Speaker 1: Hello friends. One of my favorite parts of co hosting
Speaker 1: this podcast with Daniel is that it's given me the
Speaker 1: chance to meet and interact with a bunch of you.
Speaker 1: I've really enjoyed learning about your backgrounds, your interests, and
Speaker 1: some of you have cracked me up in some of
Speaker 1: the emails. You're a funny bunch, and in particular, I
Speaker 1: love getting your questions. Y'all ask some incredible questions and
Speaker 1: often there are questions I had never thought about before,
Speaker 1: and Daniel and I love that we get to find
Speaker 1: answers to questions that keep you up at night. So
Speaker 1: today Daniel and I are going to tackle three questions
Speaker 1: that we've received from listeners. And we take the responsibility
Speaker 1: of finding answers to your questions quite seriously. So after
Speaker 1: we have an answer to these questions recorded, we check
Speaker 1: back with the listeners to see how we did with
Speaker 1: the answers. Essentially, we let you all grade us, and
Speaker 1: if we fail to give a clear answer, we're gonna
Speaker 1: try again, and in this way you all can help
Speaker 1: us learn how to explain things even more clearly. So
Speaker 1: thank you. If you want to send us a question,
Speaker 1: you can either join us on our discord channel or
Speaker 1: you can send us an email at questions at Daniel
Speaker 1: and Kelly dot org. We hope to hear from you,
Speaker 1: and welcome to Daniel and Kelly's extraordinary universe.
Speaker 2: I'm Daniel, I'm the particle physicist, and I love getting
Speaker 2: your questions.
Speaker 1: I'm Kelly Wienersmith. I study parasites, and as you already
Speaker 1: know from the opening, I love getting your questions too.
Speaker 2: Do your kids ask you science questions you can't answer? Kelly?
Speaker 1: Oh yeah, So my daughter asked me a good science
Speaker 1: question that I sent to you the other day, so
Speaker 1: I know the right people. And every once in a
Speaker 1: while she will ask a question that's like at a
Speaker 1: very deep level of why, and I won't know the
Speaker 1: answer and she'll stump me sometimes. But she also doesn't
Speaker 1: like talking to me about biology too much because she knows,
Speaker 1: which is such a bummer. But uh, is that.
Speaker 2: Because your answers are too long? Is that why?
Speaker 1: That's exactly why it is. That's exact exactly why we
Speaker 1: have Yeah, oh yeah. Do your kids ask you questions
Speaker 1: you can't answer?
Speaker 2: They do sometimes ask me questions I can't answer, but
Speaker 2: they always stopped me after a few sentences and Hazel's
Speaker 2: favorite line is like, I didn't ask for a college lecture.
Speaker 1: I mean, your dad's a college professor. That's what you're
Speaker 1: going to get.
Speaker 2: And your mom too, Yeah, that's right, what do you expect?
Speaker 2: But it's fun. I love their questions, and I love
Speaker 2: the challenge of trying to answer it within that teenager
Speaker 2: attention span of like six seconds.
Speaker 1: It certainly forces you to be succinct and clear. It's good,
Speaker 1: it's good fortice, yes exactly, but it's not naturally how
Speaker 1: I roll. But that's okay because with at least twenty
Speaker 1: minutes to answer each one of these questions, so we
Speaker 1: can go ahead and get into a nice bit of detail.
Speaker 1: Our first question is you know exactly the kinds of
Speaker 1: amazing questions that I hadn't thought of ahead of time,
Speaker 1: but I love getting a chance to think about. So
Speaker 1: the first one is about you know, soil on Mars
Speaker 1: and what makes soil? And I just thought this was
Speaker 1: such a fantastic question, but I didn't know the answer.
Speaker 1: And so it's also a great chance to bring a
Speaker 1: friend on the show.
Speaker 2: Hello, Daniel and Kelly.
Speaker 3: After two Mars episodes, a question or two popped in
Speaker 3: my brain Mars does not have soil now, but if
Speaker 3: that was live a long time ago on Mars, could
Speaker 3: there be soiled deeper down in the ground. Also, if
Speaker 3: they used to be like on Mars, could that have
Speaker 3: created oil deep on the ground. Can single cells produce
Speaker 3: oil or do we need at least bigger life than that?
Speaker 3: Thank you for the podcast, Kind to your guards.
Speaker 1: Yost Okay, So this sounds like a geology question, and
Speaker 1: lucky for me, I have a geology friend. He was
Speaker 1: my poraranteine buddy in the pandemic. So we're bringing onto
Speaker 1: the show Callen Bentley, who's an associate professor of geology
Speaker 1: at Piedmont Virginia Community College and he's co author of
Speaker 1: the free online textbook Historical Geology. Callen, what's up?
Speaker 4: Hey, thanks for having me. I'm glad to be here.
Speaker 1: We're happy to have you here. So I read this
Speaker 1: question and I remembered that I had a conversation with
Speaker 1: you once about what's the difference between regolith and soil?
Speaker 1: And I think I remember you just sighed and walked
Speaker 1: away or something. It was something like my sense was that, oh,
Speaker 1: these it's just jargon, But so what can you tell
Speaker 1: me what is the difference between soil and just dirt
Speaker 1: and regolith.
Speaker 4: Yeah, so dirt doesn't really have a scientific meaning, but
Speaker 4: regolith does and soil does. And the difference between them
Speaker 4: is that soil has organic matter in it, which we
Speaker 4: call humous here on this planet, not to.
Speaker 2: Be confused with the delicious dip with the heeny in it.
Speaker 4: That's right, That is hummus, and there is a difference
Speaker 4: of one m here on Earth. Humus gets added from
Speaker 4: the top. So basically, like this time of year, the
Speaker 4: leaves are dropping off of many of the trees in
Speaker 4: the northern hemisphere, and that's basically a rich source of
Speaker 4: organic matter and that drops onto the soil and those
Speaker 4: leaves fall apart or they get tugged underground by earthworms
Speaker 4: and basically get mixed in with the rock, fragments and
Speaker 4: mineral grains that make up the other sort of solid
Speaker 4: bulk of the soil. It's important to realize that soil
Speaker 4: actually consists of, you know, solid stuff, but also a
Speaker 4: lot of empty space which can be filled with either
Speaker 4: air or water depending on whether you're in a drought
Speaker 4: or it rained recently, or how deep you are on
Speaker 4: the soil. So you know, if you went and looked
Speaker 4: at the Apollo astronauts' footprints on the Moon, those are
Speaker 4: in regolith because there's no organic matter on the Moon.
Speaker 4: We don't know about, you know, sort of thet of
Speaker 4: Mars as well as we know about the Moon, because
Speaker 4: we haven't been there and picked up samples and you
Speaker 4: know it brought them back, and you know, we've done
Speaker 4: a few sort of remote experiments. But the sort of
Speaker 4: mechanism of folding organic material into the you know, putative
Speaker 4: Martian soil would seem to be lacking and so at
Speaker 4: least in the present day now if it existed in
Speaker 4: the past. You know, that's I suppose a possibility if
Speaker 4: Mars had a thicker atmosphere in the past and a
Speaker 4: more pronounced greenhouse effect, you know, perhaps there was life
Speaker 4: there in the terrestrial realm at that time that could
Speaker 4: produce organic material and add it to the regulith and
Speaker 4: turn it into soil. And it is indeed possible, as
Speaker 4: the listener asks, that those old soils could be buried
Speaker 4: under subsequent sedimentary layers, perhaps with zero organic content. We
Speaker 4: have examples of buried soils here on Earth. We call
Speaker 4: them paleo sols, and there are a lot of examples
Speaker 4: of them. They have various characteristics that are signatures of
Speaker 4: the conditions under which they formed, just like sedimentary rocks
Speaker 4: contain signatures of the circumstances under which the sediments accumulated.
Speaker 2: Do you make soil in the surface and then it
Speaker 2: can get buried And so you're saying, if you had
Speaker 2: life a long time ago, you would have made soil,
Speaker 2: and then life all died out, you continue to make layers,
Speaker 2: and that buries the old soil into is that paleosoil.
Speaker 4: Paleo soal? So they drop the eye. Yeah, soils are
Speaker 4: a little bit weird. They call the soils themselves by
Speaker 4: these names that all end in sols, like arit asols
Speaker 4: and gelisols, and I don't know a bunch of them.
Speaker 4: Soil scientists are really into classifying things. They've like organized
Speaker 4: all of the planet Earth's soils into like nineteen thousand
Speaker 4: soil orders or soil series, and then those are grouped
Speaker 4: into like a dozen or maybe fourteen soil orders. Honestly,
Speaker 4: it's not my area of expertise. The main thing that
Speaker 4: seems to be a driver for my sort of basic
Speaker 4: level understanding is that the climate really controls what sort
Speaker 4: of soil you get in a given area. So soils
Speaker 4: and deserts tend to be really jacked up in terms
Speaker 4: of their evaporate mineral content because water gets wicked through them,
Speaker 4: carrying material in solution, and then that gets precipitated as
Speaker 4: the water goes into the atmosphere, So they tend to
Speaker 4: be very hard and calcareous. Soils in the tropics tend
Speaker 4: to be really clay rich because the most common mineral
Speaker 4: in the crust of the planet, feltzbar rots underwarm, wet
Speaker 4: conditions and it makes clay, so you get these bright
Speaker 4: red iron oxide stained clay rich tropical soils.
Speaker 1: So Mars has red soils like that. Is there any
Speaker 1: similarity there or am I just reach in.
Speaker 4: There's definitely oxidized iron in the what I would call
Speaker 4: regolith and sedimentary rocks of Mars. So yeah, that's a
Speaker 4: similarity that the iron there reacted with oxygen. And under
Speaker 4: what circumstances that occurred. I couldn't tell you whether that
Speaker 4: was in the open air, you know, whether it was submarine,
Speaker 4: or whether it was you know, in a fresh water system,
Speaker 4: or whether it was underground due to ground water. You know,
Speaker 4: there's a lot of possibilities there.
Speaker 2: How much do we know about the surface of Mars.
Speaker 2: I mean, I know we've had rovers there for decades
Speaker 2: and they like pick up rocks and they drill into them.
