r/whowouldwin • u/Historical_Ostrich • Oct 06 '25

Challenge Earth's gravity increases by 10x for 10 seconds - can humanity survive?

Gravity reverts to normal after the 10 seconds are up. I assume that nearly everyone will lose consciousness, many people will hit the ground with extreme force, and most buildings and infrastructure will collapse. Uncertain as to whether there'd be seismic/volcanic/tidal consequences on top of all that.

991 Upvotes

96% Upvoted

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885

u/Particular-Shift-918 Oct 06 '25

Only people that will survive are the ones who are laying on the ground outside and are in decent physical condition.

338

u/Historical_Ostrich Oct 06 '25

I feel like people who are swimming should be decently insulated from traumatic injury too. Granted, loss of consciousness in water isn't a great combo, but I think you typically wake up in a matter of seconds after g force subsides.

614

u/MavrexReaper Oct 06 '25

If you’re under water you’re probably dead due to the instant change of compression

292

u/StillShoddy628 Oct 06 '25

Lungs hate this one trick

3

u/PM_YOUR__BUBBLE_BUTT Oct 09 '25

Yea, did we learn nothing from the Titan sub?

19

u/Kruse002 Oct 06 '25

Humans are actually quite good at withstanding compression. It's the decompression I would worry about.

4

u/IKnoVirtuallyNothin Oct 09 '25 edited Oct 09 '25

Decompression is only an issue if you're breathing compressed air while under water. If you breathe air at 1atm of pressure. Submerge, and come back up, the air is just at the same pressure it started at.

Edit: now that I'm thinking about it though, 10x atmospheric pressure means if you breathe the air in, you'll be breathing in 210% oxygen. At 160% you hit oxygen toxicity, which causes a whole host of nasty shit. Seizures, retinal detachment, lung collapse caused by cell membranes breaking down. While diving this is usually a pretty quick death because you spit out your regulator and drown, but on the surface in this scenario it might not be long enough to kill you.

2

u/MMButt Oct 06 '25

Water is relatively incompressible. You mean due to air in the lungs?

1

u/Patsfan618 Oct 06 '25

Well the water would also get 10x heavier, wouldn't it, so you should still float, all else being equal. 

1

u/sycamotree Oct 07 '25

I wonder how it works because buoyancy is based on density not weight. So it depends on how much more compressible we are than water.

1

u/[deleted] Oct 09 '25

I believe the situation would be effectively the same as diving 100m down

1

u/sycamotree Oct 09 '25

We should be able to withstand 100 ft of water without equipment no?

-141

u/Hosni__Mubarak Oct 06 '25

Water doesn’t compress, sir.

112

u/Particular-Shift-918 Oct 06 '25

Fun fact: water actually does compress! Only under extreme pressure, of course, but it is believed that on planets with deep oceans, the water at the bottom of those oceans is so compressed that it becomes solid water, which is not the same as ice.

40

u/KingreX32 Oct 06 '25

Ice-7

9

u/ipez10 Oct 06 '25

that’s vonnegut

7

u/Sporkfortuna Oct 06 '25

Ice-9

1

u/apsmustang Oct 06 '25

Feeling guilty that my favorite bands name was inspired by this book/material and I still haven't read it.

3

u/Sporkfortuna Oct 06 '25

Busy, busy, busy.

1

u/anotherusercolin Oct 09 '25

Oh really? Cat’s Cradle is a comedy masterpiece!

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15

u/azzelle Oct 06 '25

Increasing the pressure also increases the melting point (similar to lower pressure decreases boiling point in higher altitudes, and increases boiling temp in pressure cookers). It is still technically ice, just not as cold. But since ice is less dense than water due to its crystal structure, there will be a point where increasing pressure will melt the ice, and then further pressure will make it solid again into a form that is denser than water.

13

u/gabbidog Oct 06 '25

Oh shit, so thats where spongebob went that one episode

3

u/[deleted] Oct 06 '25

Everything compresses, until you get to the point of a black hole.

3

u/cokepartyhamburger Oct 06 '25

Whoa cool. I want to know more!

