What would life on Earth be like if our planet were cube-shaped?

It’s coming home. In the season one finale of Dead Planets Society, our hosts Leah Crane and Chelsea Whyte are taking on everyone’s favourite planet: Earth. But fear not – they’re not destroying it entirely, just reshaping it a bit. Gravity naturally encourages objects in space to form spheres, but in this episode, Earth is getting cubified.

Transforming Earth into a cube is difficult, so our hosts have turned to geophysicist and disaster researcher Mika McKinnon for help. No matter how you do it, Earth’s going to be uninhabitable for a while. But once things settle down, life on our home planet would be drastically different.

For one thing, if Earth were molded into a cube but kept the same mass and the same amount of water, the oceans would pool up into six seas, one on each face of Cube Earth protruding from the surface like a huge lens. The atmosphere would behave similarly, not reaching the edges or corners. This would leave a narrow inhabitable zone around each of the six seas with bleak mountains beyond the atmosphere.

Space exploration would, in some ways, be simplified – all you’d have to do to get into the vacuum of space would be to build a shielded rover and trundle off towards the edges of the world. Those edges would be perfect for space launches and telescopes, with no air to hamper things, but the constant earthquakes as gravity tries to make the planet a sphere again might make things tough.

Then, in the second part of the finale episode, coming out on 22 November, our hosts and McKinnon take on what life will be like on Cube Earth. Days will seem different, as each sunrise and sunset would happen suddenly across each face of the planet. The world’s new shape and the six bubbles of atmosphere would encourage something like island evolution, potentially producing strange wildlife and enormous sea monsters.

Dead Planets Society is a podcast that takes outlandish ideas about how to tinker with the cosmos – from putting out the sun to causing a gravitational wave apocalypse – and subjects them to the laws of physics to see how they fare.

To listen, subscribe to New Scientist Weekly or visit our podcast page here. Dead Planets Society will be back with season two in 2024.

Transcript, part one

Mika McKinnon: So, think about if you want to go outside the magnetic field you have to be in your little fish bowl.

Leah Crane: Yeah, I want to cruise around in my all-terrain fish bowl.

Chelsea Whyte: Why are we outside Earth’s magnetic field? Because we’re making the planet a cube. Welcome to Dead Planets Society, everybody.

Leah Crane: This is a podcast where we imagine what it might be like if we were given cosmic powers to rearrange the universe.

Chelsea Whyte: I’m Chelsea Whyte, US editor at New Scientist.

Leah Crane: And I’m Leah Crane, physics and space reporter at New Scientist.

Chelsea Whyte: And welcome to the first episode of our two-part season one finale. This one is a doozy, folks.

Leah Crane: This week it’s time for the most dangerous game. We’re taking down Earth.

Chelsea Whyte: And in true Dead Planets Society fashion we’re doing it in glorious style.

Leah Crane: Glorious, geometric style. We’re making it a cube.

Chelsea Whyte: Cube Earth, Cube Earth, Cube Earth.

Leah Crane: Cube Earth, Cube Earth.

Chelsea Whyte: I truly love this idea and I can’t wait to find out how we could slice the planet’s faces off.

Leah Crane: Thanks, Hannibal.

Chelsea Whyte: You’re welcome. But also I’m curious what will it do to gravity, or time, what would it be like to live on Cube Earth?

Leah Crane: Well, I’ve done a little bit of research so one thing I do know is that it would be absolutely wild. Or should I say, it will be absolutely wild? We’ve also got geophysicist and disaster researcher Mika McKinnon to help us out, and we started by asking her what’s the best way to make Earth a cube?

Mika McKinnon: I think that’s actually the most challenging part, is trying to get the cube, and then once you have the cube just, kind of, assuming that it stays that way, because when left to its own devices, anything big enough is going to go in the spherical and/or lumpy potato direction. Just that’s how gravity works. So first you have to get it into a cube, then you have to keep it into a cube. So I thought that we would start and keep the same mass, because if you start screwing with the mass of the Earth then really you don’t have the Earth at all anymore. So I figured you need to, like, shave down the sides and stick them up in the corners, kind of like a big ball of clay going on. And if you really think about the Earth, it’s not exactly solid, you just have, like, a solid shell, so if you had enough force it is a giant lump of really warm clay, really warm green and blue clay at that. So I’m just going to be like, ‘Look, let’s just have, like, giant cosmic hands doing this. Like, I don’t know, maybe we’re using specially shaped primordial black holes? Why not? Giant chisels?’

Chelsea Whyte: Or it sounds like, like my first instinct was we need a cosmic chisel to slice off the faces of this cube but it sounds like it might be better to have, like, a mold, like a Playdough mold.

Mika McKinnon: Yes, and just smash it in.

Leah Crane: You know how they grow those, like, fancy watermelons?

Chelsea Whyte: Oh, yeah, the cube watermelon.

Mika McKinnon: Yeah.