Speaker 2: But half far like down, have we dug into Mars?
Speaker 4: Not far? Yeah, there was an attempt a few years
Speaker 4: back to you know, basically drill the deepest hole yet
Speaker 4: dug on Mars in the service of installing a seismometer
Speaker 4: so we could listen for marsquakes.
Speaker 2: Love that word marsquakes.
Speaker 4: Yeah, And I don't think it got very far. I
Speaker 4: think it got stuck, and so it was sort of
Speaker 4: an abortive kind of thing. Kelly's nodding, so maybe she's
Speaker 4: more familiar with the history of that.
Speaker 1: I think it was more than one problem one. I
Speaker 1: think things were more compact than they had expected them
Speaker 1: to be, so it's harder to get through. And then
Speaker 1: also it was having trouble gripping and staying in one spot.
Speaker 1: It got only a fraction of the goal of the
Speaker 1: depth that it was shooting for. It's just hard to
Speaker 1: work in space.
Speaker 2: My Wikipedia research tells me that the deepest hole on
Speaker 2: Mars is nine and millimeters deep, which is not very impressive.
Speaker 1: Oh man, So if there's soul on Mars, probably it's
Speaker 1: just bacteria. Uh that that's adding the like lify component
Speaker 1: to it. Is there anywhere? There's probably nowhere on Earth
Speaker 1: where it would be just like that. Probably anywhere else
Speaker 1: you'd also find like nematods and stuff.
Speaker 4: Well, yeah, not anymore. There certainly would have been paleo
Speaker 4: environments on Earth when it would have just been microbial,
Speaker 4: and those would have lasted for a very long time
Speaker 4: for you know, the first several billion years of Earth history.
Speaker 4: You know, some of those microbes would be prokaryotic of course,
Speaker 4: and then eventually you carry out show up as well.
Speaker 4: But yeah, probably it would be unicellular, if anything big
Speaker 4: If could.
Speaker 1: Having just unicellular organisms result in oil? Or do you
Speaker 1: need bigger stuff to get oil?
Speaker 4: Oh wait, wait, we're going into oil now. I thought
Speaker 4: we were talking about soil. So have we dropped the.
Speaker 2: S You dropped the eye and went to soils, and
Speaker 2: now we're going to drop the S and good oils?
Speaker 4: Yeah, okay, So with with oil the story is a
Speaker 4: little different. It's a little more complicated. So when I
Speaker 4: think of soils, I am thinking of terrestrial regalith with
Speaker 4: organic material being added from the top and then gradually
Speaker 4: getting mixed in, but the organic content would decrease the
Speaker 4: deeper you.
Speaker 2: Go, Holnd did just say terrestrial regolith? That means on Earth?
Speaker 4: Yeah, thank you so much for asking that clarifying question
Speaker 4: about the words I'm using. What I meant was not underwater,
Speaker 4: not in the ocean, So I meant on the land,
Speaker 4: all right. So you know, my default setting would not
Speaker 4: be to call marine sediments by the name soil. I
Speaker 4: would call them sediments, and they might have a high
Speaker 4: organic content or they might not. But that is not
Speaker 4: what I'm saying when I'm talking about soil. So I'm
Speaker 4: talking about land based settings. So that's what I mean
Speaker 4: by terrestrial.
Speaker 1: But you said terrestrial realith. You use the R word.
Speaker 4: Originally it would have been regalith, right, and then eventually,
Speaker 4: sometime in Earth history it started becoming soil through the
Speaker 4: addition of this magical ingredient of humans.
Speaker 1: This cleared up an argument Daniel and I had.
Speaker 2: In the past.
Speaker 1: Thank you.
Speaker 2: It turns out you turn regolith into soil just by
Speaker 2: adding hummus or hemus.
Speaker 4: You could add, yes, you could do the job with
Speaker 4: hummus or other forms of humous.
Speaker 2: Bhemi is like magic, really, it sort of life giving.
Speaker 4: The scientific community argues at meetings like a geological meetings
Speaker 4: like the Geological Society of America. There are periodically sessions
Speaker 4: about the terrestrial biosphere during the Cambrian and what they're
Speaker 4: not saying there is the biosphere on Earth. They're talking
Speaker 4: about the biosphere on land. So we have a much
Speaker 4: better geologic record about what was happening in the oceans
Speaker 4: because that's a place where sediments tend to get deposited
Speaker 4: and tend not to get eroded, whereas the land is
Speaker 4: a place where sediments tend to get eroded and tend
Speaker 4: not to get deposited, at least in the long term sense.
Speaker 4: We do have terrestrial here again, I mean land deposits
Speaker 4: of sedimentary rocks, but they are far less common, fewer,
Speaker 4: and further between than marine eediments.
Speaker 1: We were going to get back to oils, So.
Speaker 4: That's basically what I was saying for soils, Okay, And yeah,
Speaker 4: basically we don't know when the humans started getting added.
Speaker 4: People argue about that, and they look at various you know, biotracers,
Speaker 4: geochemical signals, things, like that. As far as oil, oil
Speaker 4: is a liquid hydrocarbon cocktail that is formed due to
Speaker 4: cooking algae, cooking phytoplankton. All right, so I'm using algae
Speaker 4: here in the most inclusive sense. But basically, you know
Speaker 4: phytoplankton photosynthesizing in the upper sunlit portions of bodies of water,
Speaker 4: usually the ocean, but potentially also you know large lakes
Speaker 4: and things like that. They capture energy from the sun
Speaker 4: doing photosynthesis, they lock that up in their organic molecules.
Speaker 4: Then they kick the bucket and they die, and if
Speaker 4: they avoid getting eaten, then they fall down and their
Speaker 4: little dead bodies accumulate on the bottom of that body
Speaker 4: of water. They are likely to accumulate there if there's
Speaker 4: not a lot of things that are grazing them trying
Speaker 4: to eat them, and oxygen levels are relatively low. So
Speaker 4: if you bury this organic rich stuff and you warm
Speaker 4: it up, then you can cause chemical reactions to take
Speaker 4: place that produce the stuff that we call oil and
Speaker 4: the stuff that we call natural gas, which again is
Speaker 4: a cocktail of a bunch of different ingredients. Button in
Speaker 4: the case of natural gas, they are in the gas state,
Speaker 4: not in the liquid state, So with accumulating that phytoplankton
Speaker 4: here on Earth. You know, there's certain conditions that we
Speaker 4: need to kind of go through to get that stuff
Speaker 4: and get it down to the bottom of the ocean,
Speaker 4: and then it has to be buried, and then it
Speaker 4: has to warm up to the right temperature. So before
Speaker 4: we started our podcast today, I made a cup of coffee,
Speaker 4: and that's about the right temperature that you need to
Speaker 4: warm up your dead phytoplankton in order to get them
Speaker 4: to produce oil. If you don't heat them up enough,
Speaker 4: they don't make the oil. And if you heat them
Speaker 4: up too much, it basically it reacts away and makes
Speaker 4: other compounds that are not capable of flowing and being
Speaker 4: pumped out of the ground. So the happy place for
Speaker 4: oil production is around one hundred degrees celsius. Okay, the
Speaker 4: temperature of an espresso.
Speaker 2: This sounds kind of complicated and not so easy to arrange.
Speaker 2: How is it that we have so much oil on Earth?
Speaker 4: Well, we would have more if it wasn't sidaran complicated,
Speaker 4: and you know, we have some, but we don't have
Speaker 4: an infinite amount. So it's these circumstances might sound really
Speaker 4: far fetched and unlikely to occur, but they have occurred,
Speaker 4: and if they hadn't, you know, we would probably be
Speaker 4: living very very different lives.
Speaker 1: So Mars used to be warmer because it had flowing
Speaker 1: water at one point was it that warm.
Speaker 4: So what I am talking about is not the temperature
Speaker 4: at the surface. And if if the temperature at the
Speaker 4: surface was one hundred degrees c, you wouldn't have flowing water,
Speaker 4: you'd have you know, water vapor right or you know,
Speaker 4: the transition between those. What I'm talking about is burial conditions.
Speaker 4: So deep in the earth, and you know, there's usually
Speaker 4: some amount of overburden, some amount of pressure of overlying
Speaker 4: sedimentary layers weighing down on this sort of pressure cooker
Speaker 4: where these phytoplankton are getting simmered, and that's the right
Speaker 4: condition to produce the oil. Then if that is up
Speaker 4: near the surface of the earth, you're on Earth. If
Speaker 4: it flows out at the surface, then a couple of
Speaker 4: things happen. One is it can devolatilize, and so that
Speaker 4: will release the stuff that kind of keeps it low viscosity,
Speaker 4: and it tends to get more gooey and sticky and
Speaker 4: tar like at that point, and ultimately the high levels
Speaker 4: of oxygen in ER's atmosphere will react with those leaking
Speaker 4: petroleum deposits on the surface, and ultimately, you know, they
Speaker 4: will release their energy through reaction with oxygen, but in
Speaker 4: a way that's not conducive to humans capturing that energy
Speaker 4: and putting it to work. So there are places where
Speaker 4: that occurs, and you you know probably have heard of
Speaker 4: the LaBrea tar pits or the beaches at Carbon Drhea
Speaker 4: in California. Those are places where petroleum is actively leaking
Speaker 4: out onto Earth's surface naturally, all right, But in order
Speaker 4: to utilize oil, what we do is we try and
Speaker 4: find places where that hasn't occurred, but where it has
Speaker 4: pooled in the subsurface. So, Daniel, if you thought it
Speaker 4: was complicated before, there's actually another step, which is that
Speaker 4: we need to take the oil out of these nice,
Speaker 4: warm source rocks and then move it into some place
Speaker 4: where it will pull in an accessible sort of setting.
Speaker 4: And so you know, ideally that would be some sort
Speaker 4: of subterranean trap. We call them, and one of the
Speaker 4: most common ones is a fold in the rock layers
Speaker 4: that goes up in the middle. It's so called anticline.
Speaker 4: And if you have a sort of sandwich of less
Speaker 4: permeable and more permeable and less permeable rock layers such
Speaker 4: as shale sandstone shale. Then that provides a nice little
Speaker 4: and then you fold it into like a rainbow shape.
