You're right, it's not accurate. You can have phases and
actually have the Earth at the center of the system.

Speaker 2 (29:50):
It's fascinating, it's totally fascinating. And related to that, what's
right that was amazing to me is the story about
part of another thing. Is he just looks at the moon,
and of course, you know, anyone who's looked at the
moon with a telescope, even a crimey one, even in binoculars,
you can see that there's lumps on it. You know,
there's there's peaks and valleys and stuff. And what's interesting

(30:10):
is to a modern person it's kind of like, well,
I don't it's hard to imagine why that matters at
all to any of the pictures of about like where
things are. But Mind's saying is that was very important
because it's like, if you're existing in this paradigm where
these are sort of the divine sphears and then you see,
oh my god, it's got lumps on it, just like
the home planet, you know that that was actually a
big shift. But what's interesting about that is that, you know,

(30:31):
and I'm sure I'm being unfair to this complex history,
but it seems like like there's some deep level on
which what's going on is like kind of vibes based, right,
and especially me when I say it's like there's this
never definitive experiment. It's actually like three or four things
where you're like, you know, we could salvage the old model,
but the amount of stuff you'd have to say just
happen to go right is getting bigger and bigger, and

(30:52):
whereas if we switch to this you know Kepler model
with these nice little laws and the sound of the middle,
like the math is very simple and we don't have
to do anything that feels ad hoc or at least
I guess not too much, but that it explains to
you also why this stuff is such a process, and
how like you know, the simple story won't do because
actually the work is quite meticulous. I feel like it's

(31:14):
very easy as a modern person just sort of be like,
you know, well just like run the video back of
like how you know how Venus looks in the sky,
but you can't do that. You cannot even take a photograph,
of course. It's just astonishing the people were even able
to work this out to me, like just kind of
like you you imagine Kepler just kind of like looking
at tables and somehow these ideas are and instead it's
it's incredible.

Speaker 1 (31:33):
It tells you why geometry was so powerful, right, Like
it helps you import into your mind this sort of
three D picture of what's happening, rather than just like
looking at lists of numbers, which is really hard to visualize,
and to me, the answer to the question of like
what's out there, the answer to that is a geometrical answer.
It's this is here and that's there, and this is
the relationship between them. But I think partially that's just

(31:56):
because we're all, you know, thinking the Greek way, and
if you know, the Chinese cosmology had taken over the planet,
we might all think about things more arithmetically and more algebraically.
It's hard to imagine. I think like the way the
Greeks thought has influenced the way everybody thinks so deeply
that it's hard to really step out of that and
think about things in a different way.

Speaker 2 (32:15):
Yeah, that's interesting. It's just two to me, like because
Colon X, we have to get to Newton, which is
like there's this repeated figure. I think it's science that
it's the Newton figure. Who's the person who comes along
and you're trying to told this story that as if
they sort of like called the lightning down with the
theory fully formed, but actually like perhaps be more accurate
to say, like there's a lot of information already. And
they were the ones who said, here's the grand synthesis

(32:36):
and so that's passing to me because like, I, you know,
just just just reading about Newton, who who I think,
you know, there's at least the stories that get told
about him, I would say more accurate. At least that's
my impression. But coming along and like, part of why
Newton's theory is so powerful is you have a kind
of like simple theory about like you know, how like
a baseball. Well, he wouldn't have a baseball, but like
how a rock behaves in your hand, and you can

(32:56):
use like the same math and it just pops out
all this stuff, including Kepler stuff, which is just you know,
so amazing. And by the way, my favorite detail about
that too is this story that like that like I
was telling this my daughter and you just got a
fit of the giggles of like Newton having basically worked
out how the universe works and being like I'm just
gonna sit on that, like it. It's so different from

(33:22):
modern science. I don't know, maybe there's someone like that
monitor So there's probably someone out there is like the
modern Newton who just like unified everything a couple of
years ago, and it's just waiting for Edmund Halley, the
equivalent to be like, you know that just that really
feels publishable to me.