Leah Crane: Could you just put a mold that’s gently squishing and wait? Because there is a lot of liquid.

Mika McKinnon: Yes, we can take the toddler approach and be like, round peg, square hole, we’re set. Just squish that nice, round planet into a square mold and push it down enough, then good enough.

Leah Crane: Oh great.

Mika McKinnon: So we’re going to take the same mass that we had before and if something kind of goes squishing out, that’s okay. It helps that the mantle of the Earth – so the Earth has the solid inner core, liquid outer core, then the big, gooey mantle and the tiny, thin little crust. And the tiny, thin, little crust is we’re just going to, like, shatter it like an egg shell on a freaking hard boiled egg, whatever, it doesn’t matter. We squish it then it will reform, it’s no big deal, we do that all the time.  The mantle-y bit, you’re probably thinking of it being like an ocean of lava because that’s how we draw it in text books but it’s not, it’s blue, and green, and gooey. So it’s more like oatmeal.

Chelsea Whyte: Literally blue and green?

Mika McKinnon: Yes, yes, yes, the inside of the Earth is blue and green. I mean, it’s really, really hot so it’s probably glowing red, but the rocks themselves are blue and green, if you had colour when completely surrounded by a solid which is like this whole philosophical problem of, like, what is the colour of the inside of a human, right? Like, are the insides of humans actually red or is it only red because you rip them open and take a peek? In this case we’re going to rip the planet open and take a peek so deep blue and green aside from the fact it’s glowing red hot. So, like, the whole concept of colour just kind of falls apart a bit. But, so blue and green squishy inside of the planet and we’ll just kind of squish it out and, like, the core will probably not get re-shaped during this.

Leah Crane: Once we cube it, it sounds like we’re going to probably have to wait a while for the crust to reform because every method we’ve thought of makes Earth, like, super unpleasant to be on for a bit. Like, you don’t want to be on the surface while we’re putting it in the mold.

Mika McKinnon: It’s okay because the earth is going to be super unpleasant no matter what for a while. So if we’re starting off and we’re going to try and keep things to be the same mass, then we end up with, like, a little cubical Earth with everything the same size in every direction, which it is not right now, like, you think Earth is a sphere, hey, we have a consistent radius. No, we don’t, we’re like a squished sphere that is actually really lumpy so it’s more like a potato. So we’re already going in to the realm of, like, hey, this is a more perfect planet than we have. But even if we squish everything, the gravity is still going to be pointing to the centre, so everything inside is still going to be all circular, so we’re still going to have, like, the magnetic field of the Earth, hot metal moving fast, it’s that our core is going to still generate a doughnut-shaped magnetic field. So you’re still going to get your northern and southern lights only above those parts of the cube. Oh, by the way, do we want to have the Earth rotating through a flat part? A face? Or do we want it rotating through a corner?

Chelsea Whyte: So, this was a good question that we were talking about. Like, yes, I think it’s interesting in both ways but I prefer, for some reason, aesthetically to be spinning through a corner. Like a little-

Leah Crane: I’m the exact opposite.

Chelsea Whyte: Yeah?

Leah Crane: I think that it’s a funner if it’s spinning like a cube because then you’ve got a whole edge that’s on the edge moving instead of just one little corner. You’ve got-

Chelsea Whyte: Also days would be really weird, right? Like all of a sudden the sun would hit an entire face if it was spinning with a-

Mika McKinnon: Oh yeah. Light and time are just going to be all over the place, but also magnetic fields are going to be all over the place because they’re still going to be doughnut-shaped, and that’s going to impact things like you still have your cosmic rays moving fast every time they hit the field, they light up, it’s like effectively northern and southern lights are this, like, ‘Hey, how you doing on hardening your electrical grid? It’s really beautiful and pretty up here, we’re ready to zap you all.’

So anything poking out of the magnetic field is not protected from the zappage, which is- we’ve talked about this in terms of concerns for when the Apollo missions happened we were like, ‘Hey, you know, just so everyone’s aware, if there’s, like, a coronal mass ejection towards the moon during the Apollo missions we’re just going to have a bunch of fried astronauts up there.’ And they had, like, the emergency speech set aside and everything. So that’s everything outside the magnetic field is just, kind of, death land.

Leah Crane: Screwed.

Mika McKinnon: Yes, well, I mean, it’s, you know, you can come up with ways to protect yourself from cosmic rays, like, you can wander around in giant tanks of water, would be one way of doing it. Or lead encasements.

Chelsea Whyte: I wish you could have seen our faces. That was incredible. I want to be in a giant tank of water.

Leah Crane: Fish tank, fish tank, fish tank!

Mika McKinnon: Yes, exactly.

Chelsea Whyte: One of my deep wishes is to live in the ocean, in the deep sea, and I could just take it with me.

