What-if 0153: "Hide the Atmosphere"

[Zinho]

Earth’s atmosphere is really thin compared to the radius of the Earth. How big a hole do I need to dig before people suffocate?

—Sam Burke

The excavation would be a near-impossible challenge. But if you somehow solved all the countless engineering problems, you could—in principle—fit the entire liquified atmosphere of the Earth in a 5-mile-deep hole roughly the size of Texas.

Although you may not want to use that particular state.

Spoiler:

There are much worse movies Randall could have used as a reference; if the movie A Crack in the World were correct we wouldn't be able to dig through to the mantle at all, let alone to the core.

[Paradoxica]

It's just an engineering problem, right? Surely this specific what-if is feasable, if economically impractical.

[pogrmman]

I like this one, but I think I liked the other 153 better.

Also, where is citation 1 in this one? It starts at 2...

[Pfhorrest]

What if we were to water-cool it by draining the oceans into the hole too? Dig a hole deep enough to contain the atmosphere (accounting for compression with depth but ignoring the heating we're about to circumvent), and then dig it a little wider and deeper, and dig it in the middle of the ocean so that it fills with water, which then convects away the heat into the world's oceans. Build an enormous double-walled cup with the volume you need to contain the atmosphere (with vacuum between the double walls, like a thermos), and plunge that down into your water-filled hole, sucking the atmosphere down into it as you do so. Would the inside of your thermos remain cool enough, thanks to the vacuum and the water-cooling, to keep the atmosphere cool enough not to expand and spill out again?

[ConMan]

Am I allowed to ask what happened to reference number 1?

[Soupspoon]

Am I allowed to ask what happened to reference number 1?

You are number 6...

[Znirk]

So what is the texas request reference? (Yes, I know, try for yourself first; but this specific question doesn't seem particularly googlable.)

[Mikeski]

Maybe reference 1 was to Lebowski, pointing out that you can't dig holes that big without gravity filling them in by pulling the planet back into a mostly-spherical shape? (Which he then removed when he remembered that Lebowski didn't have a mantle, and you couldn't dig a really deep hole like that on Earth anyway...)

[Mikeski]

So what is the texas request reference? (Yes, I know, try for yourself first; but this specific question doesn't seem particularly googlable.)

"Don't Mess With Texas." (356,000 hits on Bing.) It started as an anti-littering slogan, but it went viral, about 30 years before memes were said to "go viral".

[Flumble]

Secondary problem: where do we leave all the excavated rock? How high a mountain can we construct with that much rock?

Am I allowed to ask what happened to reference number 1?

You are number 6...

Get with the times: we are number one.

[Silhalnor]

Ok, so a hole the size of the US would have to be too deep. So why don't we just dig up the entire Earth a few miles deep?

Oh! Right! The dirt! We'll just fire that up into space. Yes. We'll put it all in orbit. Then all the air will be "underground." Or at the very least "under some ground."

[david.windsor]

So what is the texas request reference? (Yes, I know, try for yourself first; but this specific question doesn't seem particularly googlable.)

"Don't Mess With Texas." (356,000 hits on Bing.) It started as an anti-littering slogan, but it went viral, about 30 years before memes were said to "go viral".

Oh, that's ok then, we'll pickup all the litter when we dig the hole.

[thunk]

Calculations in this paper⁠[6] show that temperature gradients of more than about 30°C per kilometer will result in no compression at all. If the temperature change is faster than that—as is common in areas with thin crust or volcanic activity—the density of air will actually drop as you go deeper, even as the pressure increases.

If you do actually manage to exceed the autoconvective lapse rate of 34.14 K/km, then the less-dense air on the bottom would rise. This would case a bad mess of convection and take the heat away until (I guess) things may get approximately adiabatic (or if you managed to somehow suppress convection, isochoric?) I'm really not sure. In the latter case, you still wouldn't be able to fit more air into the hole.

On the minus side, you still have superheated air coming out of the hole, which will indeed make people mad at you.

[pogrmman]

Am I allowed to ask what happened to reference number 1?

Looks like it is fixed

[suso]

Let's take this further. Assuming this is an orthographic projection and those people aren't communicating via radio, those people are 107 miles tall and can't hear each other because there is no longer an atmosphere.

Perhaps related: https://what-if.xkcd.com/77/

[Silhalnor]

There are surprisingly few posts here. Didn't this forum use to be more active last time I was here... quite possibly a year ago?

[Scott Auld]

Worth the wait.

[Scott Auld]

There are surprisingly few posts here. Didn't this forum use to be more active last time I was here... quite possibly a year ago?

Killed by Time.

