Daniel and Jorge Explain the UniverseDaniel talks to Zach Weinersmith about the most common misconceptions about our Universe.
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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. Hi, 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. 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, 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 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 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 for being married to Kelly, the famous guest host of this podcast. Zach, thanks very much for joining us today.
Thank you very much. Just to be clear, I'm more famous. You're just being funny, 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, economics, math, philosophy. Basically, Zach's job is to troll nerds everywhere. Together with Kelly, he's the author of Sunnish, a book that tells us why future technology will mostly be disappointing, and they have 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.
Oh yeah, yeah, Well we are the gatekeepers of the truth.
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?
The Weekly Wiener Smith released once every ten years.
Do you think it's a coincidence that twenty fourteen is the year you ended your podcast and also the year podcasts took off.
The coincidence is that my first child was born that year. 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.
The Universe Abridged beyond the point of Usefulness.
So why did you write this book, Zach? What inspired you to abridge the entire universe?
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 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. And strictly speaking, it's more like abridging cosmology and its history.
But I'm going with the universe.
What's the sort of special mental challenge that comes in abridging in like boiling something down to its essentials. Do you learn anything by a bridging the Bible and Shakespeare that you've applied to the universe?
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 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, people should just like do a fifteen minute joke set on it to actually prove they know what they're talking about.
So there were a bunch of places 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, 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.
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, and then later that's all thrown in the trash ban.
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 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 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 illuminated 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 can be wrong about anything, but there's actually there's pretty good evidence of 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 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.
Yeah, it's sort of like a metastory. 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 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. Basic questions. We're still trying to figure out the answer to you.
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, 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 certain 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 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.
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 an un vast universe. Right, So go ahead, bonk that guy with a rock. Nothing really matters, you know, but one step at a time, let's go all 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?
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 we what we always do, of course, and the deal in science is you have a theory and then you assess how it interfaces with the facts. 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 numatt Elish there's this I did, the goddess Tiamat was split in half and half of us stretched into the heavens, and that that is the heavens.
You know, back up, tell us what this document is. You referenced it, but it's not something I'm familiar with.
Holy documents from the ancient Near East, you know, where were the cradle of civilization? You 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?
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 like there's the other one I mentioned, well, the three I mentioned is this one from ancient Babylon or an ancient Near East, and one from ancient China, although Chinese 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 fascina, Like the one from ancient China is just about like this is this story about a giant who just sort of carves up the universe till there's like till there's a.
Sky and the ground, and then he dies.
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.
Maybe 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.
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 just about the way we think. It's 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, 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 built deeply into their brains, and so they thought about, you know, the Earth is the center 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 sort of blows my mind.
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 it's important to philosophy.
Yeah.
Yeah, Plato's academy, Who's 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 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.
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 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 sort of like just does it make sense from a very basic geometrical standpoint, And there are some evidence in writing or people like it put this together and be like, hm, just doesn't make sense. I don't know, and they just want to move on.
I wonder with 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.
Some of the things.
It's not really relevant if it's quite accurate in that particular sense.
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 a 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?
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. 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 sits in the book somewhere.
Yeah, it's like almost the eighteenth century before we can actually see the stars.
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.
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 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 or Samas who said, you know, the Sun's in the middle of the Earth goes around it, and even suggesting the Earth was tilted on its axis, which is pretty darn cool. But of course that theory can't explain a bunch of stuff that the aristol theory does explain, 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 miner field. That's not pre intuitive, but it would make perfect sense right back then, I suppose that, like why don't I feel the wind blowing on my face?
Why why woun't I drop something?
Does it just go straight down if I'm like going around this racetrack?
You know?
So there are actually good, good arguments for Aristotle's position over against Aristartus.
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 exactly. You 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.
That's right, yeah, exactly.
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 cleverest 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 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.