Speaker 1 (33:34):
It's hard to imagine, especially at Cambridge, you know, which
I think has basically been a shark tank for centuries. Right,
I don't understand that, right, you didn't get on that.
It is fascinating, But I liked your point earlier about
how old theories die hard, and that a lot of
what we do in science is vibes based. And we'll
get into it later, but there's a lot of just
sort of like preference for different kinds of theories about

(33:55):
the universe. You know, we have this thing we call
like the cosmological principle the universe should be the same everywhere,
and like why do we think that, Well, because it
would be pretty cool if it was true, and we
haven't proven it wrong, so let's hang on to it
as long as we can, right, Yeah.

Speaker 2 (34:11):
I was talking a little Sean Carol about this, about
this idea that like, you know, there's this debate we'll
get to it in a minute, about like which shape
is the universe, But he was pointing out like, well,
you know, you could just ditch the cosmological principle and
then all sorts of things open up, and it's like,
but we don't want to do that, and we'll get
to that. I guess we should stay on track.

Speaker 1 (34:29):
All right, so let's take another break before we come
back and consider ditching some fundamental ideas in modern cosmology.

(34:50):
All right, we're back, and we're talking to Zach Wiersmith
about why ancient scientists have gotten it wrong and why
modern scientists are probably also going to be made fun
of in future joke books about the universe.

Speaker 2 (35:00):
Yeah, so we're up to Newton. And then, of course,
you know, Newton like reigns supreme at least over cosmology
for a long time. So my understanding is Newton we
could say he solved the universe, and of course he
you know, he has the equations for gravity at least
in the in the relevant regimes. But my understanding is
he believed the rest of the universe was like infinite
with like randomly distributed stars, so as we would say

(35:20):
it today. And so this creates problems, right, So the
famous one is Olver's paradox, which is this, if there's
all these stars in the universe has been around forever,
how come I can't find my keys when I go
outside at night? Because it's dark. Shouldn't there be light everywhere?
And there's all this other stuff like, you know, people
this time can see nebulae, but they don't really know
what they are, you know, and they you know, can see,
you know what we come eventually to know our galaxy

(35:42):
is just like ours, but they don't know what they are.
And this to me is like this incredible period of history.
When we're talking about the nineteenth century, we're not talking
about that long ago, right, Like we're talking about like
two grandma's ago, right, like really not that long ago.

Speaker 1 (35:54):
What a unit of time, that's.

Speaker 2 (35:58):
Right, Yeah, speak people from that time lived in a
much smaller universe in their perception, And I guess you
would you would say the big figure in working this
out is Henrietta Swan Levitt, who figures out a way
to like objectively measure the distance of certain objects in
space and help settle this idea that in fact, yeah,
those stars are really really really really far away, and
then that leads to you know, all sorts of cool,

(36:20):
cool analysis. There's actually I think I don't even know
I had this in the draft, I say you, but
I edited this version. So there's a story I was
telling that I think is slightly wrong, which is that
Hubble looks up and sees red shifting and then concludes
the universes expanding. But it's actually a little more complicated.
I mean, you know, again like this is a joke book.
I don't get too into it. But there's this guy
named has the best name ever. It sounds like an

(36:42):
alias Vesto Melvin Slipher if I'm pronouncing it right. My
understanding is he is an American astronomer. He is the
first to say to note the red shift, although I
believe he was first using it to say that, like
the galaxies are spinning, but he notes this red shift,
and he starts like looking at galaxies and there's this
weird thing which is not all but most of the

(37:04):
galaxies are red shifting. But just the important thing is
that the galaxies are mostly moving away, which is, you know,
you would you would think naively that it should be random, right,
There's just a bunch of stuff floating around in space,
and it's just kind of random. And the story I
think I was told, in the story I was I
was planning to tell, was just like, well, Hubble comes along,
says red shifting, and therefore the universe expanding, right, because

(37:26):
that explains what everything's moving away from us. But what
actually happens is Hubble says, so red shifting is already
very well known by the time Hubble is making this
big contribution, which is this equation that says the distance
of the galaxy is proportional to its velocity. That is,
the farther away the galaxy is the faster it's running
away from us, which is super duper weird, right. I

