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Speaker 1: Hey, Daniel, did you see that amazing volcano that erupted

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Speaker 1: in Iceland? Is that the one in oh Nice? Is

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Speaker 1: that how you say it in Icelandic? I don't actually

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Speaker 1: speak Icelandic, though I do speak some Danish. Icelandic is

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Speaker 1: more like old Norse. But Iceland, the country is super

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Speaker 1: awesome and filled with volcanoes. Yeah, and there's one right now.

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Speaker 1: It's spewing hot lava like as we speak. Yeah, it's

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Speaker 1: like the Earth is breathing out more like burping or vomiting.

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Speaker 1: The Earth got indigestion, I think I wonder how you

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Speaker 1: say indigestion in Icelandic. It's just a volcano. I am

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Speaker 1: more handmade cartoonists and the creator of PhD comics. Hi,

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Speaker 1: I'm Daniel. I'm a particle physicist, and I'm substantially less

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Speaker 1: gassy than the island of Iceland. Are you less gassy

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Speaker 1: than the average physicists? No comment? Are you all full

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Speaker 1: of I'm more full of hot area exactly. But welcome

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Speaker 1: to our podcast. Daniel and Jorge Explained the Universe, a

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Speaker 1: production of I Heart Radio in which we blow your

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Speaker 1: mind into tiny, little hot pieces of gas by talking

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Speaker 1: about all the crazy stuff that exists in our universe.

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Speaker 1: We go way way back to the very beginning of

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Speaker 1: the universe. Talk about how all that happened, how it

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Speaker 1: led to this crazy, beautiful structure that we see today,

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Speaker 1: and what progress we've made in unraveling that structure and

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Speaker 1: understanding the fundamental nature of matter and space and time,

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Speaker 1: and of course what the open questions are still. Yeah,

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Speaker 1: we are here burping out amazing facts about the universe

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Speaker 1: and expelling them out into the atmosphere for all of YouTube.

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Speaker 1: Breathe in to your brains and absorb them and hopefully

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Speaker 1: get nursed with some amazing pruce about the universe. That's right.

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Speaker 1: We want these hot truth to roll over you like

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Speaker 1: lava floating out a volcano. But you know, we're hoping

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Speaker 1: not to burn you too much. Things are getting kind

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Speaker 1: of hot, Dannie, I love it. I love it, and

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Speaker 1: I love it, and who doesn't love lava. But yeah,

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Speaker 1: it's a pretty big universe, and we are just this small,

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Speaker 1: tiny little planet floating in the middle of mostly emptiness,

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Speaker 1: careening through the space, ready to be hit by an

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Speaker 1: asteroid perhaps. And this planet has a long and illustrious history.

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Speaker 1: It hasn't looked the way it currently does for most

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Speaker 1: of its life. We don't think of the Solar System

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Speaker 1: and the galaxy is changing very much. They seems sort

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Speaker 1: of static. But on a cosmological time scale, things are crazy,

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Speaker 1: things are chaotic, things are changing all the time. Yeah,

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Speaker 1: it's easy to think when you look out into the

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Speaker 1: universe and to the stars that things are always the

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Speaker 1: way they are right now. But no, actually, the universe

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Speaker 1: is very dynamic, and it's changing, and it's constantly evolving,

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Speaker 1: which tells us something important about what is gonna be like.

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Speaker 1: If we want to know what the future Earth is

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Speaker 1: going to be like and whether he means can still

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Speaker 1: live on it, we better dig into its past and

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Speaker 1: understand how it got to be such a warm and wonderful,

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Speaker 1: cozy place to live. Yeah, what are we gonna be

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Speaker 1: burping in a hundred million years perhaps or having indigestion

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Speaker 1: with Yeah, So the Earth has an amazing history, and

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Speaker 1: so one part of the Earth that's very important to

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Speaker 1: us is its atmosphere. I count on it every day breathing.

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Speaker 1: It fills me with life every single moment. Really, when

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Speaker 1: you think about it, No, absolutely, we rely on it

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Speaker 1: every single day. Well, we couldn't live without it. It

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Speaker 1: feeds not just us, of course, but all the things

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Speaker 1: that we eat drink. The atmosphere. It's a very complex

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Speaker 1: and elaborate system of pumping gases out of plants and

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Speaker 1: into plants and out of the ocean into the ocean.

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Speaker 1: It's an amazing and complicated system, and it's incredible that

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Speaker 1: it works at all, frankly, and then it's even at

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Speaker 1: all stable. Thank goodness, we haven't because without an atmosphere,

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Speaker 1: we wouldn't be here. We wouldn't just be out of

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Speaker 1: breath and choke to death, but we would also be

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Speaker 1: a pretty toasted thanks to all of the radiation coming

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Speaker 1: from space. That's right, themospheres here. He keeps us warm

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Speaker 1: and acts like a blanket and also acts like a

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Speaker 1: shield protecting us from so many rocks and particles and

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Speaker 1: all sorts of stuff coming from space. So it's a

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Speaker 1: pretty important part of life here on Earth today and

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Speaker 1: hopefully it'll stick around for another billion years or so. Yeah,

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Speaker 1: and we should appreciate it because it wasn't always here

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Speaker 1: on Earth. The Earth didn't always have an atmosphere. There

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Speaker 1: was time and the history of Earth that we were

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Speaker 1: basically naked right out in space nothing to drape over us.

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Speaker 1: That's right. If you build a time machine and you

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Speaker 1: want to see the early Earth, don't neglect to bring

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Speaker 1: your space suit, because if you go back to three

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Speaker 1: four billion years into Earth's history, you're not gonna be

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Speaker 1: able to breathe whatever was on the Earth, if there

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Speaker 1: even was anything. Yeah, and so a big question would

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Speaker 1: be how did it get this way? How is it

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Speaker 1: that we have this beautiful and fresh well depending on

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Speaker 1: where you live, fresh air for us to take in

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Speaker 1: and enjoy and live with. It's a fascinating story that

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Speaker 1: dates way back to the very beginning of the Solar

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Speaker 1: System and involves lots of dramatic pauses like volcanoes and

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Speaker 1: the years and all sorts of other crazy stuff. So

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Speaker 1: today on the podcast, we'll be asking the question where

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Speaker 1: did the Earth get its atmosphere? Yeah? Where did it

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Speaker 1: get its airs? Daniel? It's ambiance, that's right. And it's

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Speaker 1: a very very fine place to hang out. It's very airy,

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Speaker 1: it's very blue and transparent. I love what you've done

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Speaker 1: with the place, really, Dole are burping apparently, I'm guessing

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Speaker 1: maybe does that count as interior design if you're designing

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Speaker 1: an entire planet or is it the still exterior design.

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Speaker 1: I guess it depends. Are you like an alien shopping

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Speaker 1: for planets? Are you like an earthling looking around? I'm

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Speaker 1: imagining the aliens come, they take over the Earth, and

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Speaker 1: they don't really like what we've done with the place,

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Speaker 1: and they want to fix it up a little bit.

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Speaker 1: So they hire some like massive geoengineering firm to do

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Speaker 1: the equivalent of interior design, but for the whole planet.

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Speaker 1: I wonder if that would be like a future career, like, hey, mom,

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Speaker 1: I want to be a geo designer or a geodecorator.

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Speaker 1: That's right, Mars has been using that same shade of

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Speaker 1: red for like a billion years. It's time to pick

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Speaker 1: a fresh color. How about cyan or a nice mango glaba.

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Speaker 1: You need always three words in every name for a

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Speaker 1: shade of paint, you know, wild Mountain, raspberry or something

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Speaker 1: right that, so you can sell more of them, to

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Speaker 1: be honest, because maybe you just sell red and blue,

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Speaker 1: you're out of business. Well, if you're covering a whole planet,

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Speaker 1: I think you're gonna sell a lot of gallons of paint.

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Speaker 1: So yeah, So the Earth didn't always have the atmosphere

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Speaker 1: that we're breathing right now. It used to be a

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Speaker 1: pretty inhospitable place, right, that's right. It used to be

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Speaker 1: a place where humans or animals could not survive because

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Speaker 1: I guess initially, you know, we formed around a brand

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Speaker 1: new Sun and we were just a bunch of rocks

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Speaker 1: and gas kind of gathered together by gravity. Right. Yeah,

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Speaker 1: everything in the whole Solar system, of course, came from

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Speaker 1: the same big cloud of gas and dust to form

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Speaker 1: the Sun and the planets and everything. But the story

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Speaker 1: is a little bit more complicated. Yeah, So we were wondering,

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Speaker 1: as usual, how many people out there know the story

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Speaker 1: of our atmosphere and now how we got to have

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Speaker 1: the air that we have. So, as usual, Daniel went

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Speaker 1: out there into the wilds of the internet to ask

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Speaker 1: people where did Earth get its atmosphere? And so, as usual,

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Speaker 1: if you'd like to participate by answering funny questions with

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Speaker 1: no preparation, please write to me two questions at Daniel

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Speaker 1: and Jorge dot com. Trust me, it's fun. Here's what

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Speaker 1: people had to say. I gotta guess from rocks during

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Speaker 1: the heavy bombardment period when they guesses got released into

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Speaker 1: the atmosphere. But the oxygen and atmosphere, which actually a

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Speaker 1: lot higher today, came from I think it's Sanda bacteria,

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Speaker 1: those rocks in Australia that the first thing is to

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Speaker 1: photosymphasize and actually caused a huge distinction event um And

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Speaker 1: the Earth was just formed. It was hot, and I

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Speaker 1: think there were many chemical reactions going on away her

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Speaker 1: atomic reactions and all. So maybe because of the reactions,

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Speaker 1: I think probably they were just hydrogen and helium in

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Speaker 1: the beginning, but then due to all these reactions, all

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Speaker 1: the different gases will formed. Then maybe that's how we

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Speaker 1: got that atmosphere. Let's say we have lots of nitrogen

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Speaker 1: that prevents everything from blowing up. Then we have some

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Speaker 1: oxygen and some argon. And that's about what I know

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Speaker 1: about earth atmosphere. I can't really tell you where it

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Speaker 1: comes from. I think the atmosphere came from volcanic activity

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Speaker 1: when the Earth was young, and I know that the

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Speaker 1: oxygen came from cyanobacteria producing it when life just got

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Speaker 1: started on Earth. Well the proto or it was very

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Speaker 1: very hot, so I would say that the burning and

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Speaker 1: the temperature itself would cause gases to form that would

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Speaker 1: accumulate around the Earth, being trapped in its gravitational field,

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Speaker 1: and once the Earth cooled, the composition of the those

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Speaker 1: gases must have changed, especially when life started to arise

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Speaker 1: and would start to change the atmosphere and take out

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Speaker 1: garbon dioxide and fill it with oxygen. I think they

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Speaker 1: say Mars used to have an atmosphere. Maybe we stole

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Speaker 1: mars atmosphere here have it on Earth now. Our atmosphere

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Speaker 1: came from all the various eruptions on the Earth. In

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Speaker 1: other words, the Earth's hot are the biggest contributor easy life.