Mika McKinnon: Exactly, and we talk about this in terms of, like, how would we do deep space exploration of humans, well, one of the things we have to talk about is how do we keep people protected when we’re going outside our magnetic field to somewhere else. And one of the concepts is, well, maybe you could just put all the water that you need anyway, put it on the outside of the spaceship, and store it on the outside to be a beautiful shield to absorb all the ways the universe is just trying to casually kill you as you explore deep space. So, we can do that. So, think about if you want to go outside the magnetic field you have to be in your little fish bowl or, like, giant lead aprons and X-ray machine style like, ‘Hey, let’s just put on the dentist robes and go for a stroll.’ But that’s not the only problem.

Chelsea Whyte: I prefer the fish bowl.

Leah Crane: Yeah, I want to cruise around in my all-terrain fish bowl.

Chelsea Whyte: So, let’s talk about what this would look like from afar. So that means we’d have this cubed planet but each face would have like a, like a half sphere, like a little contact lens of water on it. Is that right?

Mika McKinnon: Yes.

Chelsea Whyte: And then where would the atmosphere- would the atmosphere be also in that weird dome on each face?

Mika McKinnon: Yeah, so-

Chelsea Whyte: We’re living in the dome, we’re living in the dome in our fish bowls.

Leah Crane: We would have, like, six domes but they would not be connected.

Mika McKinnon: Yeah, there’d be six little domes on six little faces and each one would be surrounding a little sea, and if you look at the size of the ocean and you look at the size of the atmosphere and how much water and how much gas we’re working with here on Earth, we’re talking about all of humanity living in a little ten kilometre fringe around each of these lakes.

Chelsea Whyte: Incredible.

Mika McKinnon: So, space is defined by how much atmosphere you have, right? Like at some point you go high enough up that you’re like, ‘There’s not enough air, I’m in space.’ It’s not very high, it’s like 200 kilometres, right? And the edges of the cube are going to be, like, 1000 kilometres outside the atmosphere. So the edges of the cube will be in space by how we currently define things.

Leah Crane: We going to have to redefine space.

Mika McKinnon: Or we redefine spaceships so they have wheels, so you have a fish tank on wheels as your new spaceship because you can leave the atmosphere of your face, go up to the edge of the world, then go across the edge of the world to go explore the next isolated little bubble, right?

Chelsea Whyte: Imagine the tourism. Imagine it. I want to go on a trek to The Edge. Capital T, capital E, in my little fish bowl rover.

Leah Crane: I can picture it perfectly.

Chelsea Whyte: But gravity wouldn’t be that strong out there, would it?

Mika McKinnon: Well, you’d be dealing with mountaineering problems. So, going to space would also be mountaineering. It’d effectively be like Everest on extreme ends because gravity’s going to keep pointing towards the centre, but the centre when you’ve got a square is at an angle. So, when you’re at the- like, if you’re in the centre of the ocean, gravity’s pointing straight down. But by the time you get to the edges of the lake or of the sea, it’s going to be at a bit of an angle and you’re going to be, kind of, constantly walking uphill or downhill. Even though the surface is flat, your gravity is not. Your gravity is at an angle and the further you get from the centre, the bigger that angle gets.

You’ve only got, like- it’s a ten kilometre fringe so you can cross the entire width of your available coastline, breathable area, in, like, a two hour stroll. I mean, walking around the lake would take longer but you’ve got a very short distance before you’re going to need your fish bowl to keep going. Your, like, little oxygen bubble inside of a fish bowl on wheels to go to space. And the further you go towards the edge, the steeper your angle is going to be. We’re going to know that the edges exist because the horizon, if you’re in the middle of the ocean, the first thing you’re going to see is going to be the corners of the cube. And you’re going to be able to see them from, like, I think the fish bowl, or the little ocean lenses are, I think about 300 kilometres across. And if you’re in them, as long as you’re within 150 kilometres of the edge, or of the coastline, so as long as you’re not in the dead centre, if you’re, like, halfway to shore, you will be able to see a corner. But it’s not until you’re within, like, ten kilometres of shore, maybe fifteen kilometres of shore, that you’ll be able to see the flat areas actually nearby. So you won’t be able to see the human-inhabited portion unless you’re almost at the coast. You’ll only be able to see these corners jagging off, that are way out there, and have no air and no inhabitation, they’re just rock. So you see, like, these mountains off to the sides.

Chelsea Whyte: Would this look like a very large mountain or would it take up more of the sky?

Mika McKinnon: So, I’ve been trying to decide on that one and I think to some extent we’re going to have to play around with some optical effects here because right, like, you could tell things were flat, one of the first places you can tell that we have a round planet is in the ocean where you’ve got these beautiful horizons going on, and you can tell what’s going on with, like, sunsets and sunrises, why we have blue skies and red skies, from how much atmosphere you’re looking through. But that all gets muddled up when you’re dealing with, like, this tiny little bubble happening. And I think that you would end up still getting your red sunsets, but they’d be really close.

Leah Crane: It seems like it would be easier to do rocket launches from cube Earth, right? Because you have all those nice corners with no atmosphere.