Speaker 4: The sandstone can soak up lots boil and natural gas,
Speaker 4: and the shale basically keeps it from leaving that arch. So,
Speaker 4: because oil is less dense than water, it rises to
Speaker 4: the top of the arch, but then it can't rise
Speaker 4: any higher. The overlying shale acts as like a ceiling
Speaker 4: and keeps it from escaping.
Speaker 2: This is like a geological Rube Goldberg machine.
Speaker 4: Yeah, man, it is. And so people have tried to
Speaker 4: shortcut this, you know in some places where they've you know,
Speaker 4: said like, hey, we've got these tarsands up in northern Alberta.
Speaker 4: They're full of petroleum, but it hasn't yet escaped the
Speaker 4: source rock. But we can make it escape by grinding
Speaker 4: up those things and then boiling them essentially, and then
Speaker 4: we can let the oil out and then we can
Speaker 4: burn the oil. But that takes a lot more energy investment,
Speaker 4: and so that really only becomes viable economically if oil
Speaker 4: prices are really high, like higher than one hundred and
Speaker 4: fifty dollars a parel.
Speaker 1: So I bet they'd really like to have oil on
Speaker 1: Mars though, And if you're already spending all that money
Speaker 1: to get to Mars, maybe you're willing to spend as
Speaker 1: much as it takes to get the oil out. Is
Speaker 1: it in difficult places or does Mars just not have
Speaker 1: the right conditions?
Speaker 4: I mean, I think Mars does not have the right
Speaker 4: condition So if we think about the various things that
Speaker 4: are necessary, like, did Mars have oceans in the past, Yeah,
Speaker 4: maybe probably? Did those have life in them? That seems
Speaker 4: like it's a little less likely. Did Mars have a
Speaker 4: sufficiently active surface environment to bury sediments? You know, enough
Speaker 4: subsidence in these areas where you'd get organic sediments buried.
Speaker 4: Mars certainly doesn't have plate tectonics, which is what crumples
Speaker 4: those sedimentary layers up into those folds that concentrate the oil.
Speaker 4: But maybe there would be some other equivalent trap on Mars.
Speaker 4: It does seem like though each of these things is
Speaker 4: far less likely on a planet like Mars than it
Speaker 4: is on a planet like Earth.
Speaker 2: How likely do you think it is? In general? We
Speaker 2: took a random planet and I said, there are oceans
Speaker 2: and there was microbial life. What are the chances that
Speaker 2: it has oil on it? Are we talking like one
Speaker 2: in two one in two million?
Speaker 4: Insufficient data, Daniel, insufficient data. So we do not know
Speaker 4: that the parameters of these different exoplanets. But like one
Speaker 4: of the things that's necessary here on Earth to bury
Speaker 4: the phytoplankton in their little graveyard at the bottom of
Speaker 4: the sea is you need to have something to bury
Speaker 4: them with, right, so you need to have sediments. Well
Speaker 4: where are those sediments coming from. They're coming from terrestrial
Speaker 4: and again I mean land source areas here where rocks
Speaker 4: are being weathered and they're shedding off particles big and small.
Speaker 4: But if you have a planet that's completely aqueous, where
Speaker 4: it's it's got no land, then what is going to
Speaker 4: bury those things in the first place? There's no source
Speaker 4: for sediments other than like chemical precipitates from the ocean itself.
Speaker 4: So there's no way I could put a number on
Speaker 4: how likely it would be. I appreciate the question, it's
Speaker 4: worth articulating, but I cannot answer that.
Speaker 1: We have focused on single cell organisms because we got
Speaker 1: this great question that focused on single celled organisms on Earth.
Speaker 1: Is all of our oil from algae or is it
Speaker 1: also from like dinosaurs and stuff, because that would be cooler.
Speaker 4: Okay, so it's not from dinosaurs and stuff. So dinosaurs
Speaker 4: and stuff are terrestrial organisms. They live on the land,
Speaker 4: they wander around on the land. When they die, they're
Speaker 4: very unlikely to be preserved in the fossil record. You know,
Speaker 4: we are very attracted to dinosaurs, we go to museums
Speaker 4: to see their fossil remains. But the reality is that
Speaker 4: they are far, far, far far less common than marine organisms,
Speaker 4: particularly marine invertebrates. So the fossil record is strongly biased
Speaker 4: towards things that live in the ocean, things that don't
Speaker 4: have backbones, things that lived a long time ago, like
Speaker 4: during the Paleozoic, Dinosaurs, you know, were limited to a
Speaker 4: relatively brief window of geologic time. And also the fossil
Speaker 4: record is biased towards things that have hard parts, such
Speaker 4: as bones or shells or teeth. Dinosaurs do have bones,
Speaker 4: of course, but you know, three of those four are
Speaker 4: kind of stocked against dinosaurs basically entering the fossil record
Speaker 4: in the first place. Usually when a dinosaur dies, it's
Speaker 4: flesh rots away because it's out here in the open
Speaker 4: atmosphere where there's lots of oxygen that wants to react
Speaker 4: with all the carbon in its body. And that's if
Speaker 4: it doesn't get eaten or scavenge. Right, So what we
Speaker 4: really want is circumstances where you know a dinosaur, maybe
Speaker 4: you know, dyed, bloated with gas, a flood washed it
Speaker 4: out to sea, then out at sea it popped, and
Speaker 4: then its skeleton and its remains could join the oil
Speaker 4: forming process. But that is really unlikely because that's not
Speaker 4: its natural habitat. No, it's not dinosaurs. But basically it's
Speaker 4: anything organic that could enter these low oxygen settings where
Speaker 4: sediments will then bury them and they'll get warmed up
Speaker 4: to the right temperature. Let me maybe at this point
Speaker 4: invoke an organism that you may have heard of or
Speaker 4: may not have, the conodont. Do you guys know what
Speaker 4: connodants are?
Speaker 1: No?
Speaker 4: Okay, So for a very long time, geologists are trying
Speaker 4: to figure out how old sedimentary layers are, and we
Speaker 4: figured out that the fossils in those sedimentary layers change
Speaker 4: through time. So for instance, you find dinosaurs in some layers,
Speaker 4: you find trilobites in other layers, you find woldy mammoths
Speaker 4: in other layers still, right, So there is a time
Speaker 4: progression to the geologic record where the fossils change in
Speaker 4: a regular and predictable way. This is awesome on many levels.
Speaker 4: It's a record of past biological evolution on our planet.
Speaker 4: But it also is kind of a tool for figuring
Speaker 4: out how old the sedimentary layers are, and when coupled
Speaker 4: with other tools such as isotopic dating, say, have a
Speaker 4: granite dike that cuts across a trilobyte bearing shale. You
Speaker 4: can then figure out, by dating the dike how old
Speaker 4: the shale must be. The shale must be older than
Speaker 4: this igneous rock that cuts across it. So we've been
Speaker 4: using this principle of relative dating by fossil succession for
Speaker 4: centuries now to figure out how old sedimentary rocks are.
Speaker 4: Leonardo da Vinci even practice this all right. So these
Speaker 4: fossils are most useful when they are distinct and recognizable,
Speaker 4: when they're very cosmopolitan and widespread all over the planet,
Speaker 4: not limited to some particular habitat or land mass or
Speaker 4: island or whatever, And when they are limited to a
Speaker 4: brief period of geologic time. So those three characteristics make
Speaker 4: for a good index fossil. Cockroaches are lousy index fossils
Speaker 4: because they've been around for hundreds of millions of years.
Speaker 4: So you find a rock with the cockroach in no
Speaker 4: big deal. It doesn't really tell you that much. But
Speaker 4: connidants are powerful index fossils. So they are these little
Speaker 4: things shaped kind of like teeth or spike balls, or
Speaker 4: they look like sort of sadistic ice skates or something
Speaker 4: like that. They are made out of a mineral complex
Speaker 4: called hydroxyl appetite, and they're found in sedimentary rocks the
Speaker 4: world over from the Cambrian period of geologic time up
Speaker 4: through the Triassic or Jurassic. Sometime in the Middle mesozo
Speaker 4: and people were like, hey, these things are awesome. You
Speaker 4: can really use them to tell these rocks apart. But
Speaker 4: they're different ages. We had no idea what they were, right,
Speaker 4: So they were just these things that we could find,
Speaker 4: these entities, and we were like, Okay, they're useful, but
Speaker 4: we don't know what they are. And recently they found
Speaker 4: out that they're part of the head region of an
Speaker 4: eel like critter, so a very small, little thin fish
Speaker 4: where the other parts of its skeleton are not hard
Speaker 4: enough to enter the fossil record, but they found one
Speaker 4: of these rare fossil occurrences where we've got the soft
Speaker 4: tissues preserved, the muscle blocks and some of the skin,
Speaker 4: the eyeballs. They've got great big eyes, so they look
Speaker 4: to be like sort of gill support structures or something
Speaker 4: related to the mouth, but not traditional teeth like you
Speaker 4: or I have. And these things are really neat because
Speaker 4: they can not only tell us time, but they change
Speaker 4: color when they get different temperatures. So a geologists at
Speaker 4: the United States Geological Survey, Anita Epstein, figured out that
Speaker 4: you could use the color of Kanada to figure out
Speaker 4: if the rocks had gotten to the right temperature to
Speaker 4: generate oil. So they would basically go from sort of
Speaker 4: a yellow color to an orange to a burnt umber
Speaker 4: kind of orange brown to a gray brown to black,
Speaker 4: and you could figure out exactly the temperature that they
Speaker 4: were cooked at, and that could tell you whether the
Speaker 4: rocks at that depth got to be the right temperature
Speaker 4: for oil production. A pretty neat trick. They call it
Speaker 4: the connidant alteration index. And there's a nice little article
Speaker 4: on Wikipedia you can read if you're interested in exploring that.
Speaker 1: More So, when people are like trying to figure out
Speaker 1: where oil is. If they find one of these things
Speaker 1: and it's the right color, are they like, Okay, now
Speaker 1: we need to dig in this area a lot more.
Speaker 1: And that's like an indicator that you're in the right spot.
Speaker 4: Yes, and if it's the wrong color, don't bother.