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Speaker 1: You fount organisms reciting the various chemicals from the atmosphere,

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Speaker 1: apart from the atmosphere easily blanged by absorbing common trails

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Speaker 1: and volcano emissions. I'm assuming, like ah, the formation of

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Speaker 1: the Earth, there was a bunch of like dust and

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Speaker 1: rocks and like just surrounding chemicals, and the Earth kind

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Speaker 1: of lumped together. The rocks lumped together created kind of

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Speaker 1: some strong gravity, and like particles and like air particles

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Speaker 1: were like, hey, there's some gravity here. I guess let's

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Speaker 1: like stick around, stick to it. And that's what happened. Alright.

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Speaker 1: A lot of pretty detailed answers. You people have thoughts

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Speaker 1: on the topic. Yeah, they have air, They have a

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Speaker 1: lot of things to say about how we got our atmosphere.

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Speaker 1: That's pretty cool. Do you think it's out there in

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Speaker 1: the popular culture kind of the history of our atmosphere? Yeah?

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Speaker 1: Or you know, maybe it's just so immediate people think

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Speaker 1: about it. They literally breathe it in and out every day.

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Speaker 1: So it's not some like weird, abstruse topic that only

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Speaker 1: physicists wake up late at night thinking about. It's something

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Speaker 1: everybody thinks about. And these days with all the discussion

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Speaker 1: of global warming and climate change, it's something that people

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Speaker 1: really do think about what's in the air and how

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Speaker 1: we can influence it. And I guess it's kind of

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Speaker 1: interesting that nobody was surprised. Nobody was like, what, we

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Speaker 1: didn't always have an atmosphere? Like people seem to know

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Speaker 1: that it came from somewhere. Yeah. Somebody even suggested we

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Speaker 1: stole it from Mars. No way, what is it? Hot

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Speaker 1: airror air? Hot exactly. They're gonna come looking for it,

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Speaker 1: bring it pulled over with a vacuum and suck it

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Speaker 1: all back up. So do you have a receipt for

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Speaker 1: this atmosphere? I do. I just lost a seven billion

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Speaker 1: years ago. Who keeps records that long anyway. Yeah, so

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Speaker 1: it is an interesting story how we got our atmosphere,

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Speaker 1: and so it's interesting to think that that wasn't always

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Speaker 1: the case. You know, we were just a little barren

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Speaker 1: rock floating out in space with some gas. Right. Yeah.

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Speaker 1: It's really a fascinating story because the Earth has had

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Speaker 1: different atmospheres through its history. Like if you took a

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Speaker 1: time machine back to the very very early hot Earth,

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Speaker 1: you'd experienced something very different from if you went back

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Speaker 1: like three billion years ago or one billion years ago.

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Speaker 1: So it's really it's a fascinating, very very dynamic story

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Speaker 1: with lots of twists and turns. Yeah, and it's not

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Speaker 1: just like a different temperature maybe, or like twists in

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Speaker 1: the composition. It's like a totally different set of gas

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Speaker 1: that was enveloping the Earth. Right, Yeah, we have like

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Speaker 1: atmosphere three point oh these days we're not breathing the

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Speaker 1: original atmosphere or even the second atmosphere. We're lacked on

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Speaker 1: the third version of the atmosphere. It's been upgraded twice already. Well,

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Speaker 1: do you think we got it this time or do

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Speaker 1: you think we're do for an upgrade? I'm pretty happy

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Speaker 1: with it. I got no notes like do we have

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Speaker 1: to schedule the update? You know? Can we schedule it

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Speaker 1: for like a billion years from now and when we're

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Speaker 1: not around. Well that's the problem is sometimes you know,

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Speaker 1: you're happy with your version of your operating system and

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Speaker 1: then it updates itself and you're like, no, don't change anything.

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Speaker 1: It was great. Do we have auto update on? Maybe

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Speaker 1: we should turn that off because sometimes things don't work

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Speaker 1: the same, you know, that's the solution of climate change.

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Speaker 1: Rather just untake that box on the atmosphere operating system

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Speaker 1: that says no updates please. All right, everybody stopped breathing

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Speaker 1: for about a hundred years and then we'll get anyone.

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Speaker 1: We're gonna reboot. Yeah, all right. Well, so you're saying

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Speaker 1: this is not our first atmosphere. Um, we're in the

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Speaker 1: third version. So what was the first version of the atmosphere?

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Speaker 1: So the first version in the atmosphere formed when Earth

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Speaker 1: formed itself. As we were saying before, everything in the

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Speaker 1: Solar system came from the same basic constituents. You have

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Speaker 1: this huge cloud of hydrogen mostly in a little helium

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Speaker 1: and trace heavier elements, and that whole thing got sparked

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Speaker 1: into a collapse, which led to the formation of the

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Speaker 1: Sun of course, which is a huge ball of hydrogen.

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Speaker 1: And then the planets gathered together and all basically came

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Speaker 1: out of the same stuff, and you had planets formed

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Speaker 1: because you had like little rocky cores that gathered together

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Speaker 1: and gradually pulled other stuff along with it. And so

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Speaker 1: what was Earth's atmosphere when it first formed, Well, the

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Speaker 1: only gases around really were hydrogen and helium mostly, So

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Speaker 1: just like Jupiter and the Sun and the other gas

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Speaker 1: giants have big atmospheres mostly of hydrogen with a little

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Speaker 1: bit of helium, Earth also had a helium hydrogen envelope

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Speaker 1: around it when it first formed, right because I guess

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Speaker 1: you know, the whole area in space was covered in

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Speaker 1: hydrogen and helium and most of it went into the Sun,

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Speaker 1: but I imagine some of it sort of hung out

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Speaker 1: around the little rocky planets that were forming. Yeah, but

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Speaker 1: not for very long. So what happens is these things

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Speaker 1: are forming and they're collapsing, and there's sort of a race,

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Speaker 1: Like the Sun is gobbling up a huge amount of

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Speaker 1: this stuff, and the gas giants are out there, they're

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Speaker 1: gobbling up a lot of it. And here in the

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Speaker 1: inner Solar System, it turned out to be pretty hard

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Speaker 1: to hold onto any gas because you're competing with the

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Speaker 1: Sun that's slurping up all of the hydrogen as much

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Speaker 1: as it can, and you don't have the gravity that

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Speaker 1: like Jupiter has because the inner part of the Solar

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Speaker 1: System is warmer, so there's no like rock ice to

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Speaker 1: help you build a planet rapidly to grab some of

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Speaker 1: that helium and that hydrogen. So out in the outer

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Speaker 1: part of the Solar System where Jupiter was, you had

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Speaker 1: rocks formed together but also with ice that let them

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Speaker 1: see these larger planets that could hold onto their hydrogen.

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Speaker 1: But here in the inner Solar System, Earth was just

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Speaker 1: sort of like too small to really hang onto its hydrogen,

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Speaker 1: so it was very short lived atmosphere. I guess maybe,

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Speaker 1: like you know, lighter elements like hydrogen and helium, they

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Speaker 1: get more easily sucked in by the Sun and other

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Speaker 1: planets than the rocks that we have, right, that's kind

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Speaker 1: of what happens is that you know, it's so light

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Speaker 1: that they can just leave and get sucked in by

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Speaker 1: the Sun. But whereas the rocks, it's harder for the

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Speaker 1: Sun to have pulled us in that's exactly right. And

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Speaker 1: there was also an opposite effect because once the Sun

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Speaker 1: started burning, it was producing a solar wind, which is

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Speaker 1: a huge amount of radiation that then blew off the

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Speaker 1: rest of our atmosphere. Right, we had no magnetic field

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Speaker 1: yet to protect ourselves from these things. Magnetic field is

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Speaker 1: formed when layers inside the Earth are like mixing and

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Speaker 1: blending and spinning. But the Earth was too young to

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Speaker 1: have like differentiated and had these nicely divided layers that

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Speaker 1: could produce a magnetic field. And so the solar radiation

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Speaker 1: also blew off any gas that we did manage to grab.

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Speaker 1: So initially we had a little bit of gas around

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Speaker 1: our kind of brand new Earth, but then it quickly

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Speaker 1: either left or it got blown away. Yeah, so this

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Speaker 1: first atmosphere was very very short lived. I'm not even

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Speaker 1: really sure you could say they was like settled down

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Speaker 1: before it got slurped up by the Sun and then

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Speaker 1: blown off by the solar radiation. Yeah. I feel like

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Speaker 1: there's a lot of gas and wind in this story

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Speaker 1: is getting a little um you know, gastric here, not

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Speaker 1: just cosmic dig a tums. But there was a lot

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Speaker 1: of stuff going on, like the early solar system was

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Speaker 1: a very chaotic place, and it could have gone in

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Speaker 1: lots of directions. You know, you could have had a

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Speaker 1: planet here or a planet there. The reason we have

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Speaker 1: a planet exactly here depends on a lot of very

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Speaker 1: small chaotic factors that depended just on like the distribution

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Speaker 1: of the initial stuff. But a little bit more clumpy

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Speaker 1: or there, you would have got a different set of planets.

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Speaker 1: All right, So then we had a little bit of

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Speaker 1: hydrogen and helium, but then that quickly went away, and

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Speaker 1: so what was our second atmosphere? So then the Earth

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Speaker 1: was barren, right, we had just a ball of rock

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Speaker 1: with really no atmosphere to speak of. Say this period

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Speaker 1: here where the Earth is like naked. There's just no

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Speaker 1: atmosphere protecting the surface of the Earth from basically space.

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Speaker 1: And you know, interestingly, I talked to some geologists, and

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Speaker 1: they don't see the Earth as naked in that sense.

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Speaker 1: Like for them, the atmosphere is part of the crust.

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Speaker 1: It's just like a different kind of crust, you know.

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Speaker 1: They don't think of it as like the crust ends

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Speaker 1: at the surface and then you have atmosphere. The atmosphere

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Speaker 1: is just sort of like part of the crust. Because

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Speaker 1: there's like constant interchange between the atmosphere and the surface,

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Speaker 1: and it's just like you know, another layer of the earth. Sure,

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Speaker 1: I guess two a geologist. They want it all, they

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Speaker 1: want it all there like the air. That's part of

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Speaker 1: my grant proposal as well. It's part of geology. Of course,

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Speaker 1: humans where also geology. We are part of geology. Absolutely,

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Speaker 1: we are part of the crust. And that's where this

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Speaker 1: outer gas la or the crust that we call atmosphere

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Speaker 1: came from when it was replenished. It was replenished from

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Speaker 1: inside the Earth because volcanoes like the one in Iceland

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Speaker 1: and the other ones around the Earth out gased like

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Speaker 1: internal processes inside the Earth lead to these explosions and eruptions,

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Speaker 1: which can produce enormous quantities of gas. Meaning like was

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Speaker 1: all this gas forms inside of the Earth or it

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Speaker 1: just got trapped as the Earth was sort of forming

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Speaker 1: and all those rocks, actual rocks were coming together. Yeah,

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Speaker 1: it's all in there, and it's all mixed together. You know,

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Speaker 1: you have carbon, you have sulfur, as, you have oxygen.