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 a snap 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, 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. With big wireless providers, what you see is never what you get. Somewhere between the store and your first month's bill, the price you thought you were paying magically skyrockets. With mint Mobile, you'll never have to work about gotcha's ever again. When mint Mobile says fifteen dollars a month for a three month plan, they really mean it. I've used mint Mobile and the call quality is always so crisp and so clear. I can recommend it to you, So say bye bye to your overpriced wireless plans, jaw dropping monthly bills and unexpected overages. You can use your own phone with any mint Mobile plan and bring your phone number along with your existing contacts. So dit your overpriced wireless with mint Mobiles deal and get three months a premium wireless service for fifteen bucks a month. To get this new customer offer and your new three month premium wireless plan for just fifteen bucks a month, go to mintmobile dot com slash Universe. That's mintmobile dot com slash universe. Cut your wireless bill to fifteen bucks a month. At mintmobile dot Com slash Universe, forty five dollars upfront payment required equivalent to fifteen dollars per month New customers on first three month plan only speeds slower about forty gigabytes on unlimited plan. Additional taxi spees and restrictions apply. See mint mobile for details.
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To the extent that's a fun job. Yeah, I like that job.
That's you guys over there work really hard. I'm just gonna sit here and make potshots at you.
Oh no, absolutely, you know, look, this is all about me. I'm just I'm just a jog especially making fun of chemists. Chemists is just really it's just really satisfying.
Ooh, you gotta be careful. I made some comments about chemistry on this podcast, and I got some emails.
Let me tell you, Oh boy, they're dangerous too. They know how to blow stuff up.
So 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 I 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.
Okay, well you know what.
Here's 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 chemistry, it's like it's this unholy hybrid where they are almost rules. Did I ever tell you I was this is ages ago, I was in them. I were talking to chemistry professors shared 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, what you or I would have done, which is he was. The story I was told was that he began with the shortingear equations.
In principle, you can derive all of chemistry from that.
That's right, that's right. Just it's an exercise for the student.
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 forget 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 Greeks got it wrong, and the sort of ancient picture of the Earth at the center of the universe was wrong. And but let's talk about how we figured that out and sort of like the steps so long 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.
Yeah, for me, this was maybe the most interesting part of the book, at least that didn't involve modern cosmology, which was like, so you know, the story that I think I was told was one you go to Claudius Ptolemy and like everybody who does now, but as 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 Aristotle's you know, spheres within spheres model, but with these little modifications to make the planets behave and it's it's quite a.
Good model, and it rains for you know, over a thousand years, 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 ha, but like this thing really worked, it really works.
Yeah, I always want to say that the funny thing is, I mean there's stuff like this right now or where we like, so 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, as I understand it, is just that like, well, one, of course they don't actually exist. That's a non tripa but like.
That's a detail.
But beyond that, it's.
Also just like it's 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.
Othough 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 iss you except this blew my mind.
I'm sure cosmologists all know this, but so 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, 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 when 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 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 tico'brahe and I 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 you audio just 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 Tinko brahe thought, is there's Earth in the middle, and then if you can imagine it far out, you got the Sun going around the Earth, and then around the Sun are the other space objects, the other planets, which is kind of amazing.
It's genius. Is genius when like, let's keep the Earth at the center while solving the problems of the data.
That's what I love about 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 what 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 tooever, you can talk about there's certain tensions in modern cosmology, like you know, my understanding is the reason and I won't get too far ahead of his.
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 it's interesting because it's not quite the same as saying there should be perfect spheres or you know, that there should be in the center. But there are kind of vibes about these things about like what what what is attractive to us?
But what's also.
Funny, though, is that Brahy 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.
I think it was more of a holy hybrid.
Right.
He wanted to at the center, right, 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 be 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 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. Remember I was rereading it. 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 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 just like writing the.
One sentence I needed.
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.
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 out there, 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.
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 it 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 forbatim the way I like to say it, which was that you liked 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, and 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 thingk. I'm sure I blew it on something.