Speaker 1: Okay, and mars, we'll have none of this. So we're
Speaker 1: we're out of luck there. But that's awesome.
Speaker 2: My last question is do all these names they give
Speaker 2: to soils and rocks maneuver? Do these actually make sense?
Speaker 2: Or is it a big pile of nonsense the way
Speaker 2: it is in astronomy, with arbitrary dotted lines that date
Speaker 2: back to like some old man in robes in seventeen
Speaker 2: hundreds who gave something the wrong name.
Speaker 4: I mean, I'd love to tell you that it all
Speaker 4: makes perfect sense, but you know, like the English language,
Speaker 4: the geological lexicon has adopted words from other traditions, other languages.
Speaker 4: I really like thinking about the origins of these different words.
Speaker 4: I think kana dant. I'm sure that breaks down into
Speaker 4: something like cone shaped tooth in terms of its etymology.
Speaker 4: But geology is very rich with words from French, Italian, Scottish,
Speaker 4: even Indonesian Bahasa. Indonesia has contributed major words to the
Speaker 4: geological lexicon, and I love that sort of melting pot
Speaker 4: aspect of the science. It's very appropriate for the Indonesians
Speaker 4: to have a word for a volcanic mudflow, a lahar,
Speaker 4: but you wouldn't expect that to originate from Scotland. But
Speaker 4: it's very appropriate for the Scots to come up with
Speaker 4: words like esker and turn, which described glacial features. So
Speaker 4: it tells you something sort of almost anthropological about the
Speaker 4: place where these words originate.
Speaker 2: There's like sentiments of words that build up over time.
Speaker 4: That's a good way of thinking of it. And probably
Speaker 4: some of these words are almost like index fossils, right
Speaker 4: where they come into fashion for a while, they're used,
Speaker 4: and then you can only find them in the deepest,
Speaker 4: dustiest pages of the literature, which is.
Speaker 1: Where we love to explore. All right, well, thank you
Speaker 1: so much, Callen. This was super helpful, and we're going
Speaker 1: to send your answer to Ust and he'll tell you
Speaker 1: if he feels like his question was answered right on.
Speaker 4: Okay, good luck, everybody.
Speaker 2: I love talking to geologists. They rock.
Speaker 1: I bet Callen has never heard that.
Speaker 3: Sure, Hi, Kellen, Daniel and Kelly, thank you for those
Speaker 3: rock solid answers. I'll put my plans for a oil
Speaker 3: company on Mars on a hold.
Speaker 2: Now, thank you.
Speaker 1: All right, Well, I am so glad that youst felt
Speaker 1: like he got his question answered. And so now let's
Speaker 1: take a break and we'll move on to a question
Speaker 1: from Scott, who unfortunately is from California. We don't all
Speaker 1: get to pick where we're from.
Speaker 2: All right, we're back and we're answering questions from listeners
Speaker 2: like you. If you have a question about the universe
Speaker 2: that nobody you know can answer, send it to us.
Speaker 2: We will answer it for you. We write back to everybody.
Speaker 2: Send us an email to questions at Danielankelly dot org.
Speaker 1: Well try to get you an answer. Not all questions
Speaker 1: have answers, but we will do our best. But I
Speaker 1: guess there's no answer is also a kind of answer.
Speaker 2: Mm hmm. Yeah. The answer nobody knows is unfortunately the
Speaker 2: answer to most questions. And today we have a thorny
Speaker 2: question from Scott from California. He's asking about a famous
Speaker 2: physics experiment. It leads to all sorts of tricky philosophical wrinkles.
Speaker 5: This is Scott from California. I have a question about
Speaker 5: the double slit experiment. I am imagining a probability wave
Speaker 5: of a particle approaching the first barrier that has the
Speaker 5: slits in it. As the wave approaches that first barrier,
Speaker 5: I'm assuming that the universe has to make a decision
Speaker 5: about whether the particle is going to hit the barrier
Speaker 5: or go through a slit. That is, the wave function
Speaker 5: would collapse, and the particle would find itself hitting somewhere
Speaker 5: on the barrier, or perhaps find itself right where a
Speaker 5: slit is. If it finds itself right where a slit is,
Speaker 5: does the wave function then instantly uncollapse such that it
Speaker 5: goes through bow slits simultaneously. This question has been bothering
Speaker 5: me for a long time, so I'm really looking forward
Speaker 5: to getting an answer. Thank you so much, oh Man Scott.
Speaker 5: That is a great question.
Speaker 1: And I have vague memories of the double slit experiment
Speaker 1: from freshman year of college, but I guess that's twenty
Speaker 1: years ago now. Oh my gosh, So Daniel, well refresh
Speaker 1: my aging memory. What's the double slit experiment?
Speaker 2: Yeah, I think it's useful to nail down exactly what
Speaker 2: we're talking about. So we can figure out how best
Speaker 2: to answer Scott's question. This is a famous experiment that's
Speaker 2: been done in many ways, with changing interpretations over time.
Speaker 2: So the first version of this experiment was done with light.
Speaker 2: You have some source of light, a light bulb or
Speaker 2: a laser or whatever, and you shine it on some
Speaker 2: barrier and most of the light is absorbed, but you
Speaker 2: have two little slits in the barrier, and where those
Speaker 2: slits are the light can go through. So now on
Speaker 2: the other side of the barrier you have these two
Speaker 2: little narrow slits which act like sources of light themselves, right,
Speaker 2: almost like you have two little light bulbs right there.
Speaker 2: And then the light that comes from these slits hits
Speaker 2: some screen, and that's where you're observing it. You see
Speaker 2: on the screen, it's not just like light from the
Speaker 2: two slits. You see an interference pattern. You see that
Speaker 2: in some places it's dark even though the light hits it,
Speaker 2: and other places it's very bright. And that's explained by
Speaker 2: light being a wave and canceling out in some places
Speaker 2: and adding up in other places. So the first earliest
Speaker 2: version of this experiment showed us that light had these
Speaker 2: wave like properties because it interfered with itself on the screen.
Speaker 1: Okay, I'm following that, but I feel like I also
Speaker 1: have a vague memory of physicists talking about light as
Speaker 1: a particle. Yeah, what's going on there?
Speaker 2: So now it gets weird. Remember, the crucial explanation for
Speaker 2: why do we have interference is that we have light
Speaker 2: coming from both slits, right, Each one is like a
Speaker 2: little source, and sometimes their waves go up and the
Speaker 2: other one is going down, and sometimes they're both going up,
Speaker 2: so they add up. But the crucial thing is you
Speaker 2: have two sources, which is why you have interference. So
Speaker 2: then slow the experiment down. Now we know light is
Speaker 2: actually made out of little packets. It's not like a
Speaker 2: continuous stream. Right when you turn on your flashlight, it's
Speaker 2: actually shooting out little packets of light, these things we
Speaker 2: call photons. And so you can make this experiment more
Speaker 2: interesting by slowing it down and saying, what happens if
Speaker 2: we only have one photon in the experiment at a time, right,
Speaker 2: instead of huge numbers of photons which you're interfering with
Speaker 2: each other, what happens you have a single photon and
Speaker 2: then you see something very strange, which is the interference pattern.
Speaker 2: Builds up gradually on the screen. So one photon comes
Speaker 2: through and it lands in one spot, another photon goes
Speaker 2: through it lands in a different spot, and then the
Speaker 2: third one in another spot. But if you do a
Speaker 2: million of these, it adds up to give you the
Speaker 2: same pattern you saw when you illuminated it with a
Speaker 2: huge amount of photons all at the same time. So
Speaker 2: the confusing thing there is, and I can see Kelly's
Speaker 2: faces going hot, is what's doing the interfering Because in
Speaker 2: the earlier version I explained that the interference pattern is
Speaker 2: coming from having two sources. But if the one photon
Speaker 2: is in the experiment at a time, what is it
Speaker 2: interfering with? That's the big puzzle.
Speaker 1: Is the answer going to be quantum entanglement or something?
Speaker 1: Why do you all always make this so complicated?
Speaker 2: The answer is definitely quantum mechanical, though not entanglement. What's
Speaker 2: happening here is that the photon is not like a
Speaker 2: little particle that has a specific path and it goes
Speaker 2: through this slit and then hits the screen. The photon
Speaker 2: has a probability to go through one slit or the
Speaker 2: other slit, or to get absorbed by the barrier. Right,
Speaker 2: we don't know where an individual photon is going to go,
Speaker 2: and it's that uncertainty, that probability that's doing the interfering.
Speaker 2: So remember that picture I painted in your mind of
Speaker 2: light going through the experiment and coming out of the
Speaker 2: slits as little sources and then interfering with itself. You
Speaker 2: can use that exact same picture, except instead of thinking
Speaker 2: about it in terms of light, think about it in
Speaker 2: terms of probability for one photon. So you send that
Speaker 2: photon against the barrier, it has a probability to hit
Speaker 2: one slit or the other slit. That probability passes through
Speaker 2: both slits, right, And then that probability interferes with itself
Speaker 2: and creates a probability distribution on the screen in the back.
Speaker 2: Then the universe has to pick, Okay, where is this
Speaker 2: photon actually going to go? So I can put it
Speaker 2: somewhere on the screen, and it draws from that probability distribution,
Speaker 2: and it puts one photon, So that probability distribution guides
Speaker 2: each individual photon. It puts more where the probability is
Speaker 2: U is high, in other words, where the interference pattern
Speaker 2: is bright, and fewer where it's dark, So that it
Speaker 2: gradually it builds up the same interference pattern you saw
Speaker 2: when you shown the light brightly. So you just replace
Speaker 2: the concept of light waves with probability waves and all
Speaker 2: the same math works.
Speaker 1: Awesome. I think I had been imagining when we were
Speaker 1: sending a particle through the slits that we had directed
Speaker 1: it to one slit in particular, not that it could
Speaker 1: have gone through both. But it's not like I had
Speaker 1: the probability stuff in my head. So I still, yeah,
Speaker 1: anyway makes sense now, awesome.
Speaker 2: Yeah, it's crucial that you don't know in advance which
Speaker 2: slid it goes through, that you have the possibility for
Speaker 2: it to go through both slits, because then the other
Speaker 2: version of this experiment is, well, what if we check.