(37:46):
mean this I think about this too, is like, so
it's not just that during this period the universe got
a lot bigger, it's they also got a lot weirder, right,
I mean I feel like, like all these cosmologies we've
talked about so far, like you could explain to one
pretty easily. You can draw a picture and be like
it's like this, you know, and people basically get it.
But then you say everything in space is moving away

(38:08):
from us at the same time, almost everything. That's bizarre,
and especially if, of course you don't want to conclude
and now we know better why, but you don't want
to conclude that it's because we're special, because that's proven
to be historically dangerous. But that's very unintuitive, right, and
then it's more inintuitive, like why should farther away stuff
be expanding away? And it turns out there's there's a

(38:28):
very clear explanation. But that like is getting into this
part of history where cosmology just is not something that's
intuitive to people anymore, which is that space itself is
a stuff that's expanding, and so there's just more of
the stuff between us in a distant galaxy than a
close one. You know. The classic metaphor, which tell me
if you don't like the classic metaphor is the raisin

(38:49):
bred one. You know this one?

Speaker 1 (38:50):
I love that metaphor. Yeah, that one works really well.

Speaker 2 (38:52):
Yeah, I think it's a nice one. I mean, you know,
the way where it breaks down to me is like
when you're trying to get the big bang out of it,
you're like, I guess that the raisins are getting close
to each other until you have some sort of ultra
deaths raisiny something, you know, and like the bread has
gone away or I don't.

Speaker 1 (39:05):
Know, it changes phase into a raisin plasma.

Speaker 2 (39:09):
It's right, this is a paper. This is a paper.
But we'll get to that in a second. But yeah,
like what I love about the razin bread example, is
just like, so the idea is that you know, I
guess raisins would be sunding like the galaxies, and the
bread dough is space. And when you bake the raisin bread,
it's not just that the raisins pull apart from each other.
It's that the ones that are initially apart from each

(39:29):
other get farther faster because the dough is expanding and
there's just more dough in there to expand. And that's
where it gets really neat and even more attitude because
you're like, this is Einstein's general relativity, that space time.
You know, space is not the stage where stuff happens.
Space is the stuff. Space time is the stuff. It's
the raisin bread. And to me that it's just such
a fascinating little amment. All this happens in like a

(39:51):
twenty year period. It's just absolutely incredible. It's like unfathomable
to me, like in this era where like all sorts
of cool results come out all the time now, but
it's not like that, it's not like the holy universe.

Speaker 3 (40:00):
Your conception is blown away and again makes this kind
of phase shift, so to speak, from like you know,
vast but intuitive to hard to understand, at least for
most of us.

Speaker 2 (40:12):
You've been around general activity so long, maybe it makes
perfect sense to you all the time, but for the
rest of us, it's like, we got to think about it.

Speaker 1 (40:19):
No, it definitely doesn't. And I think you're right that
we transitioned from a universe that like kind of we
could tell a story about to universe where people are like, hmm,
that sounds really math he it doesn't mean it makes
sense to me without a lot of math. I think
that's really fascinating. And it's also a really interesting story
there about like how even Einstein came to reconcile the
universe the structure he had built this general relativity with

(40:41):
what he was seeing. Because he was missing part of
the piece, right, he wasn't really able to tell the
story in the right way, you know, to sort of
connect the dots. When Einstein was developing his theory of
general relativity, people thought the universe was static, right, People
thought the universe was a certain way and it was
the most natural idea was it had always been that way, right,
that there was no beginning to time at all, because

(41:02):
that would be weird. You'd have to explain it. That
was like the vibe at the time. So then Einstein's like, well,
in my theory of general relativity, if we have a
static universe with a bunch of like galaxies out there,
they should get pulled towards each other. There's like gravity
pulling stuff towards each other. Why isn't the universe collapsing?
So he added this fudge factor right to like balance
up against that, which, if you look at it is
like kind of a terrible theory, Like it's really pretty

(41:24):
ugly because it requires this like cosmological constant to push
out on the universe in exactly the same amount that
everything's pulling in. It's like super finely balanced, which these
days people would have rejected that paper. They're like, that
is a terrible idea. You have this huge coincidence in
your universe. So then Hubble's like, well, actually the universe