[suso]

There are surprisingly few posts here. Didn't this forum use to be more active last time I was here... quite possibly a year ago?

We were waiting for you to come back. Good to see you again.

[rmsgrey]

There are surprisingly few posts here. Didn't this forum use to be more active last time I was here... quite possibly a year ago?

What If... Randall stopped posting new What If?s for a few months?

[KittenKaboodle]

I know the question was about "digging a hole" but if one is going to compress the atmosphere into SCUBA tanks, wouldn't it be easier to just throw them into the ocean? If the goal is to suffocate everyone, drowning is perhaps somewhat similar so the rising (faster) sea level caused by the displacement is sort of helping the end goal.

BTW; if there is no atmosphere, there is no greenhouse effect, I bet one could significantly reduce temperature of the planet long before every one suffocated.

[Agent K]

There's a little typo in the archive-section. It says 153 was posted on "January 30, 2016". Happens to me every year too, sometimes til easter.

[mathmannix]

Why would someone in New Mexico care if you messed with Texas? (If anything, I would think they would approve.)

[Mikeski]

Why would someone in New Mexico care if you messed with Texas? (If anything, I would think they would approve.)

Obviously, that's a traveling Texan returning home: "WE specifically requested..."

Had he been there when the excavation began, you would have had to mess with him, first.

So the important question is "Why was Texas down to a population of one?" There doesn't seem to be much point in suffocating the rest of life on earth if things were already that bad...

[Pfhorrest]

It's not down to a population of one, those enormous people towering over the countryside are composite beings made up of the entire populations of Texas and, uh... Florida maybe? That's the closest state by population to Texas.

[KarenRei]

As some side trivia, "freezing out the atmosphere" is a serious proposition for terraforming Venus. Big sunshade, freeze it out steadily, let it concentrate in the lowpoints (which deepen from the weight), manualy assist with concentrating the rest, then pave over it with insulation and cooling.

I'd argue that with enough insulation, the cooling isn't needed. Because if you're growing plants, they're going to make oxygen, which is going to be consumed by rusting Venus's large amounts of crustal FeO. The plants in turn will die and slowly sequester the carbon. The reduction in temperatures would also allow for the formation of carbonate minerals. So you actually need some steady rate of leakage, at least until you exhaust the planet's buffers.

[Silhalnor]

There are surprisingly few posts here. Didn't this forum use to be more active last time I was here... quite possibly a year ago?

Killed by Time.

Pff, fun pun! So that thread's still going?

We were waiting for you to come back. Good to see you again.

At first I assumed this to just be entirely sarcasm but you know what, I think I actually recognize your name, so... I don't know, haha!

What If... Randall stopped posting new What If?s for a few months?

Then be excited that there's finally a new one! I know I kinda sorta wasn't actually. Plus the update proved to be kinda disappointing. Personally, I'd like to see more weird concepts created by combining units. Like measuring fuel expenditure in square meters! I can't seem to find that one now, though...

[Scott Auld]

Like measuring fuel expenditure in square meters! I can't seem to find that one now, though...

Maybe it's https://what-if.xkcd.com/11/ ?

[glego73]

Disappointed with this one......the question is great but the answer left me cold.

At what point would we all suffocate? When the atmospheric pressure is so low at sea level that it is equivalent to being above the 'dead zone' on Everest - you don't have to get all of the atmosphere into the hole.

Air pressure only goes up as you go down your hole due to the weight of the air above it - it is not just a matter of the depth of the hole but also the shape of it. A narrow deep hole will store more air than a shallow wide hole of the same volume. There is also the fact that as the air floods into the hole there is less atmosphere above, so the pressure in the hole will go down.....

[ftb47]

This needs a revisit.

The question wasn't how deep does it need to be to get rid of all the air, the question was how deep does it need to be to suffocate everybody. I suspect a much smaller hole is needed for that.

[Soupspoon]

How does the trapezoid (or inverted truncated cone/pyramid/whatever) nature of the hole affect things? Probably not that much, given the insignificant thickness of the lithosphere we are allowed to cut through meaning even a wide shallow hole has only marginally converging 'vertical' edges in the grand scheme of things, and a hypothetical narrow-but-deep solution has less solid-angle (thus more gradual convergence, if more towards-a-point because of depth), so an in-the-head juggling of factors seems to make it not more significant than the composite P₁V₁/T₁=P₂V₂/T₂ effects...

That's before practical engineering¹ demands that hole-sides are non-vertical for reasons of preventing slumping inward, unless unobtanium-lining can be employed as (locally) vertical shoring...

¹ Practical engineering? In a What-If? Sorry, don't know what I was thinking...