Speaker 2: What if we put a little detector like a camera
Speaker 2: or something that can tell whether the photon went through
Speaker 2: slit A or slit B. Then what happens, Well, then
Speaker 2: the universe picks witch slid it went through because you
Speaker 2: put a detector there, So you've collapsed the probability. Instead
Speaker 2: of allowing for the possibility that the photon goes through
Speaker 2: either slit, you now force the universe to pick which
Speaker 2: slid it goes through. So then the inner feference pattern disappears,
Speaker 2: and you just get photons going through one slit or
Speaker 2: the other slit, and you get a geometric shadow instead
Speaker 2: of an interference pattern because there isn't probability coming out
Speaker 2: both slits because you force the universe to pick and
Speaker 2: now it just sends a photon to one slit or
Speaker 2: the other slit. This is this bizarre process we don't
Speaker 2: fully understand of how possibility becomes reality when the quantum
Speaker 2: meets the classical.
Speaker 1: It still absolutely blows my mind that just measuring it
Speaker 1: changes the pattern that you get on the back wall,
Speaker 1: Like is it just shy? And like you know, what
Speaker 1: is the leading theory for why observing it changes things.
Speaker 2: It's not something we understand very well. And this is
Speaker 2: called the measurement problem in philosophy of physics. It's really
Speaker 2: a puzzle. I mean, we have this quantum theory that
Speaker 2: says things of the quantum level follow these equations of probability,
Speaker 2: and that's the Shirtinger equation, and they can have weird
Speaker 2: properties like not having a specific location but instead having
Speaker 2: a probability to have several locations, or having ability to
Speaker 2: be spin up or spin down. You can maintain a
Speaker 2: superposition of different possible outcomes, different possible properties for yourself.
Speaker 2: That's what quantum objects can do. But we know that
Speaker 2: classical objects can't. Like when you have a screen, the
Speaker 2: photo either hits here or there. It doesn't like half
Speaker 2: hit here and half hit there. Or when you flip
Speaker 2: a coin, it's either heads or tails. It's not like
Speaker 2: half heads and half tails. So we have these two
Speaker 2: different worlds, the quantum world where you can have superpositions,
Speaker 2: and the classical world where you can't, and we don't
Speaker 2: really understand the transition between them. It's confusing because everything
Speaker 2: in the classical world, like quarters and me and you,
Speaker 2: are made up of quantum things. So the leading theory
Speaker 2: is sort of nonsensical. The leading theory, called the Copenhagen interpretation,
Speaker 2: says that all right, you have quantum stuff, and it
Speaker 2: can have multiple possibilities, and it can do all sorts
Speaker 2: of crazy wavel like things like interfere with itself and
Speaker 2: its own probability. But then when you interact with a
Speaker 2: classical object like an eyeball or a detector or a screen,
Speaker 2: then the wave function collapses and the universe to pick says,
Speaker 2: instead of this whole spectrum of possibilities, you just pick one,
Speaker 2: and that allows us to have classical outcomes like hey,
Speaker 2: it's up or it's down, the photon is here, photon
Speaker 2: is there. This collapse theory doesn't really work because number one,
Speaker 2: it violates like basic quantum mechanical rules like quantum information
Speaker 2: is never lost. And also it's not really well defined.
Speaker 2: Like when I said a quantum object meets a classical object,
Speaker 2: I wasn't clear on, well, what is a classical object exactly,
Speaker 2: because as I said earlier, all classical objects are made
Speaker 2: to quantum objects, and that's the puzzle. Nobody can define
Speaker 2: the barrier between quantum and classical objects, so we don't
Speaker 2: really understand it. We don't have a great explanation. It's
Speaker 2: one of the biggest open questions in philosophy of physics.
Speaker 2: Still so much left to do, still so much leve
Speaker 2: to do, exactly. So let's get to Scott's question. And
Speaker 2: Scott is thinking about what happens when the photon is
Speaker 2: approaching that barrier, and I think that he's imagining that
Speaker 2: either the photon hits the barrier and is absorbed, or
Speaker 2: hits one of the slits and goes through and I
Speaker 2: think Scott is thinking that maybe the universe collapses it
Speaker 2: at that moment when it either hits the barrier or
Speaker 2: goes through a slit, because it sort of encountered some
Speaker 2: big classical object, and then he's confused about how later
Speaker 2: we can say it maybe went through both slits and
Speaker 2: is there some uncollapse, Like how do you get multiple
Speaker 2: possibilities through that barrier? I think is essentially Scott's question,
Speaker 2: And the answer is that hitting that first barrier doesn't
Speaker 2: collapse the wave function because you've still left multiple possibilities.
Speaker 2: It can go through slit one or go through slit two,
Speaker 2: so both those possibilities propergly forward. So the short answer
Speaker 2: is the first barrier doesn't collapse the wave function unless
Speaker 2: you have a detector there that's saying like, hey, did
Speaker 2: you go through slit one or slit two? Because you
Speaker 2: allow the possibility of multiple slits, you allow the quantum
Speaker 2: mechanical properties to maintain and for there to be a
Speaker 2: superposition of two possible outcomes, and so then both of
Speaker 2: those possibilities go through the slits, and then you get
Speaker 2: the interference from those two two possibilities.
Speaker 1: So if it collapses at the two slits. Instead, you
Speaker 1: get a totally different answer.
Speaker 2: Yeah, if you collapse it at the two slits, which
Speaker 2: you can do if you put a little detector there
Speaker 2: and you say, I want to know which one it
Speaker 2: went through, then you get a totally different answer exactly,
Speaker 2: you get a different pattern on the screen. And crucially,
Speaker 2: you can't uncollapse Like when you collapse the wave function,
Speaker 2: you go from here a whole bunch of possible outcomes
Speaker 2: to now there's just one, and you can't ever uncollapse it.
Speaker 2: You've lost information, which is why it's so confusing. And
Speaker 2: we've said on the podcast before, like you can't lose
Speaker 2: quantum information. It can't be deleted from the universe. But
Speaker 2: this collapse theory does violate that principle of quantum mechanics,
Speaker 2: and people out there might be like, hold on, aren't
Speaker 2: you contradicting yourself? Yeah. Absolutely, And this is one reason
Speaker 2: why we haven't really figured this problem out, like we
Speaker 2: have this best explanation we have violates other things we
Speaker 2: know about the universe, so it's like a work in progress.
Speaker 1: Yeah, this is one of the really fun things I
Speaker 1: think about podcasting with a physicists. I hadn't realized there
Speaker 1: were so many works in progress, but it's exciting that
Speaker 1: there's so much left to discover. So I feel like
Speaker 1: I understood that. But let's go ahead and test ourselves
Speaker 1: and ask Scott if did we actually answer the question
Speaker 1: that you were asking, and if so, was the answer
Speaker 1: clear that's right?
Speaker 2: Or did we just collapse his brain? Okay, So it's
Speaker 2: my pleasure to welcome to the podcast, Scott Goldman. Scott,
Speaker 2: thanks so much for running in with your really fun question.
Speaker 5: Yes, thank you.
Speaker 2: So tell me you heard me and Kelly talk about
Speaker 2: the double slit experiment and what happens to the wavefront
Speaker 2: as it hits the first barrier and interferes afterwards. Tell
Speaker 2: me does that make sense to you? What questions do
Speaker 2: you have or meaning?
Speaker 5: So it makes sense to me, I guess it all
Speaker 5: comes down to one question, and that is, every time
Speaker 5: a particle is shot at that double slit, the barrier
Speaker 5: with the double slit, and there's a probability wave that
Speaker 5: comes to that barrier, it goes through both slits, interferes
Speaker 5: with itself, and when it gets to that detector screen
Speaker 5: the universe at that point then I guess has to
Speaker 5: make a decision where it hits. My question is does
Speaker 5: every particle that is shot at that barrier with the
Speaker 5: double slits go through and then hit the detector screen
Speaker 5: or do some particles not hit the detector screen because
Speaker 5: they actually hit the barrier somewhere instead of going through
Speaker 5: the two slits.
Speaker 2: Yeah, great question. The answer is the second one. Not
Speaker 2: every particle makes it through butt, and there's always a butt.
Speaker 2: Every particle has a probability of making it through, so
Speaker 2: there's sort of a lot of different outcomes. One outcome
Speaker 2: is you make it through one of the slits and
Speaker 2: you end up somewhere on the screen as a dot.
Speaker 2: Another possible outcome is you don't make it through at all.
Speaker 2: So imagine that probability wave approaches the first barrier, or
Speaker 2: the one with the slits in it. Some of the
Speaker 2: probability wave makes it through and interferes with itself and
Speaker 2: gives it a probability to hit the back screen, but
Speaker 2: a lot of it, as you say, hits the barrier.
Speaker 2: So then when you force the universe to roll the
Speaker 2: dice and say what is the outcome for this particular particle,
Speaker 2: A lot of them are going to hit the barrier,
Speaker 2: and most of the descriptions of this experiment. They sort
Speaker 2: of ignore that part because that's not so interesting. We
Speaker 2: pay attention mostly to the ones that go through because
Speaker 2: those are the ones that do the interfering. But yeah,
Speaker 2: a lot of them. If you ask, like, hey, what
Speaker 2: happened to this particular particle, you'd ance it would be
Speaker 2: that a lot of them hit the barrier and don't
Speaker 2: make it through.
Speaker 5: Okay, So that's the part I guess where I'm having
Speaker 5: trouble understanding because I'm imagining this probability wave approaching the barrier,
Speaker 5: and then when it gets to the barrier with the slits,
Speaker 5: the universe has to decide like, oh am I going
Speaker 5: to hit the barrier, or no, I didn't hit the barrier.
Speaker 5: I happen to I'm gonna be right in this little
Speaker 5: space where there's a slit. But then it goes through
Speaker 5: both slits.
Speaker 2: Right, yeah, So the universe doesn't necessarily have to decide there, right.
Speaker 2: What it can do is have several possible outcomes. The
Speaker 2: wave approaches the barrier, and now there are three possible outcomes.