(41:44):
is expanding, right, And so then we're like, hm, well
that's interesting, you know, why would he be expanding that much?
And so Einstein's look, well, maybe it's expanding, but it's decelerating.
Maybe everything is still collapsing, but it's still expanding. It's
like expanding now, but expanding slower and slow or due
to that gravity, right, So Einstein still didn't really have
a grip on what was happening, and it took a

(42:06):
while before you know, we discovered the universes expanding and accelerating.
They had to like reinject this Einstein cosmological constant to
explain what we were seeing. So you're right, And I
think that the current explanations of this stuff have led
a lot of people to really pretty deep misunderstandings of
how this stuff all works. You know. I want to
talk about sort of like the misconceptions of modern pop cosmology,

(42:29):
because I think you ran into some of these when
in writing your book, and I think like one of
the big ones is this idea of the raisin bread
like and the origin of the universe. I think a
lot of people have in their minds this concept that
the Big Bang was like a tiny dot, the universe
was an atom, and then it exploded through space and
filled everything out. I hear that all over the place,

(42:50):
people ask me, like, where was that dot? Where was
the center of the universe? Can we see it?

Speaker 2 (42:54):
Right?

Speaker 1 (42:55):
It's like a really common misconception. You must have run
across this also in your.

Speaker 2 (42:59):
Research yeah, I mean, like I'm sure I was guilty
of that. I had to update my understanding, and I
was trying to I was actually talking to Eugene Limb
about this, which is like, as you say, there's this
idea that the universe starts infinitely small as like whatever
that even means, right, and that's something else we should
gonna do. Is this idea of infinitely this or that
as being a real thing? But like, yeah, I was

(43:20):
trying to figure where does this idea come from? So
going through this from a chronological perspective, which I like,
this kind of what we said so far with Hubble
and Einstein te's up why you think there might be
something called a big what we now call a big bang, right,
Because if you have this universe that's expanding and it's
a like glob of space time, as I say in
my vastly oversimplified way, well, if you rewind the tape,
then you get to an earlier state where it's like

(43:42):
everything is very tight, right, or comparatively tight. It's kind
of intuitive to maybe say, well, like in the extreme,
it gets to a single point. But my understanding is Lemaitre,
who's the guy who's who's fame for proposing this didn't
believe that himself. He used the term primeval atom. But
my understanding is he meant at him is something like
fund metal, not as the size of an atom, And

(44:04):
so I don't know that's where it comes from. There's
probably some historiography out there of like how this idea
seemed into the public consciousness, But yeah, I found almost
everybody thinks big Bang means there was this tiny atom,
and the word singularity gets used, I think, to mean
infinitely tiny or something.

Speaker 1 (44:20):
Also because we use singularity to mean infinitely tiny when
we talk about like a black hole, right, we say
there's a singularity the center infinite density, a lot of
stuff trapped up in one point in space. And we
can talk about a singularity for the Big Bang. It's
just that it's a singularity sort of in time rather
than in space, rather than having all the seven universe
in one location. We have a moment in the universe

(44:42):
where everything was super duper crazy dense, right, And that's
the singularity we're talking about, which is similar mathematically but
conceptually sort of very very different because you're talking about
the whole universe. And I remember the first moment I
understood this, it was like a big bang going off
in my brain because what it means is the big
bang was not somewhere, was everywhere everywhere. Yeah, much bigger

(45:03):
bang than anybody ever thought of.

Speaker 2 (45:06):
Is it's not so much weirder, right, Uh, Like I
don't know. I mean, maybe it's again we're getting back
to the vibes. But to me, it's somehow like more
intuitive that you started this tiny point where something happened
and then it all expands out. But the idea that like, no,
it happened everywhere at the same time. I don't know
what to do with that, Like, my brain just doesn't
work on that.

Speaker 1 (45:23):
On other hand, it sort of makes more sense than
having one place be special, Right. Wouldn't it be weird
if the big bang was here and not there, because
then you could ask, like, well, why was it here?
What's different about this point in space? And there you go.
You break the cosmological principle that says everything is the same.