Mika McKinnon: Instead of having all of our space ports at the equator like we do now where we can use the earth’s rotation to, like, fling things in to space, we’d instead probably have a two-stage spacecraft where stage one would be wheels and go to the corner of the earth, and stage two would be launch from the corner into orbit. And if you’re really lucky you can also do it with the rotations happening – depending where you have the axis of the Earth, you could shape it to be able to get that little gravitational assist anyway.

Leah Crane: I wonder if we got someone with mad hops, if they could jump off the corner of the earth in to space.

Mika McKinnon: If we could do, like trampolining?

Chelsea Whyte: Yeah, I want to pogo-stick into space.

Leah Crane: Oh my god.

Mika McKinnon: And we’re still dealing with the- it’s not that much lower, unfortunately.

Chelsea Whyte: Okay.

Leah Crane: Dang.

Chelsea Whyte: But these edges would also be, like, incredible places to do a whole lot of science. Like, I’m just thinking, put all the telescopes out there, right? Outside of the atmosphere.

Mika McKinnon: Oh, yeah, you have no atmosphere going on, you could actually walk out and repair them instead of having to deal with, like, the poor Hubble space telescope just slowly disintegrating as its stabilisers- you don’t have to worry about stabilisers. You have less gravity so you don’t have to deal with the mirrors warping as much. You have really predictable light cycles happening.

Leah Crane: Super- with a sharp edge.

Mika McKinnon: Yes, and you could do things like pick a corner and have a telescope on each side of the corner to have full coverage. And they could even share, like, a little processing centre just like we do in Antarctica right now. So yeah, you could do some really cool science with that.

Leah Crane: That seems pretty rad. I will say that it seems to me, and this might not be true, Mika, we’ll need your input, but it seems like if we’re cubing Earth and then we’re going to put some telescopes and stuff on there, it does seem like earthquakes might be a problem because of how much we’ve screwed up the planet.

Mika McKinnon: Yeah, I would say there’d definitely be a lot of, like, surface level earthquakes going on during the time where everything was cooling. All the bits that we destroyed would be cooling down and crunching, and as they cooled and crunched they would contract and you’d get some earthquakes from that but they’d be, you know, relatively surface-level earthquakes. But the whole planet would be trying to relax from a cube back into a sphere so it would always be trying to have, like, the corners crumble in and the flat bits bulge out unless we’re keeping it in our mold. So you’d definitely have some fairly large earthquakes from that as it’s all just trying to sag out. So I’d recommend we come up with, like, an Earth sized pair of Spanx to shove it in. Keep it, like, forcefielded into place. Because after you go through all the effort of building a cubical planet you, kind of, want to keep it.

Chelsea Whyte: Yeah.

Leah Crane: I like the idea of shapewear but the shape is a cube.

Mika McKinnon: Look, everyone has their own aesthetic preferences, we do no shaming here.

Chelsea Whyte: Okay, we’re going to have to end it there, but we’re not done at all. We had so much more conversation with Mika that we’re coming back tomorrow with Cube Earth, Part II, the last episode of season one.

Leah Crane: We’ll get into how Cube Earth is just mega-Australia, the absolutely wild climate that’ll happen there, and the inevitable sea monsters that cubing the earth would create.

Chelsea Whyte: Thanks again to Mika McKinnon for joining us, and to all of you for listening. If you have any questions or ideas for destroying the universe, get in touch at [email protected].

Leah Crane: Or if you just want to chat about what Cube Earth would be like, you can find us on X – I’m @downhereonearth and Chelsea is @chelswhyte. Bye!

Topics:

Source link

#life #Earth #planet #cubeshaped

Is it possible to drill a hole straight through a planet?

It is the mission of children on beaches around the world: to dig through the centre of the planet and come out the other side. But such an endeavour is far from simple. Earth isn’t just sand and rocks all the way through – it holds a sea of molten iron, and the temperature and pressure near the middle would be enough to melt any ambitious digger, along with any tools they might use to make their hole.

In the second episode of the Dead Planets Society podcast, our intrepid hosts Leah Crane and Chelsea Whyte dig into the question of what might happen if we were to bore a hole through a planet. Gas giants are probably a no-go, because the temperatures and pressures below their clouds are too intense for any material humans have ever made to stay intact, let alone for actual humans to survive.

For an indestructible vessel, though, the journey would be interesting, with strange gravitational effects and phases of matter we have never seen before. Maybe on a smaller world, like Pluto, you wouldn’t need an indestructible vessel – in fact, Pluto’s surface is so cold that a person’s body heat would be enough to start a borehole. Planetary scientists Konstantin Batygin and Baptiste Journaux join our hosts this week to talk about the logistics of drilling through an entire world, and what would happen if we could actually pull that off.

Dead Planets Society is a podcast that takes outlandish ideas about how to tinker with the cosmos – from unifying the asteroid belt to destroying the sun – and subjects them to the laws of physics to see how they fare.