[KittenKaboodle]

That's before practical engineering¹ demands that hole-sides are non-vertical for reasons of preventing slumping inward, unless unobtanium-lining can be employed as (locally) vertical shoring...

¹ Practical engineering? In a What-If? Sorry, don't know what I was thinking...

Even in What-if vertical hole sides have problems: https://what-if.xkcd.com/46/

[cellocgw]

Just [not actually] thinking,...
and glad to see that what-if is not yet quite pining for the fjords,

But all this digging and cooling seems like a lot of work. I propose an alternative method of getting rid of the atmosphere: use a massively parallel installation of those new quantum vacuum thrusters mounted off-vertical to increase the Earth's rotational speed until all the atmosphere is spun off into space.
We could call it the "cotton-candy effect" or something.

[Silhalnor]

This needs a revisit.

The question wasn't how deep does it need to be to get rid of all the air, the question was how deep does it need to be to suffocate everybody. I suspect a much smaller hole is needed for that.

Good point!

A "hole" is really just an emptying of a patch of space. If the goal is to suffocate everyone on Earth with a hole while minimizing its de-filling volume... Reframe the question and you start to realize that there are actually quite a lot of options.

First, note that the question doesn't specify that the hole must be on Earth. Maybe we can carve a small hole into the Sun's core and make it go nova. But no, the hole would be far bigger than what we'd need on Earth (I assume). Plus, the people wouldn't suffocate. They'd disintegrate. But, if we could somehow halt fusion without vaporizing everyone back home then Earth's floral life will die off. (Eventually. After the Sun cools down.) After that, it's simply a matter of waiting for the oxygen levels to drop.

We also might be able to put a hole in spacetime and trigger vacuum decay... but that presents the same problem. Namely, no one has the time to be dying of suffocation.

What if we make a wormhole? That's a 'hole', right? Put one end on Earth and the other someplace else.

Or, going further, what if we allow multiple holes? I'm envisioning proton sized holes here—one for each oxygen atom in the atmosphere. Just one. Just enough to transmute our oxygen supply into asphyxiating nitrogen. Of course, once we start dealing with subatomic particles our sense of "size" becomes a bit fuzzy, especially since the goal is to use the smallest size possible... If we make the hole too small to encompass the proton, does the proton "pop out"? Or do we get "half a proton"?

Well, never mind all that. There's a much easier way to suffocate everyone by punching holes in places they don't belong. Instead of removing the entire atmosphere, let's just remove everyone's lungs. It is surprisingly difficult to find the average lung volume—as opposed to air capacity—so I am just going to assume each lung to be roughly the size of a human heart. That's 70 millilitres. Given two of those for each human on Earth, Wolfram Alpha gives me a bit more than one billion litres, or a giant cube the length of a football/soccer field.

Much easier.

Wolfram Alpha also tells me that this is equivalent to 1.01 trillion square-persons cubic-meters. I'm not too sure what that's supposed to mean, unfortunately. Presumably a quirk of how populations are encoded.
http://www.wolframalpha.com/input/?i=70+ml+*+human+population+*+2

Edit: A cubic football/soccer field packed full of human lungs (what a mental image, that) almost seems too small to hold the global lung supply. Does this seem too small to anyone else, or is it about right and I'm just overestimating what 7.2 billion people means? (Or perhaps I'm underestimating the sheer scale of a sports field.)

Like measuring fuel expenditure in square meters! I can't seem to find that one now, though...

Maybe it's https://what-if.xkcd.com/11/ ?

Ah! Yes. Thanks! I loved that insight.

[dasberg]

This what if seems to have been completed hastily, or for some other reason, without the usual near-obsessive completeness. The question asks how big of a hole would it take to get people (on the surface) to suffocate.

The first basic answer: too big of one... So we need to compress the air in the hole better.

It mentions that we only need to remove 65% of the atmosphere before people can't breathe and suffocate, but then utilizes the full atmosphere in all calculations.

Also, what if we selected which parts of the atmosphere to remove, like say, just the oxygen? We'd probably have to remove all of it, and at a rate faster than the plants could replace, but that is potentially less of a hole.

[rmsgrey]

Or, going further, what if we allow multiple holes? I'm envisioning proton sized holes here—one for each oxygen atom in the atmosphere. Just one. Just enough to transmute our oxygen supply into asphyxiating nitrogen. Of course, once we start dealing with subatomic particles our sense of "size" becomes a bit fuzzy, especially since the goal is to use the smallest size possible... If we make the hole too small to encompass the proton, does the proton "pop out"? Or do we get "half a proton"?