Speaker 2 (45:38):
Right. Yeah, but maybe this will get us to the
sort of the whole steady state stuff is there is
this weird thing where it just seems to be that
for some people, the idea of an eternal universe is
just more sensible than the idea of a starting point universe.
And I don't personally have a good feel for why one,
like do you have it like do you have a
gut reaction like like exeparate from what you know is
true or think to be true? Like what like do

(45:59):
you have a gut reaction about what is more satisfying
to me?

Speaker 1 (46:01):
The universe with no beginning is more satisfying because it
doesn't have a special moment in time, just like I
don't like a special point in space. A special moment
in time needs an explanation, whereas an eternal universe much
it just kind of always was.

Speaker 2 (46:14):
You see the probat is I this is just like
being a weird human. But you're just like my instant
thought is like, well what started at this eternal universe?
And you're like, oh no, wait, I can't ask that
you know.

Speaker 1 (46:24):
Exactly. It's like defining their grounds of debates, so your
question is no longer valid.

Speaker 2 (46:30):
This is why I really like going chronologically because you
now understand, like we even had like start talking about
the Big Bang because it follows very natural, like once
you have Einstein and Hubble, it makes sense to have
this this next idea, and then once you have this
next idea, you can start asking questions about like what
the universe was like. And so there's this big debate,
of course in the mid twentieth century, which is, well,
do we have a big bang cosmology or is it

(46:52):
this this eternal model called the steady state model, which
and then then the sort of avatar of this movement,
the famous person, and it is Fred Hoyle. You know,
so he has this idea you have this eternal universe,
and he has this thing called the creation field, which
is constantly adding matter to keep things in balance, they
you know, to maintain density throughout the universe. Right, then
you get this question like, well, you know, but both
these theories could explain this expanding universe we have. It's

(47:15):
just working in a different way. And this is where
it gets in issuing, because you're back to having these
two models that really say something very different. You know.
It's like it's funny because you can you can sort
of like finish newt and be like, okay, we basically
got it with Einstein. But there's actually this giant question
which is eternal versus not eternal, which is like massive,
So for me, like I will admit, like I'm a nerd.

(47:35):
I knew about like a lot of this stuff, but
I hadn't sort of worked out how all the pieces
fit together. And you're back to one of these like
at least to some degree, you know, vibes plus data
situations where you have its alpha and gammau and beta
gets slipped in for a joke. You know this idea
that like, well, if we assume the Big Bang model
is true, that is a you know, not that there

(47:55):
was a tiny point, that there was just a very hot,
dense beginning. Then we know stuff about how particles worganismsuf
about how matter it works, and we can say, well,
what you would you expect the universe to be like
later if it started like this? And it turns out
you can you can make predictions about kind of like
like roughly what elemental makeup should you see? And they
come up with these ratios and it turns out they're

(48:18):
they're pretty good ratios. And what was interesting for me
is something like that you're like, okay, but that doesn't
disprove steady state, right, but it at least says like
steady state requires more special pleading now, right, Because it
requires you to say the creation field that the oil
is positing happens to create with the same signature you
would expect from the bang model, which is because again

(48:39):
we're back to the like, well, you're you're you're comparing
two models. You know, the other model can basically do
whatever you want it to do. It just you know,
requires ever more special pleading. And that's what for me.
So I'd known about the cosmic microwative background, I think
I hadn't understood more deeply why it mattered, and so
I had to talk to a lot of people, including you.
And then the way I understand it now and correct
me if I'm wrong, is, or at least the way

(49:00):
the story I tell is that you know, you have
this background level of radiation, and it just the background
level of radiation has certain qualities that are exactly what
you predict under a big bang model. And so essentially
what you're saying is, of course, you know the steady
state model, where stuff is constantly being created, it could
be creating radiation too, and there's no reason that you
know couldn't create it just the right temperature and everything

(49:23):
and and just the right spectrum. But now you're to
be the steady state guy, you have to say, like, well,
I can handle all of the Big Bang results by
just saying that's how my system does it. You know,
I didn't predict any of it, but it's just how
my system does it too, which is a really hard
line to toe in science, you know.