To listen, subscribe to New Scientist Weekly or visit our podcast page here.

Transcript

Chelsea Whyte: Now I want to skateboard with intention through Mars and do a sick flip on the way out.

Konstantin Batygin: There you go. There you go. Yes.

Chelsea Whyte: The X Games goes galactic.

Leah Crane: Welcome to the Galactic X Games, also known as Dead Planets Society.

Chelsea Whyte: This is a podcast where we imagine what would happen if we were given cosmic powers to rearrange the universe. I’m Chelsea Whyte, senior news editor at New Scientist.

Leah Crane: And I’m Leah Crane, physics and space reporter at New Scientist.

Chelsea Whyte: And today, we’re talking about destroying a planet. But only mostly destroying it. And we’re not discriminating, any planet will do.

Leah Crane: And we don’t necessarily want to wreck it entirely. We just want to bore a hole straight through the middle.

Chelsea Whyte: Yes. So big, small, doesn’t matter. Rocky, gas giant, who cares? Let’s go get one of these suckers.

Leah Crane: Yeah. We’ve got to figure out which planets it would be possible to drill through.

Chelsea Whyte: And that’s probably not going to be Earth, right? For a lot of reasons.

Leah Crane: Yeah, almost definitely not Earth. But we’ll get into that in a little bit when we talk about what it would be like to drill this big ol’ tunnel and how we could get it to stay open. But the planets are all different and this is really complicated, so we got some expert help.

Chelsea Whyte: Right. So we spoke with Baptiste Journaux from the University of Washington, and we’ll bring him in a little bit later.

Leah Crane: Yes but right now, we’ve got some information from Konstantin Batygin from Caltech who talked a bit about what the best planet to drill through might be.

Konstantin Batygin: You’d have the best chance of actually drilling a hole through Mars. Because, like, if you think about the Earth, right, eventually you’ll reach the liquid iron core and then you’re going to have to worry about the fact that it’s liquid, so it’s hard to drill a hole through liquid.

Leah Crane: Okay. So we want to pick the smallest one without a magnetic field.

Konstantin Batygin: Yes.

Leah Crane: Because no magnetic field means no moving liquid metal in the middle.

Konstantin Batygin: That’s right. So Mercury’s magnetic field is much more complicated, so we’ll see. But I think Mars is a good bet for this.

Chelsea Whyte: I mean, I’m on board, I’ve always wanted to shoot, Mars but it seems like we might have a hell of a time trying to get through the rock.

Leah Crane: Yes, that’s why Baptiste said we might want to aim for something a little bit smaller.

Baptiste Journaux: Digging a hole through a planet is incredibly hard, or near impossible if you think really, you know, about the physics of it. So literally the smaller the better, you know, as you might expect.

Chelsea Whyte: Is the smaller the better simply because there’s less distance to go? Or less gravity? Or all of it?

Baptiste Journaux: Actually, none of the above.

Chelsea Whyte: Oh.

Baptiste Journaux: The main problem is temperature. Because as soon as you start to go below the surface of a planet, there’s going to be remnant heat from the formation of that planet. Very quickly, you’re going to rise to temperatures that are way above the melting temperature of metals so you would just literally melt, like, the boring bits that you use. So that’s the main issue.

Chelsea Whyte: Okay. So our machinery would melt.

Baptiste Journaux: Yes. I mean, before it would melt it would probably act like play dough, in a way. You would start to dig in but eventually you would get, like, so hot that even metals would start to become soft and they will just like, yes, become like very, almost gooey.

Chelsea Whyte: Okay.

Leah Crane: Okay, so if we’re using anything metal to drill this hole it’s going to become gumby and then melt.

Baptiste Journaux: Yes. I mean, just to get things, like, if you actually look at real things that happened, we actually tried to dig a hole, the deepest possible hole in Siberia.

Leah Crane: The Kola Superdeep Borehole?

Baptiste Journaux: Yes, that’s right. The Kola Superdeep Borehole. And they went all the way down to roughly twelve kilometres. So twelve kilometres, that might seem a lot but it’s so small compared to the entire thickness of the Earth – that’s closer to 6,300 kilometres. So we didn’t even pass the crust. We were still inside the crust, we didn’t even punch through the first very thin layer of the Earth, we didn’t even enter the mantle, because the crust is roughly 30 kilometres in that area. And they had to stop mostly because of temperature because, like, the drill bits would just get destroyed.

Leah Crane: I wonder, I mean, I guess you have the same problem, but as much as smaller is better seems like the obvious choice, it also seems like gas is easier to get through than rocks. Would a gas planet be easier for a little bit, and then much worse, or…

Baptiste Journaux: Pretty much, I mean, the problem with gas is that it doesn’t stay in place so if you dig a hole then the gas that are next to it are just going to replace the gas that you just removed. But if you are to imagine that you would be able to apply a force field that just keeps the gas from going in-

Leah Crane: Yeah, or we just leave a tunnel behind us.