Speaker 2: You go through one slit, you go through the other slit,
Speaker 2: or you reflect or maybe get absorbed, depending on the
Speaker 2: nature of the barrier. So the probability is sort of
Speaker 2: fragment there. But they don't have to collapse, right, They
Speaker 2: only collapse when you insist, you know. But if you
Speaker 2: don't insist, you know, you're like, well, I'm just going
Speaker 2: to allow the universe to keep doing its thing. Keep
Speaker 2: that within a black box or keep my eyes closed
Speaker 2: for that part of it, equivalent. Then it can continue
Speaker 2: to propagate all three possibilities that it reflects back, or
Speaker 2: that it goes through one slit, or that it goes
Speaker 2: through the second slit. It can maintain all of those,
Speaker 2: and it's maintaining the uncertainty that allows it to make
Speaker 2: that interference pattern.
Speaker 5: So some of the probabilities go through the slit, and
Speaker 5: then when it gets the detector screen, at that point
Speaker 5: it decides whether it actually made it through or hit
Speaker 5: the barrier.
Speaker 2: Mm hmmm, yeah, exactly. It doesn't have to collapse when
Speaker 2: it hits the barrier.
Speaker 5: Oh gosh, sorry.
Speaker 2: Yeah, no, that's yeah, it's amazing. It's sort of crazy.
Speaker 2: But the way to think about it is that it's
Speaker 2: allowing some of that probability. You can also think of
Speaker 2: it another way. You can think, you know that the probability,
Speaker 2: most of it gets zeroed out and only those two
Speaker 2: little narrow slits of probability remain. But there's still uncertainty there.
Speaker 2: You don't know which way, and so that's what allows
Speaker 2: for the interference. And I think a lot of people
Speaker 2: are confused by that. They're like, well, why doesn't the
Speaker 2: barrier collapse the wave function?
Speaker 6: Right right?
Speaker 2: And you can think about it that way also, and
Speaker 2: you can, for example, add detectors to the barrier so
Speaker 2: that the only possibilities for the particle are that it
Speaker 2: goes through a slit or it hits the detector, and
Speaker 2: that doesn't collapse the wave function completely. That just says,
Speaker 2: if it hits the barrier, then I want to know.
Speaker 2: If it doesn't hit the barrier, there's still uncertainty because
Speaker 2: they could still go through either slit and then you'll
Speaker 2: still get the interference pattern. So that scenario you could
Speaker 2: sort of partially collapse the wave function. You'd be like,
Speaker 2: if it hits the barrier, I want to know. Otherwise
Speaker 2: I'm going to allow for the uncertainty to propagate through
Speaker 2: both slits. So this is an infinite number of confusing
Speaker 2: and amazing ways to do this experiment. All right, well,
Speaker 2: I hope that helped you understand. Thanks so much for
Speaker 2: asking the question.
Speaker 6: Thank you, and we're back.
Speaker 1: Our final question of the day is a question from
Speaker 1: Lewis on Discord, and here is his question.
Speaker 7: Hi, Daniel Kelly, I was wondering what kind of adaptations
Speaker 7: might we make to humankind, whether genetic or bionic or anything,
Speaker 7: to help us to live on a place like Mars. Thanks,
Speaker 7: looking forward to hearing your answer.
Speaker 1: All right, Oh my gosh, there's so many problems on Mars?
Speaker 1: Which ones should we try to solve?
Speaker 2: I'm excited that you're optimistic about this. I thought your
Speaker 2: answer might be like, it's impossible to give up.
Speaker 1: I mean, the back of my mind is saying that,
Speaker 1: but I'm gonna let's try to have some fun. Let's
Speaker 1: start with the problems that could kill us. And so
Speaker 1: those problems are probably radiation, partial gravity, and depressurization. So
Speaker 1: I think those are the top three. What do you think, Daniel?
Speaker 1: Are those the top three worst problems on Mars?
Speaker 2: Those sound pretty bad, yeah, and I think I'd love
Speaker 2: to hear solutions to those. And this is great because
Speaker 2: it gives you an opportunity to demonstrate your optimistic side
Speaker 2: instead of just throwing cold water on humanity's prospects.
Speaker 1: Oh man, I hope that doesn't mean this is going
Speaker 1: to be a bad answer, because it's not in my
Speaker 1: skill set to be optimistic.
Speaker 2: Okay, let's see, all right, let's hold.
Speaker 1: Off on the depressurization problem till the end because the
Speaker 1: initial set of solutions that I have are not really
Speaker 1: good for depressurization. So one problem is radiation. So, as
Speaker 1: we've discussed on a couple other episodes, space has different
Speaker 1: kinds of radiation then we typically encounter on Earth. So
Speaker 1: you have solar flares and solar part of events, and
Speaker 1: these are like shooting protons.
Speaker 6: Boo boo, boo boo.
Speaker 1: You can dive right away from something like radiation sickness
Speaker 1: just shuts a bunch of your organs down all at once,
Speaker 1: or you can get cancer which will kill you slowly. Also,
Speaker 1: we have galactic cosmic radiation, not one hundred percent sure
Speaker 1: where it comes from. Could be from exploding stars in
Speaker 1: black holes, but we don't really know, right.
Speaker 2: Daniel, Yeah, exactly, Yeah.
Speaker 1: All right, So the galactic cosmic radiation tends to be bigger,
Speaker 1: like charged ion particles. I saw this one paper it
Speaker 1: was an old paper from like the seventies, but they
Speaker 1: got a gel that was meant to be sort of
Speaker 1: like the human body, and they shot an iron ion
Speaker 1: through it and it blew a hole the size of
Speaker 1: a human hair, which like, does I mean usually like, oh,
Speaker 1: size of a human hair that's used to indicate something small,
Speaker 1: but like, I don't want holes the size of a
Speaker 1: human hair in my brain. Like that's no good, no.
Speaker 2: And that's a great image because it reinforces the message
Speaker 2: that these things are not like little fuzzy quantum objects
Speaker 2: that somehow interfere with you. They are basically space bullets. Right,
Speaker 2: Space is shooting at you, and we have a bulletproof
Speaker 2: vest here on Earth. Right our atmosphere is protecting us.
Speaker 2: It's absorbing all that kinetic energy and we're lucky. And
Speaker 2: so yeah, how do we deal with life on Mars
Speaker 2: without our atmospheric bulletproof vest Kelly?
Speaker 1: The easiest solution is probably something related to shielding. But radiation, well,
Speaker 1: space makes everything complicated. But one way radiation is complicated
Speaker 1: is because of something called spellation. So when galactic cosmic
Speaker 1: radiation hits your habitat, it hits particles that it then
Speaker 1: breaks into other kinds of particles that are also radioactive
Speaker 1: and now rain down on you and what's called a
Speaker 1: nuclear shower. See, Daniel, you asked me for a solution,
Speaker 1: and I'm giving you reasons why it's worse. My pessimism
Speaker 1: is winning, all right, I'm backing up.
Speaker 2: Okay, So you're saying, if I walk around Mars with
Speaker 2: like an umbrella of some very heavy duty material to
Speaker 2: protect myself from radiation, it's actually just going to generate
Speaker 2: like showers of radiation underneath.
Speaker 1: The umbrella, depending on what the umbrella is made out of. Yes,
Speaker 1: so there are some particles that are better at absorbing things.
Speaker 1: I don't think anything's really great at absorbing galactic cosmic
Speaker 1: radia without breaking up. But could bury your habitat in regolith,
Speaker 1: which we've talked about before. But you know, human bodies
Speaker 1: can repair some damage, and some of us are better
Speaker 1: repairing damage than others. And so let's assume that part
Speaker 1: of the solution is you're burying your habitat and regolith.
Speaker 1: But you could also specifically send two Mars people from
Speaker 1: Earth who are more radiation resistant, and to be honest,
Speaker 1: I don't know how we pick those people yet. Because like,
Speaker 1: we don't have a lot of experience with space radiation,
Speaker 1: but presumably there's variation in this trait. So you could
Speaker 1: send more radiation resistant people up to space, and at
Speaker 1: least for the first generation, that might help maybe.
Speaker 2: Because they are like less likely to get cancer. They
Speaker 2: have some sort of like genetic predisposition, Like biologically, how
Speaker 2: does that work? What is it about some people that
Speaker 2: makes them like more rad proof than others?
Speaker 1: No, great question? Who knows, right, Here's Kelly, We don't really,
Speaker 1: you know, And so that there are some people who
Speaker 1: are like, well, you know, we can pick people who
Speaker 1: are more radiation resistant, and then we could figure out
Speaker 1: what it is about them that makes them more radiation resistant,
Speaker 1: and then we could try to use genetic engineering to
Speaker 1: tinker to make the next generation more radiation resistant, and like,
Speaker 1: through this combination of crew selection and genetic engineering, we
Speaker 1: can create people who can survive better in space. Here's
Speaker 1: a tiny little bit of pessimism. Really quick, I won't
Speaker 1: linger too long. But you know, most of the important
Speaker 1: human traits are not controlled by like a gene that
Speaker 1: you can tinker with. So like our genetic engineering of
Speaker 1: humans that has gone best so far has involved tinkering
Speaker 1: with genes that don't get past to babies and dealing
Speaker 1: with diseases that are caused by like a mutation in
Speaker 1: one spot. So if radiation is controlled by one hundred genes,
Speaker 1: you could tinker with all those genes. But the other
Speaker 1: problem is that genes usually don't just do one thing,
Speaker 1: so when you tinker with all those one hundred genes,
Speaker 1: you might be messing up other stuff too. So actually,
Speaker 1: let's go ahead and say that's not the best solution.
Speaker 1: And now, because I have a physicist on the show
Speaker 1: and an optimist, maybe I'm going to kick to you.
Speaker 1: So let's imagine that we are living in an environment
Speaker 1: where we have where money is no problem, and we
Speaker 1: have as many nuclear portable nuclear power plants as we
Speaker 1: could possibly need. Could you use electricity in some way
Speaker 1: to protect your habitat from space radiation? I know it's
Speaker 1: energetically expensive, but like, could we super coil?
Speaker 5: Like?
Speaker 1: Are what are our solutions here?