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Speaker 1: These are all the elemental ingredients of the Solar system,

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Speaker 1: which are then compressed and mixed together. There's a lot

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Speaker 1: of chemistry going on. So these elements all mixed together

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Speaker 1: in the way that's like energetically most favorable. But then yeah,

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Speaker 1: they get spewed up from underneath the earth, and you know,

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Speaker 1: these rocks have gases dissolved in them sometimes and then

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Speaker 1: those can come out when there's less pressure or I

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Speaker 1: guess as maybe as things were sort of churning and

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Speaker 1: coming up from the surface, then the gas was able

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Speaker 1: to escape the rock. Exactly. Large gas bubbles exactly can

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Speaker 1: make their way up through the crust and then emitted

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Speaker 1: by the volcanoes. I mean, that's why volcanic eruptions happen, right.

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Speaker 1: We talked about this in a recent episode on most

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Speaker 1: massive volcanoes in the Solar System. When you have lava

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Speaker 1: that has like a lot of silica dissolved into it,

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Speaker 1: then it becomes like very sticky and it can absorb

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Speaker 1: a lot of gas, and then the gas builds up

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Speaker 1: the pressure and then it erupts and the gas can

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Speaker 1: be freed. Right, And so that's how we got things

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Speaker 1: like water of water, vapor and CO two and hydrogen

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Speaker 1: open in the atmosphere. In that second atmosphere. Yeah, so

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Speaker 1: the second atmosphere is mostly as you say, water, vapor,

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Speaker 1: carbon dioxide, sulfur dioxide, and then a huge amount of

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Speaker 1: just nitrogen. And very importantly, there was no free oxygen,

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Speaker 1: no like O two molecules were floating around in the atmosphere.

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Speaker 1: So this second atmosphere is not something we can breathe

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Speaker 1: at all. It would be totally toxic. You took a

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Speaker 1: time machine back to this volcanic period of the Earth

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Speaker 1: and you took a deep breath as you stepped out,

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Speaker 1: you would die pretty quickly. Great, not a great place

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Speaker 1: to visit. No exactly what bring your space suit, you know,

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Speaker 1: no big deal. Packs of oxygen. Just pack oxygen for

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Speaker 1: fifty years. And there's one other source of sort of

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Speaker 1: basic ingredients for our atmosphere. In those early days, it

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Speaker 1: didn't just come from inside the Earth. There were some

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Speaker 1: deposits from outside the Earth because during this period of

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Speaker 1: chaos in the early Solar System, there's a lot of

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Speaker 1: stuff moving around. The planets were switching positions and passing

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Speaker 1: through the asteroid belt and passing through the asteroid belt

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Speaker 1: in the other direction, which led to a lot of

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Speaker 1: bombardment of the Earth by really big rocks. This is

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Speaker 1: called the late heavy bombardment, and some of those rocks

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Speaker 1: have water, and they have ice, they have other things

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Speaker 1: frozen into them which then evaporated when they hit the Earth. Interesting,

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Speaker 1: so those rocks had other sort of gaseous elements and

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Speaker 1: then when they hit the Earth, they made it into

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Speaker 1: our atmosphere. Yeah, just like we talked about how comets

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Speaker 1: probably replenished the Earth's water in a very same way. Right,

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Speaker 1: Earth had water when it formed, but then it boiled

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Speaker 1: off because we our atmosphere is very hot surface, And

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Speaker 1: we had a whole episode about how comics replenished the

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Speaker 1: Earth's water in the same way. Asteroids and other things

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Speaker 1: probably also replenished part of our atmosphere. Cool. All right,

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Speaker 1: Well let's get into how we actually got breathable oxygen

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Speaker 1: in our atmosphere and how we know all of these things.

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Speaker 1: How do we know the history of our atmosphere? But

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Speaker 1: first let's take a quick break. All right, we're talking

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Speaker 1: about the history of air. Basically, right, where did air

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Speaker 1: come from? And why is it so fresh to breathe? Yeah? Exactly,

401
00:20:42,920 --> 00:20:45,479
Speaker 1: something it's all around us. It's something that we rely on,

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Speaker 1: so we better understand why it's here and whether it's

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Speaker 1: going away. Yeah. Do you think air is offended when

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00:20:50,720 --> 00:20:54,320
Speaker 1: we sneeze or like cough, like you know, get it

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Speaker 1: out of my body? No, I think it's probably grateful.

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Speaker 1: It's like, oh, that's much more interesting. Who wants to

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Speaker 1: be inside of a wind warm human? All right, Well,

408
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Speaker 1: we had one atmosphere, but then it was blown away

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Speaker 1: by the sun and cosmic rays, and then we had

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Speaker 1: got a second atmosphere that was burped up from the

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Speaker 1: rock inside of the core of the Earth. And this

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Speaker 1: atmosphere had a lot of oxygen, but it which just

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Speaker 1: wasn't free oxygen like it was inside of C O

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Speaker 1: two and H two O or s O two, but

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Speaker 1: it was not something that we could use, like if

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Speaker 1: we breathe it that you wouldn't be able to get

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Speaker 1: that oxygen. Yeah, your lungs can't use that, right, even

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Speaker 1: though there's oxygen c O two, if you step into

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Speaker 1: a room that's pure CEO two, you're gonna fall unconscious

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Speaker 1: pretty quickly. Yeah, not good. Alright, So then that's our

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Speaker 1: second atmosphere. How do we get breathable oxygen? Then breathable

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Speaker 1: oxygen came from life, right, This was terraformed by tiny, tiny,

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Speaker 1: little microbes. But the first oxygen that was produced on

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Speaker 1: Earth wasn't actually from those microbes. The very first came

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Speaker 1: from ultra violet light that hit the Earth's atmosphere. When

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Speaker 1: you v photons, these are just really high energy particles

427
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Speaker 1: from the Sun and hit H two O molecules of water.

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Speaker 1: They can break it up and you can get ozone

429
00:22:05,280 --> 00:22:08,359
Speaker 1: formed in the atmosphere. And ozone is just a form

430
00:22:08,480 --> 00:22:11,840
Speaker 1: of oxygen. It's an O three molecule and it forms

431
00:22:11,880 --> 00:22:14,160
Speaker 1: in the upper atmosphere and it helps to actually shield

432
00:22:14,280 --> 00:22:17,600
Speaker 1: us from ultra violet light. So ozone again not something

433
00:22:17,680 --> 00:22:21,080
Speaker 1: you can breathe, but it's oxygen in the atmosphere which

434
00:22:21,119 --> 00:22:24,080
Speaker 1: then shielded us from UV which helped life I think

435
00:22:24,080 --> 00:22:26,720
Speaker 1: evolve a little bit interesting. So, like you just have

436
00:22:26,800 --> 00:22:29,720
Speaker 1: water molecules H two os there and then when it

437
00:22:29,760 --> 00:22:32,520
Speaker 1: gets hit by this light, it just breaks up, and

438
00:22:32,960 --> 00:22:35,439
Speaker 1: I guess breaks up. But then the oxygen doesn't go

439
00:22:35,480 --> 00:22:37,880
Speaker 1: into O two, it goes straight into OH three. Yeah.

440
00:22:37,920 --> 00:22:40,560
Speaker 1: In these chemical processes, you always get a mixture of everything,

441
00:22:40,920 --> 00:22:43,639
Speaker 1: but primarily this is how ozone is formed, and you

442
00:22:43,720 --> 00:22:45,720
Speaker 1: also get some other stuff forming. You know, you get

443
00:22:45,720 --> 00:22:47,840
Speaker 1: a little bit of O two but that's only responsible

444
00:22:47,880 --> 00:22:50,919
Speaker 1: for like one per cent of the oxygen in the atmosphere.

445
00:22:51,160 --> 00:22:53,320
Speaker 1: That's certainly not enough for us to breathe, all right,

446
00:22:53,359 --> 00:22:56,120
Speaker 1: but it did sort of form enough O two then

447
00:22:56,200 --> 00:22:59,200
Speaker 1: that you've kind of had to shield around Earth so

448
00:22:59,240 --> 00:23:02,840
Speaker 1: that you could, you know, evolve little organism that did

449
00:23:02,920 --> 00:23:06,240
Speaker 1: make well, it made O three, which is ozone, which

450
00:23:06,280 --> 00:23:09,280
Speaker 1: is primarily the shield. But exactly it provides a shield

451
00:23:09,320 --> 00:23:12,040
Speaker 1: to protect us from UV and that can like protect

452
00:23:12,080 --> 00:23:15,159
Speaker 1: the DNA of delicate little critters as they're evolving on

453
00:23:15,200 --> 00:23:17,840
Speaker 1: the Earth. All right. So then that's how we got

454
00:23:17,920 --> 00:23:20,880
Speaker 1: most of our oxygen then, is through bacteria and things

455
00:23:20,880 --> 00:23:23,400
Speaker 1: like that. Yeah, so bacteria have been around for quite

456
00:23:23,400 --> 00:23:25,520
Speaker 1: a while, turning away in the oceans of the Earth,

457
00:23:25,840 --> 00:23:30,240
Speaker 1: and at some point they evolved the ability to do photosynthesis, right,

458
00:23:30,480 --> 00:23:34,520
Speaker 1: to take sunlight and to combine the energy from sunlight

459
00:23:34,760 --> 00:23:37,840
Speaker 1: with C O two and water and to produce oxygen.

460
00:23:38,200 --> 00:23:41,680
Speaker 1: And when this happens, they're essentially producing fuel for themselves.