Well, never mind all that. There's a much easier way to suffocate everyone by punching holes in places they don't belong. Instead of removing the entire atmosphere, let's just remove everyone's lungs. It is surprisingly difficult to find the average lung volume—as opposed to air capacity—so I am just going to assume each lung to be roughly the size of a human heart. That's 70 millilitres. Given two of those for each human on Earth, Wolfram Alpha gives me a bit more than one billion litres, or a giant cube the length of a football/soccer field.

Much easier.

Wolfram Alpha also tells me that this is equivalent to 1.01 trillion square-persons cubic-meters. I'm not too sure what that's supposed to mean, unfortunately. Presumably a quirk of how populations are encoded.
http://www.wolframalpha.com/input/?i=70+ml+*+human+population+*+2

Edit: A cubic football/soccer field packed full of human lungs (what a mental image, that) almost seems too small to hold the global lung supply. Does this seem too small to anyone else, or is it about right and I'm just overestimating what 7.2 billion people means? (Or perhaps I'm underestimating the sheer scale of a sports field.)

A) Atomic nuclei don't contain protons and neutrons (well, H₁'s nucleus is a lone proton) but rather a sort of quark soup. It's only when you pull some of the quarks out that they group into protons and neutrons (and assorted mesons and other exotic particles) so you'd have to pull out three quarks rather than one proton...

B) Maybe my google-fu is stronger than yours, but, while I didn't turn up helpful numbers, I found sources that say a human heart is around the size of a fist, while a lung is around the size of a football (I'm guessing american football) - which puts you off by at least half an order of magnitude...

[Silhalnor]

A) Atomic nuclei don't contain protons and neutrons (well, H₁'s nucleus is a lone proton) but rather a sort of quark soup. It's only when you pull some of the quarks out that they group into protons and neutrons (and assorted mesons and other exotic particles) so you'd have to pull out three quarks rather than one proton...

B) Maybe my google-fu is stronger than yours, but, while I didn't turn up helpful numbers, I found sources that say a human heart is around the size of a fist, while a lung is around the size of a football (I'm guessing american football) - which puts you off by at least half an order of magnitude...

A) You mean my teachers lied to me? Inconceivable!
Seriously, though. All my readings on physics and I have never heard of this? Do you have a source? If protons and neutrons aren't 'real' then my ignorance on that is mildly disturbing.

B) It's quite possible that you're better at tracking stuff down since this situation has happened to me before... Then again, I was also weeding out a lot of sources because they might have been including the lung's volume when including the air inside of it, which I didn't want. Never saw the football comparison, though...

Also, after writing that, I have realized that this thread has thousands of views! Eep. Maybe I should've put more work into that analysis.

Oh well. Better than not posting my random analyses at all, I suppose? I've done this a few times before and just never told anyone, haha.

[Pfhorrest]

If protons and neutrons aren't 'real' then my ignorance on that is mildly disturbing.

They are real, but they don't retain separate identities when bound together in nuclei.

It's like how several atoms bound together into a molecule often share electrons. The electrons don't belong to just one atom or another anymore, they belong to the molecule, even though the original separate atoms definitely owned their specific electrons beforehand. In a way, the atoms have kinda lost their original identities (though they still have separate nuclei, at least).

(Actually I recall a chemistry teacher one year being vehemently insistent that the statement "calcium carbonate contains calcium" is just patently false; it contains calcium ions, which are not whole calcium atoms. To prove his point, he dropped a small bit of calcium into water which made notable pyrotechnics, then dropped a piece of calcium carbonate (chalk) into water and... nothing. Why wouldn't it do the same thing if there was calcium in there?)

Likewise, when several nucleons (protons and neutrons) get bound together into an atomic nuclei, their quarks cease to be uniquely confined into protons and neutrons. Rather, all the quarks that made them up get mixed together with a bunch of gluons to make a kind of new giant super-nucleon, the nucleus. Which takes less energy to hold together than the separate nucleons did in aggregate, which is why you get energy out of fusion. And you have to put that energy back into it to those quarks out into separate particles again. (Until you get to large enough nuclei, which then start to fall apart of their own accord, spitting quarks back out automatically, which then must bond together into nucleons again because color confinement).

[cryptoengineer]

When I saw "Star Wars: The Force Begins", I was struck by exactly this question. The film includes

Spoiler:

an entire planet which has been converted into a hyper Death Star, including a trench which must be hundreds of miles deep and hundreds of miles across. Quite aside from the 'engineering problems', the planets entire atmosphere should have collected in the bottom of the trench, leaving the surface in vacuum. Yet it is shown with atmosphere, and lush vegetation

[Soupspoon]

An inverse (i.e. equal, just functionally backwards) version of the docking bay atmospheric force-fields on starships?

And the average width is not necessarily that wide.

(Shorn of understandable spoilers.)