Speaker 2: Yeah? Well, these things are mostly ions, right, and so
Speaker 2: these they are charge particles, and those charge particles can
Speaker 2: be repelled or redirected by electric fields, but they're very,
Speaker 2: very high energy. The good thing is that the very
Speaker 2: high energy ones are rarer, so while it'd be much
Speaker 2: more challenging to redirect the high energy ones, there are
Speaker 2: less common. The rate falls very very quickly with energy.
Speaker 2: But yeah, it would cost a huge amount of energy.
Speaker 2: I mean, really, the better way to do it is
Speaker 2: a magnet, right, rather than relying on their electric field,
Speaker 2: because that's what the Earth does. The Earth has a
Speaker 2: magnetic field, and we deflect a lot of this stuff.
Speaker 2: There actually is a fun proposal to put a huge
Speaker 2: magnet between the Sun and Mars to create like a
Speaker 2: magnetic shadow for Mars to deflect these particles. And I
Speaker 2: asked a friend of mine who's a planetary scientist who
Speaker 2: has actually worked on like Mars missions, and he says, quote,
Speaker 2: this is literally the dumbest idea I have ever heard.
Speaker 2: I almost fell out of my chair when I saw
Speaker 2: someone presenting it.
Speaker 1: Okay, I feel like pestimist, I know.
Speaker 2: And I asked him to elaborate, and he says, quote,
Speaker 2: there are so many reasons it's stupid. You have to
Speaker 2: somehow make a giant magnet. You'd have to put it
Speaker 2: on a ginormous spaceship and keep it in orbit around
Speaker 2: the lagarage point, and It goes on to point out
Speaker 2: that not all of the radiation comes directly from the Sun,
Speaker 2: so the shadow wouldn't even protect you. And a lot
Speaker 2: of the radiation are UV photons, which do not have
Speaker 2: a charge and will not be deflected by magnets or
Speaker 2: electric fields. You really need the combination of a magnetic
Speaker 2: field for your whole planet, not just a shadow, and
Speaker 2: you need an atmosphere to absorb the stuff that isn't charged.
Speaker 2: So yeah, physics doesn't have an answer for this one either.
Speaker 1: Oh man, okay, well, let's move on to the next problem.
Speaker 1: I don't have an answer really, And then of course
Speaker 1: there's all the ethical things that we just completely glanced
Speaker 1: over with genetic engineering, so that that is something else
Speaker 1: holding this all back, all right, So then the second
Speaker 1: problem is partial gravity. So Mars has forty percent of
Speaker 1: the gravity we find on Earth. We know that astronauts
Speaker 1: who experience no gravity when they're in free fall lose
Speaker 1: muscle mass, bone density, and that might explain why they
Speaker 1: start losing some of their vision or some of them,
Speaker 1: not all of them. Because the fluids, you know, we're
Speaker 1: adapted to have gravity pulling our fluids back down. So
Speaker 1: when we don't have that benefit. Fluids tend to go
Speaker 1: up and they like push on our brain and they
Speaker 1: might be changing the shape of our eyes. So forty
Speaker 1: percent gravity would that solve the problem. We don't know.
Speaker 1: Like some of those problems maybe bones and muscles, for example,
Speaker 1: that could possibly be solved by like putting on really
Speaker 1: heavy weighted outfits that sort of make it so that
Speaker 1: you're carrying around as much weight as you'd be carrying
Speaker 1: around on Earth. That might help keep everything nice and strong.
Speaker 1: I don't know if that's going to help with like
Speaker 1: fluid related problems or like anything else in your body
Speaker 1: that's associated with partial gravity, but you could, and I've
Speaker 1: seen proposals for this, create banked race tracks to create
Speaker 1: artificial gravity, and you could, I don't know, maybe sleep
Speaker 1: in those and that might be enough. And then I
Speaker 1: also have seen proposals for what are called sucky pants
Speaker 1: or sucky sleeping bags, and they they create a different
Speaker 1: kind of pressure and it pulls the fluids down, and
Speaker 1: so you could like sleep in these or wear these.
Speaker 1: They're like you have to tune them well because sometimes
Speaker 1: when they turn them on like too fast or too strong,
Speaker 1: the fluids rush out of your brain and people like
Speaker 1: pass out, which is not great and they don't look
Speaker 1: super comfy. But so there are some technological solutions.
Speaker 2: But to be clear, here you saying that we know
Speaker 2: there are problems in zero gravity, and now we're asking
Speaker 2: like is forty percent gravity enough? Like do we still
Speaker 2: have those problems in forty percent? And then what can
Speaker 2: we do about solving that additional bit? Right?
Speaker 1: Yeah? Right, So I am assuming that forty percent is
Speaker 1: not going to solve all of our problems. If it does,
Speaker 1: then great, we don't need any extra help. If we
Speaker 1: do need extra help, here are some things we could do.
Speaker 2: But who wants to live on like a banked racetrack
Speaker 2: their whole life? That doesn't sound like a fun place
Speaker 2: to hang out. Or maybe only part of the time
Speaker 2: you need to be on the racetrack.
Speaker 1: Yeah, we don't know. Maybe you could sleep on the
Speaker 1: racetrack and that would be enough, but I we don't know.
Speaker 2: Well, what about something like more inherent? Is there something
Speaker 2: we can do inside the body, you know, like to
Speaker 2: modify the structure of our bones or chain some fundamental
Speaker 2: process inside of us that'll just make us more naturally
Speaker 2: suited to that kind of environment. I'm thinking like really
Speaker 2: science fiction craziness here.
Speaker 1: I had fiction craziness. Okay, so right, So one of
Speaker 1: the questions would be, like, does our current genetic make
Speaker 1: up include enough variability where we could tinker with things
Speaker 1: in the right way to make us survive better in
Speaker 1: these environments? And so you know, maybe there are, for starters,
Speaker 1: people who have bones that are thicker than thicker than
Speaker 1: others and would maybe do better in an environment like this.
Speaker 1: And if we can figure out why they have thicker bones,
Speaker 1: maybe we could tinker with the DNA of future generations,
Speaker 1: which is a phrase that makes me shudder just thinking
Speaker 1: about it. But anyway, we could do that maybe and
Speaker 1: like thicken up their bones so that maybe it wouldn't
Speaker 1: matter if they're in an environment where you would expect
Speaker 1: bones to atrophy because they were already stronger to begin with.
Speaker 1: Like maybe that'll be enough. I really don't know. For
Speaker 1: this one. I kind of come up at a loss
Speaker 1: with radiation. I felt like it was maybe a little
Speaker 1: easier to imagine.
Speaker 2: Well, my question is like who's working on this stuff?
Speaker 2: Like can you do any kind of ethical research here
Speaker 2: in terms of like bioengineering humans or are people doing
Speaker 2: like bioengineering on rats and dogs and stuff, or just
Speaker 2: sort of theoretical. Is it possible to do research in
Speaker 2: this area.
Speaker 1: So with new Crisper technology, it's easier for us to
Speaker 1: tinker with genetic information, so to like cut bits out
Speaker 1: and replace it with other bits that we want, And
Speaker 1: we have used that to help out with some diseases,
Speaker 1: so for example, sickle cell anemia. By tinkering with some
Speaker 1: genes using Crisper CAST nine, we've been able to like
Speaker 1: make people's lives way better. So we are getting better
Speaker 1: at using some of these techniques in humans, which is
Speaker 1: a big step, I think, And so we're getting a
Speaker 1: little outside of my expertise. I think. The first time
Speaker 1: that technique was used on babies in a way that
Speaker 1: it would be transmitted across generations was done in China,
Speaker 1: and they got thrown in jail for that because the
Speaker 1: whole international community was like no, no, no, no, no.
Speaker 1: We were not okay. None of us are okay with this.
Speaker 1: You jumped way too far ahead. And so I think
Speaker 1: that research is gonna not move forward, I hope for
Speaker 1: a while.
Speaker 2: And if I could press on that for a moment,
Speaker 2: like I've always wondered, is there a crisp understanding of
Speaker 2: why it's okay to breed humans by selecting your mate
Speaker 2: but not by editing their genome is the only answer
Speaker 2: just like, well, this is a dull enough strategy that
Speaker 2: you can't like feel too bad if you mess up
Speaker 2: and you know your kid doesn't have the genetics you
Speaker 2: want it, or something like is it just the power
Speaker 2: of this technology to create horrendous outcomes?
Speaker 1: I think it's a couple things. So one thing is
Speaker 1: that we as a species have a lot of experience
Speaker 1: with mating and having babies and seeing how that turns out.
Speaker 1: But when you start tinkering with things at the genetic level,
Speaker 1: things don't always go the way you think they're going to.
Speaker 1: You know, you think you understand a system, you tinker
Speaker 1: with it, and maybe that child will have catastrophic issues
Speaker 1: they'll have to deal with for their whole life because
Speaker 1: you decided to tinker with their DNA, but just.
Speaker 2: To play devil's advocate. The same thing can happen when
Speaker 2: you choose your mate, Like, for example, if you're in
Speaker 2: a small community and you choose to select your partner
Speaker 2: inside your community, you open them up to possible conditions
Speaker 2: that come from genetic populations, you know, like I'm an
Speaker 2: Ashkenazi Jew. I know that tasax syndrome would have been
Speaker 2: a real risk if my partner was also an Ashkenazi Jew.
Speaker 1: Yeah, And so I don't think Zach would mind me
Speaker 1: admitting that he's a carrier and that I had to
Speaker 1: get that test because that was a real risk for us.
Speaker 1: But I think that is why we try to have
Speaker 1: genetic testing, so that you can be aware of these
Speaker 1: potential issues and make decisions based on that to avoid
Speaker 1: these worst case scenarios. And so I think we would
Speaker 1: say we don't want to stop people from marrying and
Speaker 1: having children with the people that they love, but we
Speaker 1: do whatever we can to minimize the negative impacts of that.
Speaker 1: I think trying to improve a bad situation you find
Speaker 1: yourself in is very different than trying to tinker to
Speaker 1: get something better that you would ideally have. And so,
Speaker 1: and I think that leads to the second problem with
Speaker 1: genetic engineering is that there's this concern that people who
Speaker 1: can afford to tinker with their kids are going to
Speaker 1: end up having like what often gets called in the
Speaker 1: press as like designer babies, and that we're going to
Speaker 1: further see inequality sort of exacerbated by this kind of thing.