461
00:23:41,880 --> 00:23:43,800
Speaker 1: And so this is a really cool little thing that

462
00:23:43,840 --> 00:23:47,640
Speaker 1: they evolved. It's called cyanobacteria that first evolved this ability

463
00:23:47,680 --> 00:23:51,280
Speaker 1: to basically drink energy from the sun. And this started

464
00:23:51,320 --> 00:23:55,199
Speaker 1: about two points seven billion years ago, and that's a

465
00:23:55,359 --> 00:23:57,760
Speaker 1: very efficient way to turn c O two and H

466
00:23:57,800 --> 00:24:00,960
Speaker 1: two O into oxygen us. Maybe the you know, in

467
00:24:01,000 --> 00:24:05,960
Speaker 1: the primordial soup, you know, the earth was you know, inhospitable,

468
00:24:05,960 --> 00:24:08,280
Speaker 1: but there were little tiny things that could grow in

469
00:24:08,320 --> 00:24:12,040
Speaker 1: this environment in the oceans, and then that started turning

470
00:24:12,040 --> 00:24:15,480
Speaker 1: out O two. But that wasn't very beneficial for them, right, No,

471
00:24:15,600 --> 00:24:19,560
Speaker 1: it actually poisons them. Cyanobacteria are killed by the presence

472
00:24:19,600 --> 00:24:21,680
Speaker 1: of O two, and so if they make too much

473
00:24:21,680 --> 00:24:24,160
Speaker 1: of it, they kill themselves off. And again they don't

474
00:24:24,240 --> 00:24:26,240
Speaker 1: need O too. It's like a byproduct. It's a waste

475
00:24:26,240 --> 00:24:28,600
Speaker 1: product for them. But they wanted the CEO two, right.

476
00:24:28,680 --> 00:24:32,720
Speaker 1: Plants breathe CEO two and produce oxygen. Animals like us

477
00:24:32,960 --> 00:24:36,360
Speaker 1: breathe O two and produce c O two and cyanobacteria

478
00:24:36,400 --> 00:24:40,440
Speaker 1: they're not plants. They're like the precursors of photosynthesis in plants.

479
00:24:40,600 --> 00:24:43,119
Speaker 1: So they made a lot of oxygen, but that's not

480
00:24:43,200 --> 00:24:45,919
Speaker 1: quite the oxygen we breathe today, right, that's right. The

481
00:24:45,960 --> 00:24:50,399
Speaker 1: oxygen that was made by cyanobacteria originally didn't stick around

482
00:24:50,400 --> 00:24:53,800
Speaker 1: in the atmosphere because oxygen is super duper reactive. It

483
00:24:53,800 --> 00:24:56,520
Speaker 1: doesn't usually just hang out like if it can react

484
00:24:56,560 --> 00:24:59,280
Speaker 1: with anything around it, it will. So you have this

485
00:24:59,480 --> 00:25:02,960
Speaker 1: fresh earth covered in rocks, and these rocks are very

486
00:25:03,040 --> 00:25:06,120
Speaker 1: reactive with oxygen. Like imagine a bunch of iron out

487
00:25:06,119 --> 00:25:08,040
Speaker 1: there and you combine it with oxygen. When you get

488
00:25:08,200 --> 00:25:11,679
Speaker 1: you get rust. And so basically most of the oxygen

489
00:25:11,760 --> 00:25:14,399
Speaker 1: produced by the Earth and the first few hundred million

490
00:25:14,480 --> 00:25:18,280
Speaker 1: years was then breathed in by the rocks on the Earth.

491
00:25:18,480 --> 00:25:21,399
Speaker 1: They like sucked it all up. Wow, Like the Earth was,

492
00:25:22,240 --> 00:25:25,160
Speaker 1: you know, shiny and nice looking, and then suddenly these

493
00:25:25,200 --> 00:25:28,800
Speaker 1: bacteria breathed oxygen and everything rusted. Yeah, it was like

494
00:25:28,960 --> 00:25:32,040
Speaker 1: hundreds of millions of years where the Earth was getting

495
00:25:32,080 --> 00:25:35,800
Speaker 1: like a weatherized by all the oxygen that was being produced.

496
00:25:36,080 --> 00:25:38,080
Speaker 1: And you know how you talk about like free radicals,

497
00:25:38,080 --> 00:25:41,000
Speaker 1: etcetera in your body maybe causing damage and causing cancer.

498
00:25:41,359 --> 00:25:44,520
Speaker 1: That's all because of oxygen. Oxygen is very reactive. It's

499
00:25:44,520 --> 00:25:46,720
Speaker 1: like a crazy thing. It's going to touch and break

500
00:25:46,760 --> 00:25:49,800
Speaker 1: things near it. And so that's what happened when cyanobacteria

501
00:25:49,880 --> 00:25:53,560
Speaker 1: started pumping O two into the atmosphere, is that it's

502
00:25:53,600 --> 00:25:55,640
Speaker 1: starting to get absorbed by all these rocks and break

503
00:25:55,720 --> 00:25:58,200
Speaker 1: them down and weatherize them. And as you say, rust

504
00:25:58,320 --> 00:26:00,679
Speaker 1: the entire planet. I guess that's a process that they

505
00:26:00,720 --> 00:26:03,119
Speaker 1: had to happen, you know what I mean, Like, you

506
00:26:03,119 --> 00:26:05,760
Speaker 1: can't just have like a shiny, brand new rust free

507
00:26:05,800 --> 00:26:08,760
Speaker 1: Earth and also have oxygen. Like you're gonna put oxygen

508
00:26:08,720 --> 00:26:11,480
Speaker 1: in the atmosphere, you have to first, you know, rust

509
00:26:11,560 --> 00:26:13,919
Speaker 1: everything before you can breathe it. Yeah, everything is going

510
00:26:13,960 --> 00:26:15,920
Speaker 1: to drink of that oxygen. So if you want enough

511
00:26:15,920 --> 00:26:19,280
Speaker 1: floating around in the atmosphere for other things like animals

512
00:26:19,320 --> 00:26:21,040
Speaker 1: to breathe, then you've got to sort of like fill

513
00:26:21,160 --> 00:26:23,199
Speaker 1: up all the reservoirs out there that are just going

514
00:26:23,240 --> 00:26:26,359
Speaker 1: to gobble the oxygen so that there's enough to float around.

515
00:26:26,400 --> 00:26:28,840
Speaker 1: It's sort of like electrons and a semiconductor. You've got

516
00:26:28,920 --> 00:26:30,960
Speaker 1: to fill up all the lower energy levels so you

517
00:26:31,000 --> 00:26:33,760
Speaker 1: can have some floating around in the conduction band and

518
00:26:33,800 --> 00:26:36,680
Speaker 1: conduct electricity. Right, That was the first analogy I was

519
00:26:36,720 --> 00:26:42,920
Speaker 1: going to go with. I think these cyanobacteria are super amazing,

520
00:26:43,359 --> 00:26:46,359
Speaker 1: and I love how plants basically co opted them because

521
00:26:46,359 --> 00:26:49,680
Speaker 1: you know, the cyanobacteria, they evolved photosynthesis, and now when

522
00:26:49,720 --> 00:26:52,800
Speaker 1: we look inside plants, we see these little objects inside

523
00:26:52,800 --> 00:26:55,960
Speaker 1: a plant cell that can do the same thing, these chloroplasts.

524
00:26:56,320 --> 00:26:59,760
Speaker 1: But those things are basically cyanobacteria. They got co opted

525
00:26:59,760 --> 00:27:02,359
Speaker 1: by plants. The plants like eight them and said, okay,

526
00:27:02,400 --> 00:27:06,119
Speaker 1: come do that work for me now. So the cyanobacteria

527
00:27:06,160 --> 00:27:08,680
Speaker 1: should get all the credit for evolving this incredible ability

528
00:27:08,680 --> 00:27:10,679
Speaker 1: to plants just to like took it over. They're like

529
00:27:10,720 --> 00:27:13,480
Speaker 1: the managers. Or you could look at it the other way, right,

530
00:27:13,520 --> 00:27:17,359
Speaker 1: you could say that cyanobacteria, you know, kind of form

531
00:27:17,440 --> 00:27:20,119
Speaker 1: plants around themselves kind of to do all the hard work.

532
00:27:20,359 --> 00:27:23,960
Speaker 1: They just have to sit back and get a plan. Exactly.

533
00:27:24,520 --> 00:27:26,200
Speaker 1: You can look at anything in two ways, I guess.

534
00:27:26,240 --> 00:27:29,040
Speaker 1: All right, So then we had to wait until everything

535
00:27:29,440 --> 00:27:32,680
Speaker 1: was rusted before we got our third atmosphere. Yeah, it

536
00:27:32,720 --> 00:27:35,920
Speaker 1: wasn't until everything was rusted that the oxygen being produced

537
00:27:35,920 --> 00:27:39,119
Speaker 1: by cyanobacteria and then later also by plants could just

538
00:27:39,160 --> 00:27:41,800
Speaker 1: sort of hang out in the atmosphere that those levels

539
00:27:41,800 --> 00:27:45,040
Speaker 1: could climb to the point where like animals could breathe them.

540
00:27:45,359 --> 00:27:48,040
Speaker 1: And so now we're up to the atmosphere that we

541
00:27:48,119 --> 00:27:51,600
Speaker 1: have today, which is you know, still mostly nitrogen. It's

542
00:27:51,640 --> 00:27:55,399
Speaker 1: like seventy eight percent nitrogen, but a good of our

543
00:27:55,440 --> 00:27:58,360
Speaker 1: atmosphere is O two wow. And it was all made

544
00:27:58,400 --> 00:28:02,840
Speaker 1: by bacteria and plant basically right like before and like

545
00:28:03,080 --> 00:28:05,240
Speaker 1: you know, we didn't get that we made that. Yeah,

546
00:28:05,240 --> 00:28:07,399
Speaker 1: it was made by living creatures. And it took a

547
00:28:07,480 --> 00:28:11,120
Speaker 1: long long time. Right, So if you're imagining, like let's

548
00:28:11,160 --> 00:28:14,320
Speaker 1: go to Mars and produce enough oxygen for the atmosphere

549
00:28:14,359 --> 00:28:16,840
Speaker 1: for us to walk around and breathe, like, it takes

550
00:28:16,840 --> 00:28:19,520
Speaker 1: a long time. Even when you got like jillions of

551
00:28:19,640 --> 00:28:22,920
Speaker 1: tiny little machines pumping out of oxygen, it took millions

552
00:28:22,920 --> 00:28:25,200
Speaker 1: and millions of years. Yeah, it took like four hundred

553
00:28:25,240 --> 00:28:27,359
Speaker 1: million years actually to be precise. And in a way,

554
00:28:27,400 --> 00:28:30,080
Speaker 1: they sort of ruined the planet for themselves a little bit, right,

555
00:28:30,160 --> 00:28:32,120
Speaker 1: or do you think they were co evolving as they

556
00:28:32,119 --> 00:28:35,520
Speaker 1: were changing the atmosphere. They're definitely co evolving. And cyanobacteria

557
00:28:35,560 --> 00:28:38,120
Speaker 1: are still with us. They still produce half of the

558
00:28:38,160 --> 00:28:41,080
Speaker 1: oxygen that we have on the Earth currently, like half

559
00:28:41,080 --> 00:28:42,680
Speaker 1: of it is made by plants and half of it

560
00:28:42,760 --> 00:28:46,640
Speaker 1: is made by cyanobacteria. So they're still around in the oceans. Yeah,

561
00:28:46,680 --> 00:28:48,800
Speaker 1: And so that's how we got our atmosphere and it's

562
00:28:48,840 --> 00:28:51,000
Speaker 1: not I mean it's a lot, obviously, because we have

563
00:28:51,040 --> 00:28:52,840
Speaker 1: a lot to breathe, but in terms of the scale

564
00:28:52,840 --> 00:28:55,640
Speaker 1: of the Earth, it's a really small fliver or a

565
00:28:55,720 --> 00:28:58,840
Speaker 1: small coating of air that we have on the planet. Yeah.