Speaker 1 (49:41):
It is, especially because the Big Bang model predicts the
cosmic background radiation, which is really powerful.

Speaker 2 (49:48):
Yeah, so both sides can make predictions. It just turns
out that the prediction is like, you know, require you
you know, like like confirm one model and the other model.
You know, like ptolemy could could be made to accommodation
all sorts of things, but would require you to make
a Rube gold brig machine, you know, of like special
stuff that happens for no reason, which to me is
just sort of fascinating because you know, a story will

(50:10):
be told that's just something like discussing microwave background. Therefore
the Big Bang is true. And I feel like I
had heard this and repeated it and didn't have this
deeper sense of like, well, it's about like what model
can better predict this? This thing we find when we
look around.

Speaker 1 (50:22):
It's also really interesting what we mean by the Big
Bang is true. And it turns out that what you
mean by the Big Bang depends on if you're like
an educated person out there reading pop sigh about the
origins of the universe, or if you're like a researcher
and modeling this stuff, because there is a big difference.
A lot of people, when I say the Big Bang,
they're thinking about that singularity. They're thinking about the moment

(50:44):
of creation of the universe, this first initial brilliant flash
of light. Right. But when modern physics talks about the
Big Bang, that's not what they're talking about at all.
They like, fast forward past that part. They say, well,
that part's a huge question mark. We don't know how
anything got started. We don't know if there was a singularity,
if there's quantum gravity, you don't know if there's an
infloton field. It just basically shrug and they say, but

(51:05):
somehow we got to a very hot and dense universe.
Not infinitely dense, right, just some very very hot and dense,
like the hottest and densest universe that we could describe
with our theories. From that point forward, we know how
things work, and we can model things forward. We can
predict the cosmic microwave, background radiation, the structure of the universe,
and everything is like high precision science before that moment,

(51:27):
huge question mark. Now general relativity, you know, predicts a
singularity there, but nobody really believes that, right, No actual
physicist out there thinks that really happened in our universe.
They just think, well, we haven't figured that out yet.
So this is huge distinction between like what people imagine
the Big Bang is and what it is in like
actual science.

Speaker 2 (51:46):
Yeah. Yeah, So one of the really things related to that,
I'd love to hear your reaction to this is like
what seemed to me to be going on is a
scientist will say, we get an infinite quantity in this place.
But what they're they mean is that like the equations
we have with a theory we have here produces an infinity.
But that doesn't mean they believe there's an actual infinite
something or other. But I feel like it often gets

(52:08):
reported in the press as, oh, there was an infinity thing,
whatever that means, And so to speak, what the scientist
is saying is we have a problem, and what the
public is hearing is there were infinity.

Speaker 1 (52:20):
To me, it's like a segfault. Right, you run your
computer and the program crashes. You're not like, well, that's
what it predicted. It predicted the universe is going to crash.
It's like, no, your program didn't work. That's what it means. Yeah,
you've got a bug somewhere. Man.

Speaker 2 (52:33):
Yeah, it's really weird. I think part of what's going on.
I'm totally speculated here, but I think part of what's
going on is just because it's cosmology, and so you're
dealing with these things already giant and unintuitive, and so
I think if you're like a casual reporter who hasn't
gotten too much into it, you just you just hear
like it's infinitely dense, and you don't want to say, like,
according to an equation, which is probably missing something, it's

(52:54):
certainly missing something. There's an infinity here, you know, which
to me that was fascinating too, because there's just again,
there's this sort of between I mean, I think this
is a common thing. When you explore a field, the
thing that's being debated, it's almost always miles away from
what the public thinks the debate is.

Speaker 1 (53:08):
Yeah, and there are also these really fun moments in
science where physicists are like, well, the equations say this,
but that's ridiculous. It definitely doesn't happen. And then it
turns out it kind of does.

Speaker 2 (53:17):
That's a good one.

Speaker 1 (53:18):
Pot like black holes. People are like black holes. Nah,
there's no way the universe lets that happen. Okay, it
turns out and black holes are kind of a big deal.