Speaker 2: Right, Like I want my kid to be a long
Speaker 2: jump champion, so I'm going to give them this genetic package,
Speaker 2: which costs a million dollars or whatever. Yeah, that does
Speaker 2: seem like terrifying. I'm already terrified to make any sort
Speaker 2: of decisions from my kids, like oh, we're going to
Speaker 2: this high school or that high school, or you have
Speaker 2: to eat this way or that way, and I wonder
Speaker 2: that by the consequences for the rest of their lives.
Speaker 2: So yeah, I'm glad to not have to have made
Speaker 2: some genetic decisions.
Speaker 1: Yeah, well, and we should have, like you know, maybe
Speaker 1: maybe one day we'll have a bioethicist on the show
Speaker 1: to talk about this stuff, because it's complicated and I
Speaker 1: feel like the more you think about it, the more
Speaker 1: you're like, oh, but it would be great if we
Speaker 1: could do that. But it would be catastrophic if we
Speaker 1: could do that. And like, you know, there are people
Speaker 1: who spend their whole lives thinking about this much and
Speaker 1: much more detail than I did.
Speaker 2: Yeah, and the technology will be available eventually and then
Speaker 2: we're going to figure out what to do about that.
Speaker 2: But yes, let's have an expert on who actually knows
Speaker 2: this stuff.
Speaker 1: So, staying on genetic engineering for a second, there are
Speaker 1: folks who argue that we need to start doing this
Speaker 1: kind of engineering now because it's really important that we
Speaker 1: start having self sustaining settlements on Mars as soon as
Speaker 1: we can, because we never know when something catastrophic could
Speaker 1: happen to the Earth, and it seems like a lot
Speaker 1: of catastrophic things are happening lately. So it's important that
Speaker 1: as soon as we can we get people living on
Speaker 1: Mars in a way that can happen sustainably. And so
Speaker 1: maybe that should make all of our ethical concerns, those
Speaker 1: concerns should be dwarfed compared to the importance of keeping
Speaker 1: the human species going. I don't personally buy that argument,
Speaker 1: but you know, there are these emerging debates about the
Speaker 1: ethics of doing it, and how those ethics sort of
Speaker 1: change if we think that this is something we need
Speaker 1: to be doing quickly for the safety of our species.
Speaker 2: Wow, it's so hard to imagine what the future of
Speaker 2: humanity holds. It can go in so many different directions.
Speaker 1: And because I'm a pessimist, I will go ahead and
Speaker 1: note the one final way you can get humans that
Speaker 1: are well adapted to the Martian surface, which is natural selection,
Speaker 1: which every once in a while you'll see noted in
Speaker 1: the literature as like, oh, well, you know, after enough
Speaker 1: generations have people who are well adapted to the Martian surface,
Speaker 1: And of course that means many, many people will die
Speaker 1: and root, and it's not even one hundred percent certain
Speaker 1: that we have the right kind of genetic variability where
Speaker 1: eventually there will be people who can survive you know,
Speaker 1: radiation on Mars are living in forty percent gravity, and
Speaker 1: so we might just lose a bunch of people, which
Speaker 1: sounds really awful.
Speaker 2: Also, don't you assume that you start from a pretty
Speaker 2: large population, Like if you start from ten people, it's
Speaker 2: unlikely you're randomly going to have the right genetic mutation.
Speaker 2: You need to start from a pretty big population, right,
Speaker 2: which means a lot of people are going to die,
Speaker 2: like big numbers.
Speaker 1: Wow. Agreed, Yes, you know, But you know Musk would
Speaker 1: argue with Starship he can get a million people there
Speaker 1: in thirty years, and he can, you know, keep sending people.
Speaker 1: I should clarify, Musk is not the one who has
Speaker 1: said we're going to let natural selection solve the problem.
Speaker 1: He hasn't been clear on how this problem's going to
Speaker 1: get solved. Free market somehow, free market something something. The
Speaker 1: next thing we're going to talk about wouldn't solve the
Speaker 1: partial gravity problem, but would solve problems related to radiation
Speaker 1: to some extent, and depressurization. So the problem with depressurization
Speaker 1: is that when human bodies go from an area of
Speaker 1: higher pressure to an area of lower pressure, the nitrogen
Speaker 1: bubbles out of our blood, and if it gets stuck
Speaker 1: in your joints, it causes the bends because it hurts
Speaker 1: so much that you bend over in pain. If those
Speaker 1: bubbles get stuck in your lungs, you get the chokes,
Speaker 1: it's hard to breathe. If they get stuck in your
Speaker 1: nervous system, you get the staggers, You get these nervous
Speaker 1: system problems. But if it happens to you in space,
Speaker 1: you're just going to get the death, which unfortunately is
Speaker 1: what happened to the crew of Solute one they got
Speaker 1: exposed to the vacuum of space in the seventies. So,
Speaker 1: how do we make a Martian atmosphere thick enough, with
Speaker 1: enough pressure so that you could go outside without a
Speaker 1: spacesuit and you wouldn't have to worry about your habitat depressurizing,
Speaker 1: and Daniel, I think the only solution to that would
Speaker 1: be terraforming. Could you thicken up the atmosphere and the
Speaker 1: pressure enough by the proposals that I saw involved like
Speaker 1: sending nuclear weapons to the poles so that you could
Speaker 1: blow up the ice there, and that that ice would
Speaker 1: then distribute itself in the atmosphere and would thicken up
Speaker 1: the atmosphere, and that might even warm up the planets.
Speaker 1: Could that solve the atmosphere thickness problem and radiation or
Speaker 1: we just noking a planet for no reason.
Speaker 2: It's not an easy answer. Like Mars is like one
Speaker 2: percent of the Earth's atmosphere, so you'd need to increase
Speaker 2: the atmospheric pressure by a lot. And there definitely is
Speaker 2: CO two and the poles of Mars, and you could
Speaker 2: release some of it. But the problem is that if
Speaker 2: you release too much CO two then the atmosphere becomes
Speaker 2: poisonous to humans, and so it doesn't really solve the problem,
Speaker 2: and you'd need a lot of CO two. You need
Speaker 2: to like scoop up some of it from Venus and
Speaker 2: transfer it over to Mars, So this is not an
Speaker 2: easy way to manufacture the kind of atmosphere you want. Ideally,
Speaker 2: you want a huge amount of oxygen in the atmosphere
Speaker 2: so you can walk around without a suit, But oxygen
Speaker 2: is hard to make. You know, you basically need some
Speaker 2: sort of like micro trubes growing on Mars eating this
Speaker 2: theo too and producing oxygen. And my wife is a microbiologist,
Speaker 2: and she thinks that would take millions of years optimistically,
Speaker 2: And you know on Earth it took quite a long time.
Speaker 2: And the rocks are going to drink a lot of
Speaker 2: that oxygen before it even stays in the atmosphere. And
Speaker 2: we know that Mars is like likes to get rusty,
Speaker 2: and we don't know if you can gobble up more
Speaker 2: of that oxygen. So terraforming is not an easy solution,
Speaker 2: which is why I think this question is actually asking
Speaker 2: for another kind of solution, like what can we do
Speaker 2: to change ourselves so we can walk around in that
Speaker 2: one percent, Like could we engineer some sort of crazy
Speaker 2: high pressure skin that's basically like a suit, or change
Speaker 2: something fundamental about a biochemistry so we could just happily
Speaker 2: walk around in one percent atmosphere.
Speaker 1: Daniel nothing's coming to me. Do you have an answer?
Speaker 1: I mean, even if you had high pressure skin or like,
Speaker 1: what would high pressure skin be like, like you turn
Speaker 1: your skin to metal.
Speaker 2: Basically, I just have a natural suit, you know, as
Speaker 2: part of your body. It's not really an answer. Basically
Speaker 2: you're wearing a suit, but it's part of who you
Speaker 2: are now, So technically it might be a solution.
Speaker 1: But like, if you open your eyes or your mouth,
Speaker 1: aren't you exposing yeah, yourself to the pressure change? Like,
Speaker 1: I don't see this working.
Speaker 2: Look, I only solve the problem for a minute. I
Speaker 2: don't know's to lunch?
Speaker 1: You know, Well you got you know, incremental you gotta
Speaker 1: let the market something something exactly.
Speaker 2: The first candidate survived until lunchtime and then they depressureize.
Speaker 2: So let you know, we take a break and come
Speaker 2: back and tell the rest of the problem another time. Yeah,
Speaker 2: I think the answer is that it's hard, right. Pressure
Speaker 2: is important, and we are just really not designed to
Speaker 2: survive in a low pressure environment. You're right. We exchange
Speaker 2: all sorts of fluids and materials with the environment, and
Speaker 2: so sething ourselves off from it is not really a solution,
Speaker 2: and it's hard to imagine well, what if we somehow,
Speaker 2: like inflated humans, we lived in a low pressure environment.
Speaker 2: I'm imagining like a completely different kind of biological being,
Speaker 2: you know, where, like your insides are actually at lower pressure.
Speaker 1: I can't imagine you'd be able to do that with
Speaker 1: current genetic variability that's like available, But I mean you could.
Speaker 1: I guess, like every generation you lower the pressure in
Speaker 1: the habitat, and whoever survives you work with that. But
Speaker 1: that would take a long time and would not be ethical.
Speaker 2: No, not even close to ethical. No, absolutely not. All right,
Speaker 2: so it sounds like we're not going to be adapted
Speaker 2: to living on the surface of Mars very soon, and
Speaker 2: even our craziest technological solutions are not really well suited
Speaker 2: to the task.
Speaker 1: I have to admit, I don't feel like we came
Speaker 1: up with any super satisfying answers. But let's go ahead
Speaker 1: and ask Lewis if he feels like we did the
Speaker 1: best we could.
Speaker 2: I'm terrified what kind of grade we're going to get.
Speaker 8: Thanks so much, Daniel and Kelly. I did not appreciate
Speaker 8: quite the cannon Williams. I was looking man, and I
Speaker 8: definitely get the message. I think I'm going to stick
Speaker 8: around on Earth for a little while longer.
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