566
00:28:58,880 --> 00:29:02,480
Speaker 1: The whole Earth, of course, is six thousand kilometers in radius.

567
00:29:02,720 --> 00:29:05,680
Speaker 1: The atmosphere where we considerately the atmosphere is you know,

568
00:29:05,800 --> 00:29:08,760
Speaker 1: just like thirty or fifty kilometers high, so it's a

569
00:29:08,920 --> 00:29:12,280
Speaker 1: very very thin ver near It's like a very thin

570
00:29:12,400 --> 00:29:15,000
Speaker 1: coating of water on a billiard ball. Yeah, because like

571
00:29:15,080 --> 00:29:18,680
Speaker 1: what the Earth is, what like ten thousand kilometers in

572
00:29:18,800 --> 00:29:23,480
Speaker 1: radius or something like that kilometers in radius, but only

573
00:29:23,680 --> 00:29:28,040
Speaker 1: the last thirty kilometers are atmosphere. Yeah, And where exactly

574
00:29:28,080 --> 00:29:30,600
Speaker 1: you say the atmosphere and depends really just on where

575
00:29:30,600 --> 00:29:32,800
Speaker 1: you want to say it ends. Some people say it's

576
00:29:32,840 --> 00:29:35,080
Speaker 1: up to a hundred kilometers because you know, it falls

577
00:29:35,120 --> 00:29:37,680
Speaker 1: off very smoothly as you go out into space. But

578
00:29:39,120 --> 00:29:41,240
Speaker 1: of the mass of the atmosphere, like most of the

579
00:29:41,240 --> 00:29:44,480
Speaker 1: stuff in the atmosphere is within the first thirty kilometers.

580
00:29:44,520 --> 00:29:47,840
Speaker 1: The geologists also claim space as geology as well. They're like,

581
00:29:47,920 --> 00:29:51,160
Speaker 1: you know, I just keep going. Their atmosphere is geology,

582
00:29:51,360 --> 00:29:55,640
Speaker 1: space is geology. Galaxies geology. When they say we are

583
00:29:55,720 --> 00:29:57,840
Speaker 1: one with the universe, they mean it literally, like the

584
00:29:57,920 --> 00:30:00,440
Speaker 1: universe is just all part of the Earth. We are one,

585
00:30:00,520 --> 00:30:03,360
Speaker 1: and that one is you got below the surface and

586
00:30:03,400 --> 00:30:05,440
Speaker 1: above the surface, and it's just two parts to the

587
00:30:05,440 --> 00:30:10,000
Speaker 1: whole universe. Or no, it's it's all one big surface geologist.

588
00:30:11,200 --> 00:30:13,520
Speaker 1: But it's actually quite interesting. There are lots of like

589
00:30:13,640 --> 00:30:17,240
Speaker 1: really fascinating layers to the atmosphere. Like you might imagine

590
00:30:17,560 --> 00:30:19,760
Speaker 1: as you go higher up, the air gets thinner and

591
00:30:19,800 --> 00:30:22,280
Speaker 1: thinner and colder and colder until you get out into

592
00:30:22,280 --> 00:30:25,000
Speaker 1: space and it's like super freezing. But actually the temperature

593
00:30:25,040 --> 00:30:27,040
Speaker 1: like varies and it gets hotter and colder and hotter

594
00:30:27,080 --> 00:30:29,360
Speaker 1: and colder as you go up really depending on like

595
00:30:29,400 --> 00:30:32,640
Speaker 1: the composition or did you just get like pockets of stuff, Yeah,

596
00:30:32,680 --> 00:30:35,880
Speaker 1: depending on the composition. They're all these fascinating layers. Like

597
00:30:36,120 --> 00:30:37,920
Speaker 1: as you go up, you know, you go above like

598
00:30:38,040 --> 00:30:40,560
Speaker 1: Mount Everest, for example, things get colder and colder and

599
00:30:40,600 --> 00:30:42,760
Speaker 1: thinner and thinner. But then when you get to like

600
00:30:43,040 --> 00:30:46,320
Speaker 1: this ozone layer, things turn around and start to get hotter.

601
00:30:46,640 --> 00:30:49,720
Speaker 1: As you go past the stratosphere, things actually start to

602
00:30:49,760 --> 00:30:52,240
Speaker 1: get hotter and hotter and hotter, not quite back up

603
00:30:52,280 --> 00:30:55,320
Speaker 1: to like surface levels, but you know, getting kind of

604
00:30:55,360 --> 00:30:58,640
Speaker 1: warm before they turn around again and then get colder

605
00:30:59,000 --> 00:31:01,080
Speaker 1: as you go up through the is a sphere and

606
00:31:01,080 --> 00:31:03,920
Speaker 1: then it turns around again and it actually gets hotter

607
00:31:04,000 --> 00:31:07,480
Speaker 1: and hotter as you go into space, right, Yeah, because

608
00:31:07,480 --> 00:31:09,840
Speaker 1: I guess those are the layers that are absorbing a

609
00:31:09,880 --> 00:31:12,040
Speaker 1: lot of the sunlight. Is that what's happening. They are

610
00:31:12,080 --> 00:31:14,920
Speaker 1: absorbing a lot of the sunlight and they are evaporating, Right,

611
00:31:15,200 --> 00:31:17,240
Speaker 1: what's going to be leaving the Earth? What's going to

612
00:31:17,320 --> 00:31:20,160
Speaker 1: be making it out there to the higher levels are

613
00:31:20,200 --> 00:31:22,720
Speaker 1: the faster moving particles, and so the Earth is sort

614
00:31:22,760 --> 00:31:26,200
Speaker 1: of like differentiating. We are losing our atmosphere constantly. We

615
00:31:26,280 --> 00:31:29,080
Speaker 1: had a whole podcast about that, and primarily we lose

616
00:31:29,120 --> 00:31:32,800
Speaker 1: the hotter atoms, the faster moving ones. So while it's

617
00:31:32,840 --> 00:31:35,040
Speaker 1: not very dense up there, there's not a lot of heat,

618
00:31:35,400 --> 00:31:38,120
Speaker 1: you have faster moving particles, which are the ones that

619
00:31:38,160 --> 00:31:41,440
Speaker 1: are escaping, and so it technically it is hotter. Yeah,

620
00:31:41,440 --> 00:31:43,320
Speaker 1: the hotter ones that are always the first ones to leave,

621
00:31:43,920 --> 00:31:46,920
Speaker 1: for sure. And there's also sort of like radioactive elements

622
00:31:46,920 --> 00:31:49,080
Speaker 1: out there in our atmosphere too, right, Like some pretty

623
00:31:49,200 --> 00:31:52,440
Speaker 1: not saying stuff out there. Yeah, absolutely, one percent of

624
00:31:52,440 --> 00:31:54,880
Speaker 1: our atmosphere is actually are gone. You know, You've got

625
00:31:54,920 --> 00:31:59,560
Speaker 1: like seventy percent nitrogen oxygen, and then one percent are gone,

626
00:32:00,000 --> 00:32:02,880
Speaker 1: which is sort of weird. It's this radiogenic argon forty

627
00:32:03,000 --> 00:32:05,440
Speaker 1: which comes from the decay of potassium forty. And it's

628
00:32:05,440 --> 00:32:08,560
Speaker 1: really interesting actually, because mostly which you have out there

629
00:32:08,600 --> 00:32:12,600
Speaker 1: in the universe, like made by stars is aregon thirty six,

630
00:32:13,080 --> 00:32:15,760
Speaker 1: which is, you know, a different isotope of argon that's

631
00:32:15,840 --> 00:32:18,720
Speaker 1: made in the fusion inside stars. But here on Earth,

632
00:32:18,800 --> 00:32:21,680
Speaker 1: most of the argon in our atmosphere is argon forty,

633
00:32:21,720 --> 00:32:24,680
Speaker 1: which comes from this radioactive decay. And it took people

634
00:32:24,680 --> 00:32:26,360
Speaker 1: a long time to figure out that that's where it

635
00:32:26,400 --> 00:32:28,240
Speaker 1: came from and how it worked, and it was a

636
00:32:28,280 --> 00:32:30,640
Speaker 1: fun puzzle that was solved a few decades ago. And

637
00:32:30,640 --> 00:32:34,160
Speaker 1: there's also some pretty interesting elements like krypton and neon

638
00:32:34,240 --> 00:32:36,720
Speaker 1: and methane, And our atmosphere is not just like nitrogen

639
00:32:36,840 --> 00:32:39,240
Speaker 1: and air and oxygen. Do you remember that everything in

640
00:32:39,280 --> 00:32:43,040
Speaker 1: our solar system came from those same basic soup of ingredients.

641
00:32:43,240 --> 00:32:45,520
Speaker 1: Inside the Sun, of course you have fusion making new

642
00:32:45,520 --> 00:32:48,440
Speaker 1: heavy elements, but outside of the Sun, everything is just

643
00:32:48,480 --> 00:32:50,840
Speaker 1: a mixture of the same elements that went in. Right,

644
00:32:50,880 --> 00:32:54,000
Speaker 1: we have no fusion happening on Earth. All the elemental

645
00:32:54,080 --> 00:32:57,280
Speaker 1: like crypton or neon, or hydrogen or oxygen or all

646
00:32:57,320 --> 00:32:59,720
Speaker 1: the other weird stuff that we have came from fusion

647
00:32:59,760 --> 00:33:03,000
Speaker 1: in side some star somewhere else. Our solar system is

648
00:33:03,000 --> 00:33:06,760
Speaker 1: a population one solar system, which is the third generation

649
00:33:06,840 --> 00:33:10,200
Speaker 1: in our universe. So all of these atoms of oxygen

650
00:33:10,280 --> 00:33:13,240
Speaker 1: and other stuff were formed inside a star billions of

651
00:33:13,280 --> 00:33:16,200
Speaker 1: years ago, which then blew up and led to the

652
00:33:16,200 --> 00:33:19,640
Speaker 1: formation of this dust cloud, which eventually became our solar system.