Baptiste Journaux: Here you go. We have this magic power and we can just keep whatever we remove from the hole from being replaced by the gas that is next to it, very quickly you’re going to run into the exact same type of problems, which is mostly temperature. Because on planets like Jupiter, Saturn, Uranus and Neptune, even though the surface is really cold and, you know, you have the cloud deck and then you get to a higher pressure, the main problem is that the temperature is rising very quickly so very fast you’re going to past the melting point of lead or aluminium, all the other metals-

Chelsea Whyte: Humans. Yes. (Laughter).

Baptiste Journaux: And humans. And humans. That’s actually one of the things I tell in my class is that, what happens if you just drop someone in Jupiter? First they would probably suffocate because, you know, you can’t really breathe the atmosphere. But after this, while you fall, yeah, you’re going to literally get cooked and eventually you will dissolve in what we call metallic hydrogen. So it’s, like, hydrogen that is so compressed that it becomes metallic and it’s so hot that it can dissolve pretty much everything. And so you would just, like, dissolve things in the planet before you’d even reach even halfway through the planet you will get totally dissolved before that.

Chelsea Whyte: You become the gas planet.

Baptiste Journaux: Yes. So gas and ice planets they are, kind of, it’s not a realistic description for what most of the volume is. Okay, there is gas at the exterior, but very quickly you become fluid because you pass this point, the thermodynamic point that we call the critical point where you cannot make the distinction between gas and liquids because you’re too high pressures and too high temperatures. And most of, Jupiter and Saturn for example, are mostly in this, like, super high pressure, super high temperature fluid state so they’re more like fluid planets rather than gas planets. So the temperature we’re talking about, I mean, very quickly you get into the thousands of kelvin but at the centre you can get to, yeah, tens of thousands of kelvin. I think it’s around, like, 30,000 kelvin or something like that.

Leah Crane: So even if we were able to dig through and leave a, sort of, slide behind us, of openness, the tunnel would be a really unpleasant place to hang out.

Baptiste Journaux: Oh, absolutely. Absolutely. It would be a terrible place. Actually if you have a tunnel, very quickly you will reach a place with this type of temperature and they would actually glow because, you know, anything that is hot emits a blackbody radiation. But because it’s hotter than the surface of the sun it would shine brighter than the surface of the sun so you would have, like, a hole that is emitting a bunch of light probably.

Leah Crane: Ooh.

Chelsea Whyte: Okay, but would the light come out either end?

Baptiste Journaux: Possibly, yes.

Leah Crane: It’s sounding more fun now.

Baptiste Journaux: You would have, like, a very, very expensive torchlight.

Leah Crane: So it would be blindingly bright.

Baptiste Journaux: Yes, very impractical.

Leah Crane: Thousands of degrees.

Baptiste Journaux: Yeah. I mean, at 30,000 kelvin which is the temperature of the centre, yeah, most of the light coming from it would probably be in the ultraviolet but you will still have a lot of light coming from the visible spectrum so it will be very, very bright. So you have this extra bright spot coming from the tunnel, probably.

Chelsea Whyte: So you’d be blind and cooked. But let’s say I jumped in-

Baptiste Journaux: Yes, and dissolved.

Chelsea Whyte: And dissolved.

Leah Crane: You’d be soup.

Chelsea Whyte: If I wasn’t soup and I jumped in, would I also get stuck in that bad, awful middle place? Like, would the gravity, sort of, pull me in? Even if I got going pretty fast and overshot it wouldn’t it, kind of, yank me back and I would end up stuck?

Baptiste Journaux: So let’s take the idea of, like, we have a hole through a planet and you’re not cooked, you’re not burned or whatever, but you drop from the same altitude as the surface and just fall through the entire planet. So every planet is different and the evolution of the gravitational pull with distance to the centre can either increase or decrease when you get closer. So for example, on Earth, the gravitational attraction is pretty much the same until you reach, like, the core of the Earth. And then it starts to decrease. For planets like Jupiter or Saturn, the gravity actually increases as you go down because you get closer to the high density areas of the planet. So if you have, like, super high density areas it will actually attract you more. So if you were to just fall through that thing, what’s going to happen is you’re going to happen is you’re going to accelerate and the more you fall, you know, the more acceleration you get and so you arrive at the centre with an incredible speed.

Chelsea Whyte: So Konstantin had thoughts about this too. I asked him if I would go through all the way through and, sort of, pop out the other side and land on the surface or if I would get caught in the middle by gravity and fling back and forth forever.

Konstantin Batygin: At the centre, there’s zero gravitational acceleration because there’s no mass interior to you. But what would happen is you would fall in, you’d accelerate, you’d reach maximum speed as you go through the centre, and you’d come out the other side. I mean, it’s just like half pipe, right? Like, if you’re going down a half pipe on a skateboard, you’re going fastest at the bottom where it’s flat. Right? And then you come up to the other side of the half pipe and you’re not going very fast at all which is why you can do whatever you guys like to do on the half pipe.