Speaker 2 (53:26):
Yeah, that's that's an interesting point.

Speaker 1 (53:27):
Yeah, so basically, never listen to us. We don't know
what we're talking about, even when we're saying whether we
know what we're talking about.

Speaker 2 (53:34):
Yeah, yeah, you're right, right. So then that leads to
the part that for me was the hardest thing to write.
And so I'm going I'm going to lean on you
as I go through this to correct me if I
say anything wrong, because this is for me, the most
unintuitive thing, which is one of the big questions, is
the shape of the universe. And actually, for me, part
of what was tough is understanding why we even care

(53:56):
about the shape of the universe.

Speaker 1 (53:58):
Well, well, okay, so kind a visual person an economy
not worry about sheets.

Speaker 2 (54:03):
Come on, what I do perspective drawings. I don't wonder
about whether the unice is positively curved or not. You know,
I guess, I guess if the scale was big enough,
i'd have to mess with my lines. But no, But
it's like, I mean, obviously it's an aesthetically interesting question, right,
And there are lots of questions in cosmology where like,
obviously it's not going to make your car run faster
or put more food on the table. But it's just
like aesthetically attractive as a question, right. But so to speak,

(54:25):
that leaves open, like, you know, a huge number of
questions you could be asking, So why are some sort
of like more aesthetically interesting so well for your for
your audience. So this question is like the universe can
be curved in different ways that depend on how much
stuff is in the universe. And it took me a while, frankly,
to even get there with that. And I think I
actually think in retrospect, part of what was tough for
me about understanding this question, and you you helped talk
me through this as a couple other people, is this

(54:47):
Like often when people talk about this casually, what they
depict is something like the universe could be a big
flat sheet, it could be a the surface of the sphere. Yeah,
it could be a big flat sheet, could be the
surface of a sphere, or be a saddle. I'm positive
I've heard people say this and just sort of go
on as if like and just as an audience member
who is not a physicist, I mean, like I'm substantially

(55:08):
nerdier than the average pop science consumer, but like this
is deep math stuff and so like to me, I'm
just like, this just does nothing for me. I have
no idea what it would mean. And then worse of course,
as you help me understand, it's like, you know, we
can say fear, but actually we're really just saying positively curved.
And so it turns out there's like an infinity of shapes,
many of which are quite weird, that could be positively curved.

(55:30):
And that's actually true for all these models, like the
sheep can can loop back in on itself and do
all sorts of crazy stuff. Well I shouldn't say loop, see,
I gotta be careful with the words I use. But anyway,
like so, so these shapes that get presented to you
in a pop setting or I would say misleading, I
think they confused me because I started understand well, like,
why can't one to do the other and like, what
would it sort of feel like to be in one

(55:50):
of these universes? And I think that's just that's that's
just unintuitive, Like that's just that's too much for a human.
We're just little things. But as like why why why?
Why is this question interesting other than again the pure esthetics.
And that's where the history gets really interesting because it
turns out, you know, the spoiler that observations seem to
suggest we're in a flat universe. Flat flat again, like

(56:13):
being not the preferred term. I forget. We would say, like,
I know, you say positively curve of negatively curved. What
you say, I guess, I guess it's okay to say.

Speaker 1 (56:19):
Flat, Yeah, zero curvature and flat zero coverature.

Speaker 2 (56:21):
There we go, yeah yeah, yeah yeah. So we're in
this flat universe. And why that is interesting is that
it's surprising because it's sort of like you're balanced on
a needle point. Why aren't we often this one direction
of somewhere in positive curvature or somewhere in negative curvature.
We're in a flat sense. In other words, at least
as I understanding. It's an interesting question because the answer
is a weird one, and that's just that that's where

(56:43):
to me it gets fascinating. I mean, I'm sure like
like to especially to a cosmologists, the shape of the
universe is just a per se interesting question. But for me,
it was interesting to know this kind of like chronological
story about like it shouldn't be flat right like like
like it's kind of like the red shift, like it
shouldn't be mostly red shifts, Like something is wrong with
how I'm understanding the universe that I think it shouldn't

(57:04):
be flat. And then it becomes really cool, and that's
what really leads ever deeper in the confusing universe, which
it gets to inflation, which was perhaps the second most
confusing thing. It took me a really long time to
even kind of feel like I understand inflation, which maybe
if I if I have, I like done a good
enough job of basically saying what the point is.