653
00:33:19,800 --> 00:33:22,600
Speaker 1: That means we're all a little bit cryptonian, right, a

654
00:33:22,640 --> 00:33:24,720
Speaker 1: little bit. Yeah. All of these things that were made

655
00:33:24,720 --> 00:33:27,240
Speaker 1: of that we're breathing, that we're relying on, all came

656
00:33:27,560 --> 00:33:30,640
Speaker 1: from somewhere else, were fused inside a star somewhere, and

657
00:33:30,680 --> 00:33:33,560
Speaker 1: so that's how we got our atmosphere through a lot

658
00:33:33,560 --> 00:33:36,600
Speaker 1: of burpaying by the Earth and surviving some winds and

659
00:33:36,640 --> 00:33:38,760
Speaker 1: a lot of bacteria making it. And that's how we

660
00:33:38,840 --> 00:33:40,840
Speaker 1: got the air that we have today. And thank goodness,

661
00:33:40,880 --> 00:33:43,920
Speaker 1: because it smells pretty good. You could have smelled that, right,

662
00:33:44,400 --> 00:33:46,440
Speaker 1: you guys. We're lucky that the Earth smells good. It

663
00:33:46,560 --> 00:33:49,000
Speaker 1: probably did smell pretty bad for long periods. You know,

664
00:33:49,000 --> 00:33:53,440
Speaker 1: they're probably some pretty stinky times when Earth the stinker scene,

665
00:33:53,840 --> 00:33:56,600
Speaker 1: I think it's called, you know, teenagers they never smelled,

666
00:33:58,000 --> 00:34:01,560
Speaker 1: Introduce them to deodorant, and then things pick up from there.

667
00:34:01,920 --> 00:34:05,200
Speaker 1: All right, let's get into how we know this interesting

668
00:34:05,240 --> 00:34:07,960
Speaker 1: history of our atmosphere and what it could mean for

669
00:34:08,040 --> 00:34:11,480
Speaker 1: the future of Earth and people breathing in it. But first,

670
00:34:11,560 --> 00:34:26,439
Speaker 1: let's take another quick break. All right, we're talking about

671
00:34:26,440 --> 00:34:29,160
Speaker 1: the history of our atmosphere and we're kind of in

672
00:34:29,160 --> 00:34:32,239
Speaker 1: our third atmosphere, is what you're saying, Like we you know,

673
00:34:32,320 --> 00:34:34,239
Speaker 1: we're not in our starter home, we're not in our

674
00:34:34,280 --> 00:34:37,000
Speaker 1: second home. We're like in our our vacation home. Unless

675
00:34:37,040 --> 00:34:39,399
Speaker 1: we've been working on this for a while. We're living

676
00:34:39,440 --> 00:34:42,080
Speaker 1: the dream right now, breathing the dream. We are we

677
00:34:42,160 --> 00:34:44,759
Speaker 1: are And I love hearing those kinds of stories when

678
00:34:44,800 --> 00:34:47,000
Speaker 1: you look around and you don't really know what the

679
00:34:47,040 --> 00:34:49,640
Speaker 1: history of the Earth is, and then you discover through

680
00:34:49,719 --> 00:34:52,920
Speaker 1: various like really subtle clues and awesome detective work that

681
00:34:53,040 --> 00:34:55,440
Speaker 1: things have changed, that the Earth used to be really

682
00:34:55,640 --> 00:34:58,319
Speaker 1: really different. Because you know, your naive assumption is like

683
00:34:58,360 --> 00:34:59,840
Speaker 1: I don't know the earth form that had it to

684
00:34:59,840 --> 00:35:02,480
Speaker 1: have spirits always been like this, that's the simplest story,

685
00:35:02,520 --> 00:35:05,480
Speaker 1: and science always prefers the simplest story. But it's super

686
00:35:05,520 --> 00:35:08,080
Speaker 1: fun when you discover that the story is more complicated

687
00:35:08,080 --> 00:35:10,440
Speaker 1: than it has twists and turns. But you can't just

688
00:35:10,480 --> 00:35:12,920
Speaker 1: like tell that story. You gotta find the clues. You've

689
00:35:12,920 --> 00:35:15,920
Speaker 1: got to discover that story. Yeah, because that's a big question.

690
00:35:15,920 --> 00:35:18,200
Speaker 1: It's like, how do we know all these details? I

691
00:35:18,239 --> 00:35:20,080
Speaker 1: feel like that was a very detailed story of how

692
00:35:20,120 --> 00:35:23,760
Speaker 1: we got our atmosphere, but there was nobody around really

693
00:35:23,840 --> 00:35:26,600
Speaker 1: to sort of measure the oxygen or to see what

694
00:35:26,680 --> 00:35:29,040
Speaker 1: was happening. So how do we know all of these things? Yeah,

695
00:35:29,120 --> 00:35:32,000
Speaker 1: we have to look for clues in the geological record,

696
00:35:32,440 --> 00:35:34,880
Speaker 1: and so the rock record, like rocks that were formed

697
00:35:35,160 --> 00:35:37,759
Speaker 1: five hundred million years ago or a billion years ago

698
00:35:37,920 --> 00:35:41,000
Speaker 1: or two billion years ago, how they formed, and which

699
00:35:41,160 --> 00:35:44,359
Speaker 1: kinds of rocks formed tell us about what atmosphere there

700
00:35:44,480 --> 00:35:47,480
Speaker 1: was around, because some kind of rocks can only form

701
00:35:47,520 --> 00:35:49,760
Speaker 1: in the presence of oxygen, and other kind of rocks

702
00:35:49,960 --> 00:35:52,799
Speaker 1: can only form if there's no oxygen. So as you

703
00:35:52,800 --> 00:35:54,880
Speaker 1: look at the rock layers, you can look like back

704
00:35:54,920 --> 00:35:57,080
Speaker 1: in time and get a sense for like what was

705
00:35:57,120 --> 00:36:00,279
Speaker 1: going on, right, because I guess the rocks are stead

706
00:36:00,280 --> 00:36:03,359
Speaker 1: of changing, right, they're churning, they're flipping over. They sort

707
00:36:03,360 --> 00:36:06,040
Speaker 1: of build up as they're growing, right, So then then

708
00:36:06,040 --> 00:36:08,000
Speaker 1: that's where you get the record. Yeah, if you drive

709
00:36:08,040 --> 00:36:11,680
Speaker 1: through the desert, for example, and you see canyons, etcetera,

710
00:36:11,840 --> 00:36:14,120
Speaker 1: you can see these stripes in the rocks. Right, where

711
00:36:14,120 --> 00:36:17,160
Speaker 1: do those stripes come from? Those are layers of rocks

712
00:36:17,160 --> 00:36:20,000
Speaker 1: that have been laid down over millions and billions of years.

713
00:36:20,000 --> 00:36:22,719
Speaker 1: As you say, the surface is like active stuff is

714
00:36:22,760 --> 00:36:25,640
Speaker 1: coming out from underneath and then creating new layers which

715
00:36:25,680 --> 00:36:28,560
Speaker 1: get laid down and then pushed down, and sometimes those

716
00:36:28,640 --> 00:36:30,600
Speaker 1: layers then break and get pushed back up to the

717
00:36:30,600 --> 00:36:33,320
Speaker 1: surface and revealed, and so we can see that history.

718
00:36:33,440 --> 00:36:36,200
Speaker 1: That's why like dinosaurs are buried in the earth, because

719
00:36:36,239 --> 00:36:39,560
Speaker 1: we're constantly laying down new layers of rock on top

720
00:36:39,600 --> 00:36:42,400
Speaker 1: of the old ones. And so that's super cool because

721
00:36:42,440 --> 00:36:45,120
Speaker 1: it's basically like a snapshot of what was going on

722
00:36:45,120 --> 00:36:47,719
Speaker 1: on the planet back in the day. And as you

723
00:36:47,760 --> 00:36:49,960
Speaker 1: can look at those rocks and see patterns in them,

724
00:36:50,160 --> 00:36:51,879
Speaker 1: then you can get a clue is to like what

725
00:36:51,960 --> 00:36:54,359
Speaker 1: was going on in the atmosphere because all those rocks,

726
00:36:54,360 --> 00:36:57,320
Speaker 1: as we were saying before, interacted with the atmosphere that

727
00:36:57,520 --> 00:36:59,880
Speaker 1: leaves an imprint on the rock basically like if they

728
00:37:00,080 --> 00:37:02,680
Speaker 1: was a lot of oxygen or not, or other kinds

729
00:37:02,719 --> 00:37:05,640
Speaker 1: of gases than the rocks a little different. Yeah, And

730
00:37:05,640 --> 00:37:08,959
Speaker 1: one of the most important clues are these formations called

731
00:37:09,320 --> 00:37:12,120
Speaker 1: banded iron. And these are really beautiful. You should google

732
00:37:12,160 --> 00:37:13,960
Speaker 1: them and check them out because they are basically these

733
00:37:14,040 --> 00:37:17,920
Speaker 1: rocks with these thick red stripes in them, this oxidized

734
00:37:17,920 --> 00:37:20,760
Speaker 1: iron stripes, And that tells us a lot about when

735
00:37:20,800 --> 00:37:25,360
Speaker 1: this oxygen nation event happened, when the cyanobacteria started pumping

736
00:37:25,400 --> 00:37:29,120
Speaker 1: oxygen into the atmosphere, because it started to bind with

737
00:37:29,200 --> 00:37:31,680
Speaker 1: the iron that was out there and get weatherized and

738
00:37:31,760 --> 00:37:35,359
Speaker 1: make these layers and layers of basically rushed inside the

739
00:37:35,360 --> 00:37:38,600
Speaker 1: Earth's atmosphere. So you can look back at these first

740
00:37:38,760 --> 00:37:42,279
Speaker 1: earliest layers of rust and pinpoint when oxygen starts to

741
00:37:42,320 --> 00:37:44,560
Speaker 1: be produced. That makes me think of like a heavy

742
00:37:44,560 --> 00:37:48,839
Speaker 1: metal band or something bad. Iron first rust. There you go,

743
00:37:49,600 --> 00:37:53,239
Speaker 1: red rusted rage. It's super cool because it's sort of

744
00:37:53,280 --> 00:37:57,240
Speaker 1: like rings on a tree because you can see these bands.

745
00:37:57,280 --> 00:38:00,400
Speaker 1: It's not just like, oh, oxygen turned on, start to

746
00:38:00,400 --> 00:38:03,560
Speaker 1: be produced, and then everything after that is just rusted iron.