But like you know, I did, 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.
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's 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, 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 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 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 proved that the Sun is at the center, you're right, it's not accurate. You can have bases and actually have the Earth at the center of the system.
Is fascinating, totally fascinating and related to that.
Once story that was amazing to me is the story about part of another thing Galileo did 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 there's peaks and valleys and stuff. And what's interesting 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 about.
Like where things are.
But minds saying is that was very important because it's like, if you're existing in this paradigm where these are sort of the divine spears 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, 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 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 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 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 imagine Kepler just kind of like looking at tables and somehow these ideas are and said, it's it's incredible.
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 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.
Yeah, that's interesting. It's you 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 tell this story that is 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. They were the ones who said here is the grand synthesis, And so that's hatching to me because like, I, you know, just just just reading about Newton, who I think you know, there's at least the story 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 use like the same math and it just pops out all this other stuff, including kepler stuff.
Which is just you know, so amazing.
And by the way, my fair detail about that too is this story that like that like I was playing 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 modern science. I don't know, maybe there's someone like that monitor So there's probably someone out there who 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.
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, 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 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 permitted wrong, so let's hang on to it as long as we can, right, Yeah.
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 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.
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All right, we're back and we're talking to Zach Wider Smith about why ancient scientists have gotten me wrong and why modern scientists are probably also going to be made fun of in future joke books about the universe.
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 it today, mm hmm.
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 are galaxy is just like ours, but they don't know what they are.
And this, to me is like this incredible period of history. And 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.
What a unit of time, that's right?
Yeah, So to 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, 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 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 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, the story I was planning to tell, was just like, well, Hubble comes along, says red shifting and therefore the universe of spanning, right, because 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 his 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 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 someone pretty easily. You could draw a picture and be like it's like this, you know, and people would basically get it. But then you say everything in space is moving away 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 there's a 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 bread one.
You know this one?
I love that metaphor. Yeah, that one works really well.
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 the raisins are getting close to each other until you have some sort of culture deaths, raisiny something, you know, and like the bread has gone away or I don't know.
It changes phase into a raisin plasma.
That'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 raisin.
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 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 ammenty all this happens in like a 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 whole universe. Your conception of it just 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. 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.
No, it definitely doesn't. And I think you're right that we transition 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 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 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 fudgebackor right to like balance up against that, which, if you look at it is like kind of a terrible theory and like it's really pretty 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 is right, and so then we're like, hm, well that's interesting. You know, why would it 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 slower due to that gravity. Right, So Einstein still didn't really have a grip on what was happening, and it took a 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, because I think you ran into some of these we're 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 a and then it exploded through space and filled everything out. I hear that all over the place. People ask me, like, where was that dot? Where was the center of the universe? Can we see it?
Right?
It's like a really common misconception. You must have run across this also in your research.
Yeah, I mean 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 get to do. Is this idea of infinitely this or that as being a real thing? But like, yeah, I was 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 tease 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 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 Lamitra, who's the guy who's fame for proposing this, didn't believe that himself.
He used the term primeval atom.
But my understanding is he meant atom is something like fundamental, not as the size of an atom, And 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 also because we use singularity to mean infinitely tiny when we talk about like a black hole, right, we say there's a singularity to 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 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, It was everywhere, everywhere, much bigger bang than anybody ever thought of.
Is it's not so much weirder, right, Uh? Like, I don't know. I mean, maybe it's just 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, know what happened everywhere at the same time, I don't know what to do with that, Like, my brain just doesn't work on that.
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.
Right, Yeah, But what's maybe this will get us to the sort of the whole steady state stuff, is there is this weird thing where 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 an like do you have a gut reaction like like separate from what you know is true or think to be true?
Like what like do you have a gut reaction about? What is more satisfying to me?
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.
You see the pribt is I this is just like being a weird human. But you're just like my instant thought is like, well, what start at this eternal universe? And you're like, oh no, wait, I can't ask that, you know.