Leah Crane: And if I’m not jumping through with intention then I’m just going to end up, sort of, wobbling back and forth, just like I would if I didn’t drop into the half pipe with intention.

Konstantin Batygin: Right.

Chelsea Whyte: Okay but now I want to skateboard with intention through Mars and do a sick flip on the way out.

Konstantin Batygin: There you go. There you go. Yes.

Chelsea Whyte: The X Games goes galactic.

Leah Crane: I love it. This would be the worst slide ever.

Chelsea Whyte: Yeah. It would be very unpleasant.

Baptiste Journaux: I mean, that would be really fun for the first five minutes. Maybe.

Leah Crane: That’s longer than I expected.

Baptiste Journaux: Yes. After that it becomes very unpleasant but it’s going to be very unpleasant for a very short amount of time, so.

Leah Crane: Right. And then you’re dead.

Baptiste Journaux: It’s not going to be a very long torture. You’ll be cooked very quickly. I mean, the temperature in Earth for example, in the crust, increases by 30 Celsius per kilometre so, you know, after two or three kilometres you will already be above the boiling part of water so you’ll literally boil out and cook out after the first three kilometres, so. And that’s really close to the surface.

Chelsea Whyte: I think even just the first kilometre sounds like enough for me. That’s a lot of heat.

Leah Crane: Okay, so let’s say we’re not jumping in because of, we don’t want to die.

Chelsea Whyte: Fair enough.

Leah Crane: Then we don’t have to keep the tunnel open so it seems like a gas giant might be an easier target, because I can imagine myself burrowing through gas more easily than the liquid iron core of a planet.

Konstantin Batygin: I mean, you’d be burrowing through metallic hydrogen so it would be not too different after all. Right? Like, the moment you go down, I think it was 0.82 Jupiter radii or 0.92 but if you started going inside Jupiter, pretty quickly you reach a situation where hydrogen becomes a metal. And the interior pressure, of course in Jupiter, is larger than inside the Earth at, sort of, at the tens of megabars level.

Chelsea Whyte: Just to interject here, a megabar is a unit of pressure that’s about a million times the atmospheric pressure at sea level on Earth.

Leah Crane: Every once in a while you get a reminder that a gas giant is maybe a bit of a misnomer.

Konstantin Batygin: Yes, I mean, it’s made out of hydrogen but hydrogen goes metallic under high pressure.

Chelsea Whyte: But what if you didn’t go straight through the centre? What if you, like, did a glancing blow? Sort of through the upper parts of Jupiter? I’m having a hard time picturing punching a hole through gas, in general, but would it be possible to keep something open?

Konstantin Batygin: I mean, it’s like being in an aeroplane. Right? And also Galileo had a probe that, sort of, did this. Galileo, not the person, but Galileo the spacecraft dropped in a probe into Jupiter and, you know, that’s how we know some of the abundances in the atmosphere. So yes, it’s a lot like being in an aeroplane.

Leah Crane: Yeah, I feel like the glancing blow is really, like, if we were to do a glancing blow through the centre of Earth, that’s just, like, a water line. Those exist, we’ve got tunnels. You’ve been on a train? That’s a glancing blow through Earth.

Chelsea Whyte: Yeah, yeah.

Konstantin Batygin: I think from now on we should rename all tunnels to glancing blows through the Earth.

Chelsea Whyte: Yes, correct.

Konstantin Batygin: It’s like, imagine you’re driving, right? And whatever your Siri or your Google Maps is like, ‘And now, execute a glancing blow to the Earth for point one miles.’

Leah Crane: Yeah. It’s like, “I’ll be there in fifteen minutes, I’m just travelling through the centre of the Earth.”

Chelsea Whyte: I like it.

Leah Crane: ‘Like, the centre?’ ‘No, just a little bit below the surface.’

Konstantin Batygin: Yes. I like it. I like it, this is good.

Leah Crane: So, my other thought if we’re not maintaining this bore hole is that I could just burrow through something icy like Pluto, like, inside of a heated drill bit or something.

Baptiste Journaux: Probably. Yeah, on Pluto-

Chelsea Whyte: But could a person live inside something hot enough to burrow through Pluto but not too hot to cook you?

Baptiste Journaux: So the main advantage of Pluto is that it is so cold, the surface is around 30 kelvin, you know, even a human at the surface, by just the body heat that we produce, would actually sink through.

Chelsea Whyte: You, yourself are the drill bit.

Baptiste Journaux: Yes.

Leah Crane: Yeah.

Baptiste Journaux: Yes, you, yourself are the drill bit. Until you actually emit enough heat that your body temperature starts to cool down and then you just, like, freeze in place. I mean, that would be a very terrible way to die actually, like, drop someone on the surface of Pluto and-

Leah Crane: Just watch them melt.

Baptiste Journaux: See them, like, slowly sink. Yes, like, slowly sink through the surface and eventually disappear and being re-covered by nitrogen ice for example.