747
00:38:03,880 --> 00:38:05,960
Speaker 1: You have these bands where it's like rusted iron and

748
00:38:05,960 --> 00:38:08,319
Speaker 1: then none, and then rusted iron and then none, like

749
00:38:08,400 --> 00:38:10,839
Speaker 1: turned on and off and on and off. You can

750
00:38:10,960 --> 00:38:13,040
Speaker 1: be like, oh, look at the earth just burped here

751
00:38:13,239 --> 00:38:16,719
Speaker 1: or just past wind. Yeah, what happens is that this

752
00:38:16,840 --> 00:38:20,400
Speaker 1: oxygen that these bacteria produced is actually poisonous to them, right.

753
00:38:20,480 --> 00:38:24,000
Speaker 1: Cyanobacteria do not like a lot of oxygen, so they

754
00:38:24,040 --> 00:38:27,160
Speaker 1: produced a bunch of oxygen and some cases there was

755
00:38:27,160 --> 00:38:29,719
Speaker 1: like a lot of iron around in the water to

756
00:38:29,800 --> 00:38:32,080
Speaker 1: grab that oxygen and then sink back down to the

757
00:38:32,120 --> 00:38:35,759
Speaker 1: ocean floor and form a band. But sometimes the cyanobacteria

758
00:38:35,840 --> 00:38:39,400
Speaker 1: would produce too much oxygen it couldn't all get breathed

759
00:38:39,440 --> 00:38:42,200
Speaker 1: in by this iron, and then they would poison themselves

760
00:38:42,200 --> 00:38:44,200
Speaker 1: and like kill themselves off, and then they wouldn't be

761
00:38:44,200 --> 00:38:46,600
Speaker 1: producing as much anymore, and so there wouldn't be as

762
00:38:46,680 --> 00:38:49,480
Speaker 1: much iron deposited. But then the conditions were favorable again

763
00:38:49,560 --> 00:38:52,360
Speaker 1: for a cyanobacteria, which would then grow back and produce

764
00:38:52,360 --> 00:38:55,120
Speaker 1: a huge amount of oxygen, which would they create another

765
00:38:55,160 --> 00:38:57,399
Speaker 1: band and sort of this sort of cycle effect where

766
00:38:57,400 --> 00:39:00,640
Speaker 1: they overproduced and kill themselves and then grow. That's kind

767
00:39:00,640 --> 00:39:02,239
Speaker 1: of what's happening to us right now. I mean, we

768
00:39:02,280 --> 00:39:04,239
Speaker 1: are creating so much c O two. Every time we

769
00:39:04,320 --> 00:39:06,239
Speaker 1: breathe out, we create c O two, And so we

770
00:39:06,280 --> 00:39:09,200
Speaker 1: didn't have all these other processes to repleashes the O two,

771
00:39:09,239 --> 00:39:12,520
Speaker 1: we would be basically poisoning ourselves, right, breathing ourselves out

772
00:39:12,520 --> 00:39:14,680
Speaker 1: of a planet. Yeah, we could have a sort of

773
00:39:14,840 --> 00:39:17,920
Speaker 1: similar effect we have, like human civilization builds up and

774
00:39:17,960 --> 00:39:20,160
Speaker 1: then poisons itself with c O two, and then you

775
00:39:20,200 --> 00:39:22,239
Speaker 1: have like a com period on the Earth for a

776
00:39:22,280 --> 00:39:25,920
Speaker 1: million years, while you have like small bands of humanity surviving,

777
00:39:26,280 --> 00:39:30,239
Speaker 1: rebuilding civilization to poison ourselves. Again. I can see your

778
00:39:30,280 --> 00:39:32,440
Speaker 1: brain just writing the sci fi novel there. I think

779
00:39:32,480 --> 00:39:34,440
Speaker 1: I've read that one. But I guess maybe a question

780
00:39:34,560 --> 00:39:37,480
Speaker 1: is like, how do we, you know, correlate that to time.

781
00:39:37,560 --> 00:39:39,799
Speaker 1: Like we can see these bands in the rock, but

782
00:39:39,840 --> 00:39:42,880
Speaker 1: how do we know that band took place or was formed,

783
00:39:43,520 --> 00:39:45,959
Speaker 1: you know, three hundred million years ago or six billion

784
00:39:46,040 --> 00:39:48,359
Speaker 1: years ago? How do we get that calibration of the

785
00:39:48,480 --> 00:39:50,840
Speaker 1: rings in the tree? Oh yeah, great question. It's like

786
00:39:50,840 --> 00:39:53,440
Speaker 1: how do we know the age of any rock? You know?

787
00:39:53,560 --> 00:39:55,760
Speaker 1: And I remember thinking about this as a kid, wondering,

788
00:39:55,760 --> 00:39:58,120
Speaker 1: like what does it even mean the age of a rock?

789
00:39:58,600 --> 00:40:01,520
Speaker 1: You know, because like love is lava, rock and melt

790
00:40:01,600 --> 00:40:03,759
Speaker 1: or flow. It's like asking how old water is. But

791
00:40:03,760 --> 00:40:06,000
Speaker 1: when you talk about the age of a rock, you're

792
00:40:06,040 --> 00:40:09,000
Speaker 1: not talking about like when the chemical elements or even

793
00:40:09,040 --> 00:40:11,880
Speaker 1: the elements inside the rock were formed, because that happened

794
00:40:11,920 --> 00:40:14,680
Speaker 1: inside a star billions of years ago. We're talking about

795
00:40:14,719 --> 00:40:17,839
Speaker 1: like when this crystal was created. Because rocks are a

796
00:40:17,880 --> 00:40:21,440
Speaker 1: solid formation of these elements, right, like cooled together to

797
00:40:21,480 --> 00:40:24,240
Speaker 1: form a solid object. So you can measure that age

798
00:40:24,239 --> 00:40:26,320
Speaker 1: of the rock, which is when did this thing become

799
00:40:26,360 --> 00:40:29,800
Speaker 1: a solid object? How long ago was this thing fluid?

800
00:40:29,960 --> 00:40:32,440
Speaker 1: When did it transition to becoming solid? And you can

801
00:40:32,480 --> 00:40:35,720
Speaker 1: measure that because when that happens, it captures things inside

802
00:40:35,719 --> 00:40:38,400
Speaker 1: of it, these crazy little crystals, and those crystals, some

803
00:40:38,440 --> 00:40:41,600
Speaker 1: of them are radioactive and they like decay very slowly

804
00:40:41,640 --> 00:40:44,120
Speaker 1: over time. You can measure how many of those are

805
00:40:44,440 --> 00:40:47,040
Speaker 1: and calibrate them. And that's when you do to measure

806
00:40:47,080 --> 00:40:50,200
Speaker 1: the age of rocks. I see, like when the rock forms,

807
00:40:50,400 --> 00:40:53,359
Speaker 1: they capture like a taking clock almost inside of them.

808
00:40:53,400 --> 00:40:55,680
Speaker 1: It's sort of similar to carbon dating, which we can

809
00:40:55,800 --> 00:40:59,359
Speaker 1: use to age like things that were once alive because

810
00:40:59,400 --> 00:41:02,319
Speaker 1: they have certain ratios of carbon in them. But here

811
00:41:02,360 --> 00:41:04,759
Speaker 1: we're talking about things that are much much older. So

812
00:41:04,800 --> 00:41:08,000
Speaker 1: we use these radiometric dating methods based on the natural

813
00:41:08,120 --> 00:41:12,120
Speaker 1: radioactive decay of things like potassium and carbon to date

814
00:41:12,320 --> 00:41:17,360
Speaker 1: these ancient ancient events. I would different rocks. That's a

815
00:41:17,520 --> 00:41:20,000
Speaker 1: terrible joke. I apologist for them. So yeah, so that's

816
00:41:20,000 --> 00:41:23,640
Speaker 1: how we know then, how the history of our atmosphere. Yeah,

817
00:41:23,640 --> 00:41:26,000
Speaker 1: because we can look at this record and so that's

818
00:41:26,040 --> 00:41:29,440
Speaker 1: one piece of evidence is these banded iron formations. You

819
00:41:29,440 --> 00:41:32,800
Speaker 1: know this that's a big influence on like our civilization

820
00:41:33,239 --> 00:41:36,759
Speaker 1: because Detroit, for example, is in a location where there

821
00:41:36,840 --> 00:41:40,440
Speaker 1: used to be an ocean with huge colonies of cyanobacteria

822
00:41:40,719 --> 00:41:44,920
Speaker 1: depositing lots of bands of iron and so like that's

823
00:41:44,960 --> 00:41:48,480
Speaker 1: why a huge fraction of the steel deposits available on

824
00:41:48,560 --> 00:41:50,680
Speaker 1: Earth are like near Detroit, and that's why we have

825
00:41:50,760 --> 00:41:54,719
Speaker 1: a car industry near Detroit because of this cyanobacteria. So

826
00:41:54,800 --> 00:41:58,120
Speaker 1: I love these like connections from the ancient times back

827
00:41:58,160 --> 00:42:01,400
Speaker 1: to like you know, modern zivilization and even politics. They

828
00:42:01,400 --> 00:42:04,439
Speaker 1: always talk about the rust belt, right exactly, they should

829
00:42:04,480 --> 00:42:07,799
Speaker 1: be talking about the cyanobacteria belt. Really, yeah, nobody wants

830
00:42:07,840 --> 00:42:11,000
Speaker 1: to be in that political group. But this also lines

831
00:42:11,080 --> 00:42:14,080
Speaker 1: up with other pieces of evidence. Again, we look into

832
00:42:14,080 --> 00:42:17,239
Speaker 1: the record to see what could happen with oxygen and

833
00:42:17,280 --> 00:42:20,160
Speaker 1: what could happen without oxygen. And there are other minerals

834
00:42:20,239 --> 00:42:23,239
Speaker 1: like pyrite, this thing called fools gold, which can only

835
00:42:23,280 --> 00:42:26,440
Speaker 1: form when there's no oxygen in the atmosphere. It's it's

836
00:42:26,440 --> 00:42:29,160
Speaker 1: oxygen around and the elements that would otherwise make pyrite

837
00:42:29,280 --> 00:42:32,120
Speaker 1: tend to make other things instead. And so you can say, like, oh,

838
00:42:32,160 --> 00:42:36,080
Speaker 1: pyrite was only created until about a certain date several

839
00:42:36,080 --> 00:42:38,640
Speaker 1: billion years ago. So that's another clue. And I imagine

840
00:42:38,680 --> 00:42:40,799
Speaker 1: also there's a lot of it is sort of theoretical,

841
00:42:40,920 --> 00:42:43,439
Speaker 1: kind of based on models of how the Earth form, right,

842
00:42:43,520 --> 00:42:46,320
Speaker 1: for example, we can only go back so much. But

843
00:42:46,440 --> 00:42:49,799
Speaker 1: these methods, like when you're talking about before, like you know,

844
00:42:49,800 --> 00:42:52,920
Speaker 1: our early or first atmosphere getting blown away by the