Exactly, it's like defining their grounds of debates that your question is no longer valid.
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, 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 this this eternal model called the steady state model, which and then then this 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, both these theories could explain this expanding universe we have, it's just working in a different way. And this is where it's 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 Newton 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.
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 GAMMAO 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 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 they're pretty good ratios. And what was issuing 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 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's you know, it requires ever more special pleading.
And that's what for me.
So I'd known about the cosmic micromative 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 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'd 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 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 silence, you.
Know, especially because the Big Bang model could the cosmic background radiation, which is really powerful.
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 accommodate all sorts of things, but would require you to make a roup goldbrig machine, you know, of like special stuff that happens for no reason, which to me is just you know, it's sort of fascinating because you know, a story will be told that's just something like just causing 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.
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 thigh 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 of creation 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, we don't know if this's quantum gravity, we don't know if there's an infloton field. It just basically shrug and they say, but 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, 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 what people imagine the Big Bang is and what it is is in like actual science.
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 mean is that, like the equations we have with the 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 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.
To me, it's like a seg fault, right, you run your computer and the program crashes. You know, 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.
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 cash or a 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 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 discrepancy 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 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. That's a good point, Like black holes people are like black holes. Nah, there's no way the universe lets that happen. Okay, it turns out and bat black holes are kind of a big deal.
Yeah, that's that's an interesting point.
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.
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 about the shape of the universe. Well, well, okay, so.
Could a visual person not worry about shapes?
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 so it's like, I mean, obviously it's an aesthetically interesting question, right, And then 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, 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 helped talk me through this as a couple other people, is this 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 it could 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 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 we can say spear, 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. And that's actually true for all these models, like the sheet 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.
These shapes that get presented to you in a pop setting, or I would saying mistle, I think they confused me because I started understand well, like why can't one do the other, and like what would it sort of feel like to be in one 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 also like why why why?
Why is this question interesting other than again the pure esthetics, And that's what where the history gets really interesting because it turns out, you know, uh, spoiler, that observations seem to suggest we're in a flat universe.
Flat flat again, like being not the preferred term. I forget.
We would say, like, I know, you say positively curve of negatively curved, what would you say?
I guess, I guess it's okay to say flat.
Yeah, zero curvature and flat zero courverature.
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 of somewhere in positive curvature or somewhere in negative curvature. We're in a flat So it's 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 to me it gets fascinated. 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 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.
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 that would be one of you.
I want to know our context, like what is 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.
Yeah, what it would be your number one?
What would be my number one?
You get five questions, You're like, you're your top.
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 tiny, little non eternal brain.
Yeah, totally.
Seven extent I wondered this or the 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? To me?
It burns that there are facts about the universe that exist that are out there that we do not know. So yeah, that really 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, says Yeah.
I've been visualizing all the cosmologists like just walking around angrily all the time.
So what do people go if they want to buy the universe a Bridge beyond Usefulness? And also your new book with Kelly, 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 cityo Mars dot com, then you can get other options like powells and indie books and cool stuff like that.
Just go to your beloved local bookstore. That's the best option of all awesome.
Well, I recommend everybody out there get Zach's book on the Universe Abridged, 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 Zach. Before I let you have one more question for you. Why do cartoonists want to write books about cosmology?
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 cartoons 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.
This is a surprisingly high number of physics dropouts in the early cartooning community, so it was entirely predictable from the late nineties that this would happen.
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 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. When you pop a piece of cheese into your mouth, you're probably not thinking about the environmental impact. But the people in the dairy industry are. That's why they're working hard every day to find new ways to reduce waste, conserve natural resources, and drive down greenhouse gas emissions. How is us dairy tackling greenhouse gases? Many farms use anaerobic digestors to turn the methane for manure into renewable energy that can power farms, towns and electric cars. Visit you as dairy dot COM's Last Sustainability to learn more.
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