Leah Crane: Be just buried alive inside Pluto.

Baptiste Journaux: Yes because on Pluto we have different types of ice because it’s so cold that, you know, we’ve all heard that liquid nitrogen is really cold and we probably have seen liquid nitrogen, solid nitrogen is even colder and so if you were to put just a human- even in a spacesuit, the temperature of it will be enough to sublimate the nitrogen so you would just, like, literally sublimate yourself through until a certain depth and then, yes, you will get cool enough and you would probably get stuck there.

Chelsea Whyte: But Pluto is an interesting test case because we were talking about how other planets would get too hot, do we think Pluto would get very hot at its centre as well?

Baptiste Journaux: I mean, the temperature eventually will get too hot, that’s guaranteed. But it’s like, at what depth? That’s the main question I have. So yes, probably the first 300 kilometres would be okay, you know, at 300 kilometres we could be close to room temperature.

Chelsea Whyte: Oh.

Leah Crane: We can build a little house 300 kilometres under the surface of Pluto.

Baptiste Journaux: I mean, you would still be at a super high pressure so it would be better for, like, deep sea fishes. They would be very comfortable there.

Chelsea Whyte: Oh, okay.

Leah Crane: Okay.

Baptiste Journaux: It would be temperate for them.

Chelsea Whyte: So we just need a whale on this. Yes.

Baptiste Journaux: Yes, like, a sperm whale would be very happy there probably.

Chelsea Whyte: Okay, heat up the sperm whale, send him to Pluto.

Baptiste Journaux: Yes, exactly. It’s super cheap. Small rockets.

Chelsea Whyte: Yes, just a tiny project.

Baptiste Journaux: Yes. Yes, like, the sperm whale space programme.

Leah Crane: You could just build a really big catapult. Big trebuchet. Chuck a whale to Pluto.

Chelsea Whyte: In, like, a little water capsule that’s warm. See how far we can get it into the planet.

Baptiste Journaux: I mean, there’s not that many left so many we should leave the sperm whales alone.

Chelsea Whyte: Yes, I mean, we should be nice to them. But I think that would be, like, the most historic sperm whale. They would go down in sperm whale history.

Leah Crane: Yes, they could repopulate.

Baptiste Journaux: Yes. I guess, yes. But, like, so when you go through Pluto you get to a possible ocean and at the bottom of the ocean it’s probably going to be around room temperature, but after you go below this you’ll probably hit, kind of, a rocky core probably, and this rocky core, actually the temperature will rise much faster. So once you get to the rocky core then it actually starts to become too high to be comfortable.

Leah Crane: You know how, like, fishing lakes are repopulated with fish? They basically have, like, the big cannon that they shoot salmon out of. It feels like we could do that in this situation.

Chelsea Whyte: With large whales?

Leah Crane: Just shoot a bunch of fish. If they’re not living at the bottom then they don’t even necessarily need to be whales, right? If they’re in that ocean, at the top of it.

Baptiste Journaux: Yes. I mean, the greater problem there is that you’re going to have to convince NASA that it’s a good idea in terms of what we call planetary protection. Have you heard of that?

Leah Crane: Mm. To turn Pluto into a big fish tank.

Chelsea Whyte: Yes, I don’t think they’re going to go for it.

Baptiste Journaux: It’s a little far. You know, it took us nine years with one of the fastest spacecrafts ever made, with New Horizons. That was launched in 2006 and it arrived in 2015, so it took us nine years and it was too fast to actually stop, so I’m not a huge believer in inter-planetary fishing.

Leah Crane: I think they’d all be dead by the time they got there. We’d have to create a salmon inter-generational spacecraft.

Chelsea Whyte: An inter-generational fish spaceship? What are you talking about? That sounds great.

Leah Crane: Go along then. You can be the fish queen.

Chelsea Whyte: My lifelong dream.

Leah Crane: You might just be a glorified aquarium technician.

Chelsea Whyte: Yeah okay, less good.

Leah Crane: And that’s our show, folks. Thank you to Konstantin and Baptiste for joining us today and, as always, a special thanks to our listeners.

Chelsea Whyte: And finally, if you have any cosmic object you want us to figure out how to destroy, let us know and it could be featured in a later episode of the podcast. Our email is [email protected].

Leah Crane: And if you enjoy our podcast, you might also enjoy my free monthly space newsletter, Launchpad. Check it out at newscientist.com/launchpad.

Chelsea Whyte: And if you just want to chat about this episode, or wrecking the cosmos in general, you can find us in Twitter @chelswhyte or @DownHereOnEarth.

Leah Crane: Thanks for joining us.

Chelsea Whyte: Bye.

Baptiste Journaux: First, we don’t know if there is an ocean so these poor salmons are going to get thrown onto a frozen surface, you’re going to end up with a bunch of frozen salmon. And we know how to do that, you know, it’s already something we know how to do.

Topics:

Source link

#drill #hole #straight #planet