Speaker 1 (57:22):
Yeah, I think so you've explained like why it's weird
that we have a flat universe. But to me, it's
not weird to wonder about the shape of the universe.
It's like wondering where it all came from. What is
the age in the universe. It's one of those basic
questions like if I was granted a visit to the
oracle and I can ask five questions about the universe,
like that would be on there, you know, I just
really I want to know our context, Like what is

(57:44):
this place? It's in the same category as like does
the Earth go around the sun? You know this basic
facts about the nature of our existence to me are important.

Speaker 2 (57:52):
Yeah, what it would be your number one?

Speaker 1 (57:55):
What would be my number one?

Speaker 2 (57:57):
You get five questions, you're like, your top.

Speaker 1 (58:03):
I think my first question would be does the universe
have a beginning? You know? And if so, what was it?
Because if there is a creation, then that creation tells
you a lot about like the context of our lives.
And if there wasn't, I'm like, wow, Yeah, I mean
I say that that's more of my preferred answer, But
I'll admit it's also kind of hard to digest an
eternal universe. That is pretty hard to fit into your

(58:23):
tiny little non eternal brain.

Speaker 2 (58:25):
Yeah, totally. Seven extent I wondered this, n like, why
why the shape question is interesting to you is because
it would sort the shape question would unleash a lot
of other answers. Is that is that sort of how
you think about that question? Like would be cool to
know the answer because of the sort of cascade of stuff,
or is it just like it would be cool to
know this thing because it's fundamental?

Speaker 1 (58:43):
To me, it burns that there are facts about the
universe that exists that are out there that we do
not know. So yeah, that really that really chaps my
hide that we just do not know. You know, there's
so much about the universe, these facts that just exist
out there that we don't know. You know, maybe aliens
have figured it all out and they know and they
would tell us and we just haven't even met them yet.
To me, that's endlessly frustrating.

Speaker 2 (59:04):
Yeah, I've been visualizing all the cosmologists like just walking
around angrily all the time.

Speaker 1 (59:11):
So what do people go with? They want to buy
the universe a Bridge Beyond Usefulness and also your new
book with Kelly.

Speaker 2 (59:17):
The Universe of Bridge Beyond the Usefulness is available on Kickstarter.
You'll just Google a search Kickstarter for it, so you
can buy it through the Kickstarter with a City on Mars,
but a City on Mars is also available for pre order.
I find bookstores everywhere if you do not wish to
order from one of the giant conglomerates. If you go
to a cityommrs dot com, then you can get other

(59:41):
options like Powells and indie books and cool stuff like that.
Or you can just go to your beloved local bookstore.
That's the best option of all awesome.

Speaker 1 (59:48):
Well, I recommend everybody out there get zach book on
the Universe, A Bridge, and also Zach and Kelly's book
A City on Mars. I've read both of them and
they're both a lot of fun and I learned a
lot before I let you have one more question for you,
Why do cartoonists want to write books about cosmology?

Speaker 2 (01:00:05):
That's a good question. I know. I'll give you a
theory that has no basis or I couldn't possibly substantiate it.
But like web cartoonists, early web cartoonists are like high
percentage dork quads, right, and so now now that all
of us are getting to the phase of our lives
where we have to do more things, we are all
like turning to our dork passions. That is my theory.

(01:00:28):
This is a surprisingly high number of physics dropouts in
the early cartooning community, so it was it was entirely
predictable from the late nineties that this would happen.

Speaker 1 (01:00:38):
Well, then, I'm really glad that the want to be
physicists inside all those cartoonists is getting to finally explore
that passion. Yes, all right, well, thanks very much Zach
for joining us today, and everybody go out there and
check out zach book and Zach and Kelly's new book,
A City on Mars. Thanks for listening, and remember that

(01:01:02):
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.