845
00:42:53,040 --> 00:42:55,640
Speaker 1: solar wind. That's you know, we don't have evidence for that,

846
00:42:55,719 --> 00:42:58,000
Speaker 1: but you know, from what we know how the planets

847
00:42:58,040 --> 00:43:00,600
Speaker 1: get formed, that's probably what happened and we know the

848
00:43:00,640 --> 00:43:02,880
Speaker 1: solar wind exists. We can measure the solar wind, and

849
00:43:02,920 --> 00:43:05,640
Speaker 1: so we can model what would happen if we didn't

850
00:43:05,680 --> 00:43:07,759
Speaker 1: have a magnetic field. So yeah, well there's a lot

851
00:43:07,800 --> 00:43:09,799
Speaker 1: of things we can do to validate those models. But

852
00:43:09,880 --> 00:43:13,040
Speaker 1: absolutely there's modeling going on all over the place in

853
00:43:13,080 --> 00:43:15,400
Speaker 1: all of these studies. And you know, we try to

854
00:43:15,400 --> 00:43:17,239
Speaker 1: make assumptions and then they would trying to find ways

855
00:43:17,280 --> 00:43:20,160
Speaker 1: to check them and to validate those assumptions. Absolutely. You know,

856
00:43:20,200 --> 00:43:22,319
Speaker 1: another thing we do is we think about, like how

857
00:43:22,440 --> 00:43:25,880
Speaker 1: life could have evolved. A lot of the basic chemical

858
00:43:25,920 --> 00:43:29,319
Speaker 1: building blocks of life couldn't have formed if we had

859
00:43:29,360 --> 00:43:33,000
Speaker 1: oxygen in the atmosphere, right, So life produced oxygen, but

860
00:43:33,080 --> 00:43:36,400
Speaker 1: in lots of cases it's inhibited by the presence of oxygen.

861
00:43:36,560 --> 00:43:38,400
Speaker 1: That kind of life that me and you are, this

862
00:43:38,640 --> 00:43:41,680
Speaker 1: aerobic kind of life that relies on oxygen, is fairly

863
00:43:41,800 --> 00:43:45,080
Speaker 1: late showing up in the evolutionary record. And so if

864
00:43:45,160 --> 00:43:48,759
Speaker 1: we had had oxygen, like outgassed by those volcanoes, we

865
00:43:48,840 --> 00:43:52,440
Speaker 1: might not have formed life, right because the earliest life,

866
00:43:52,760 --> 00:43:56,960
Speaker 1: like our ancestors, were anaerobic, right, they didn't like oxygen. Yeah,

867
00:43:57,000 --> 00:43:59,880
Speaker 1: they're poisoned by oxygen, and not just the life itself,

868
00:44:00,080 --> 00:44:02,240
Speaker 1: like the chemical building blocks, a lot of those amino

869
00:44:02,320 --> 00:44:04,960
Speaker 1: acids that they need to just like bump together in

870
00:44:04,960 --> 00:44:07,799
Speaker 1: a weird way in the primordial soup. Those couldn't have

871
00:44:07,920 --> 00:44:10,359
Speaker 1: formed if there was oxygen, because oxygen is just like

872
00:44:10,680 --> 00:44:13,279
Speaker 1: so excited. It bonds to everything and it prevents other

873
00:44:13,320 --> 00:44:16,200
Speaker 1: things from happening. So if we've had oxygen around, we

874
00:44:16,239 --> 00:44:18,800
Speaker 1: could have made those building blocks, and maybe life itself

875
00:44:18,840 --> 00:44:22,520
Speaker 1: wouldn't have started sort of crazy. So it's a good

876
00:44:22,560 --> 00:44:25,399
Speaker 1: thing we didn't have oxygen then, but it's a good

877
00:44:25,400 --> 00:44:28,279
Speaker 1: thing that we have it now, Yes, exactly. And it's

878
00:44:28,280 --> 00:44:31,279
Speaker 1: like such a delicate balance, right. We needed oxygen to

879
00:44:31,320 --> 00:44:33,560
Speaker 1: not be around, and then we needed these other life

880
00:44:33,560 --> 00:44:35,480
Speaker 1: to exist for a while, and then to produce a

881
00:44:35,520 --> 00:44:37,799
Speaker 1: bunch of oxygen so that we could evolve. It's a

882
00:44:37,840 --> 00:44:42,239
Speaker 1: crazy story, right, but I guess it's all one constant evolution. Right.

883
00:44:42,280 --> 00:44:44,560
Speaker 1: You can't just ask, like, we wouldn't be here if

884
00:44:44,560 --> 00:44:47,680
Speaker 1: we didn't have oxygen, but maybe some other anaerobic beans

885
00:44:47,680 --> 00:44:51,000
Speaker 1: would be here having a podcast breathing out less hot

886
00:44:51,000 --> 00:44:55,080
Speaker 1: air than we are, at least less mellie air. Maybe. Yeah, absolutely,

887
00:44:55,280 --> 00:44:57,719
Speaker 1: it's just that our particular path relied on all of

888
00:44:57,719 --> 00:45:00,919
Speaker 1: these things happened in a particular order. Really, if things

889
00:45:00,920 --> 00:45:03,160
Speaker 1: have been different, you know, you could have evolved life

890
00:45:03,160 --> 00:45:05,560
Speaker 1: in lots of other different ways. Well, I guess I'm

891
00:45:05,560 --> 00:45:08,359
Speaker 1: glad that it worked out this way. And it's good

892
00:45:08,360 --> 00:45:11,120
Speaker 1: to know these things also because not just because maybe

893
00:45:11,200 --> 00:45:14,120
Speaker 1: we want to change other planets, but we may also

894
00:45:14,200 --> 00:45:18,120
Speaker 1: want to find other planets like ours that have an atmosphere,

895
00:45:18,480 --> 00:45:21,160
Speaker 1: and so knowing these things might help us find or

896
00:45:21,239 --> 00:45:24,960
Speaker 1: maybe our second or fourth home or retirement home maybe

897
00:45:24,960 --> 00:45:28,400
Speaker 1: for humanity. Yeah, we are just now able to probe

898
00:45:28,440 --> 00:45:32,239
Speaker 1: the atmospheres of planets around other stars by seeing how

899
00:45:32,320 --> 00:45:35,879
Speaker 1: light passes through them as they block their stars. And

900
00:45:36,080 --> 00:45:38,800
Speaker 1: understanding how a planet forms its atmosphere and how the

901
00:45:38,880 --> 00:45:42,120
Speaker 1: atmosphere evolves is really crucial to answering the question like

902
00:45:42,320 --> 00:45:45,160
Speaker 1: is there one out there we could land on? Because

903
00:45:45,200 --> 00:45:47,439
Speaker 1: there might be a planet out there in the habitable zone,

904
00:45:47,520 --> 00:45:50,640
Speaker 1: meaning it's like warm enough to melt water on the surface,

905
00:45:50,920 --> 00:45:53,080
Speaker 1: but there might not be an atmosphere, and that's not

906
00:45:53,280 --> 00:45:56,680
Speaker 1: terribly useful because you can take millions and millions of years.

907
00:45:57,000 --> 00:46:00,520
Speaker 1: Even if you like plants cyanobacteria in the water on

908
00:46:00,560 --> 00:46:03,600
Speaker 1: an alien planet to produce enough oxygen. So it's a

909
00:46:03,640 --> 00:46:06,880
Speaker 1: really interesting question, like how long does this take? Is

910
00:46:06,920 --> 00:46:09,880
Speaker 1: it unusual on Earth? Could happen faster on other planets?

911
00:46:09,960 --> 00:46:12,719
Speaker 1: Is it already happening on other planets out there right

912
00:46:12,719 --> 00:46:15,920
Speaker 1: now with primitive life producing oxygen. It's a really interesting

913
00:46:15,920 --> 00:46:18,080
Speaker 1: and deep question and one that might be really important

914
00:46:18,120 --> 00:46:20,279
Speaker 1: for the future of humanity. Yeah, you don't want to

915
00:46:20,480 --> 00:46:23,200
Speaker 1: pack up all of your things move halfway across the

916
00:46:23,239 --> 00:46:26,359
Speaker 1: gaxy and then when you get there, that wouldn't be good.

917
00:46:26,520 --> 00:46:29,479
Speaker 1: And also for our neighbors. You know, Elon Musk talks

918
00:46:29,520 --> 00:46:31,560
Speaker 1: a lot about moving to Mars and making it a

919
00:46:31,600 --> 00:46:33,799
Speaker 1: second home for humanity, but it's going to take a

920
00:46:33,840 --> 00:46:36,440
Speaker 1: long time before you can walk on the surface of

921
00:46:36,480 --> 00:46:39,440
Speaker 1: Mars and like take a deep breath and survive, not

922
00:46:39,520 --> 00:46:42,040
Speaker 1: to mention even enjoy it. All right, Well, it kind

923
00:46:42,080 --> 00:46:43,799
Speaker 1: of makes you grateful for the air that we have,

924
00:46:43,840 --> 00:46:46,080
Speaker 1: because you know, this is kind of the only thing

925
00:46:46,080 --> 00:46:48,279
Speaker 1: we have to breathe and the only place in our

926
00:46:48,360 --> 00:46:50,440
Speaker 1: Solar System and maybe in our galaxy that we know

927
00:46:50,480 --> 00:46:54,240
Speaker 1: of right now where we could comfortably walk around outside

928
00:46:54,360 --> 00:46:56,960
Speaker 1: and breathe the air. I'm very grateful. I'm full of it.

929
00:46:57,040 --> 00:46:58,960
Speaker 1: You're full of hot air and cold air and all

930
00:46:59,000 --> 00:47:01,120
Speaker 1: the air. I'm putting them all on at the same time,

931
00:47:01,880 --> 00:47:05,560
Speaker 1: and burping them and doing other contributions to the air

932
00:47:05,680 --> 00:47:08,480
Speaker 1: all at the same time, and speaking Icelandic very badly

933
00:47:08,600 --> 00:47:12,279
Speaker 1: into a microphone for other people to hear. All right, Well,

934
00:47:12,320 --> 00:47:15,400
Speaker 1: that's the history of our atmosphere and we hope you

935
00:47:15,480 --> 00:47:18,080
Speaker 1: enjoyed that. Thanks for joining us, See you next time.

936
00:47:25,800 --> 00:47:28,640
Speaker 1: Thanks for listening, and remember that Daniel and Jorge explained.

937
00:47:28,680 --> 00:47:31,600
Speaker 1: The Universe is a production of I Heart Radio or

938
00:47:31,719 --> 00:47:34,640
Speaker 1: more podcast for my heart Radio, visit the I Heart

939
00:47:34,719 --> 00:47:38,319
Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your

940
00:47:38,360 --> 00:47:44,720
Speaker 1: favorite shows. Ye