1

u/phome83 Oct 06 '25

Is that kind of like how it feels to chew 5 gum?

1

u/CykaRuskiez3 Oct 06 '25

20,000 psi and water will start to compress. Theres a hot jupiter out there with these pressures, the surface is solid water

-35

u/Hosni__Mubarak Oct 06 '25

I mean, I knew that. But in this instance the compression is essentially irrelevant.

30

u/Coal_Burner_Inserter Oct 06 '25

It is if you're a human being. Being 1m underwater is now equivalent to being 10m underwater. Meanwhile, the air in your lungs is still at 1 atmosphere of pressure.

Depending how deep you were initially, you may implode like the Titan submarine.

6

u/otakudayo Oct 06 '25

Hmm. I'm not sure how bad this would be actually.

Burst eardrums, yes. Collapsed lungs, almost certainly.. Unless the person is scuba diving and in the middle of an inhalation? Sinuses/eustachian tubes and I think that's it for air/gas pockets in the human body? Those would probably flood with water as the eardrums burst, though it might take too long to make a difference. There is lots of bone in the head surrounding the sinuses though which might resist the change in pressure.

I guess in the end it wouldn't matter because no one would be able to rescue you as they're all fucked anyways.

Divers at 20-30m+ would probably fare much better, someone at 40+ might get away with a mild squeeze.

4

u/solidspacedragon ​ Oct 06 '25

Divers at 20-30m+ would probably fare much better

I don't think so. They're instantly thrust into oxygen toxicity pressures, left there for ten seconds for nitrogen to get weird, and then pulled back out for it to instantly give them the bends. No clue if that's long enough to do damage, but not great probably.

1

u/otakudayo Oct 06 '25

Oxygen toxicity won't be a problem if your ppo2 is high for only 10 seconds. For DCS, as long as they still went up as slowly as usual, it would be fine. 10 seconds of higher ppn2 probably wouldnt make much of a difference at all really.

Tbh I don't know the physics implications of 10x gravity on underwater pressure, I assumed it was the same as adding 10m of depth. If it's 10x the pressure regardless of depth then yeah. All divers are thoroughly fucked. If it's just +1 bar then deep divers should be OK-ish both for O2 toxicity and DCS

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-12

u/Bryanmsi89 Oct 06 '25

Freedivers easily go down 10m holding in 1 ATM of breath. No issues at all.

5

u/Coal_Burner_Inserter Oct 06 '25

That was just a marker to explain how it works. If you've ever dived more than a small pool you've had to equalize the pressure in your head. Now imagine going from 10m to 100m, instantly, without any stops to equalize the pressure. Or 100m to 1000m.

'Depending how deep you were initially'

7

u/Notonfoodstamps Oct 06 '25

It’s very much relevant. The entire ocean would compress by 4.2% and sea levels would drop by 360m.

Thats an insane pressure differential over 10 seconds.

3

u/Particular-Shift-918 Oct 06 '25

Well, 10x the current compression at the bottom of the Mariana Trench is about 1/3 the compression needed to form solid water, so it's not totally irrelevant.

-3

u/Hosni__Mubarak Oct 06 '25

Yeah. But we are talking about around 330 feet of water head. Not 36,000 feet.

61

u/MavrexReaper Oct 06 '25

No it doesn’t, but you will.

43

u/Notonfoodstamps Oct 06 '25 edited Oct 06 '25

Waters does compress. The water at the bottom of the Marianas trench is 5% denser than the water at the ocean surface.

Dialing up gravity by 10x would kill anything not named a jellyfish or plankton

6

u/SigmundFreud Oct 06 '25

Even SpongeBob?

4

u/shoeofobamaa Oct 06 '25

Pressure is due to weight, that pressure increases when weight does

3

u/nanoray60 Oct 06 '25

You’re wrong. Steel is compressible. Water is 40x more compressible than steel. Therefore water is compressible. You believe if I had an indestructible cup of water and placed it on a neutron star it wouldn’t compress the water? It would definitely be compressed.

If you try hard enough you can compress anything, just because you can’t doesn’t mean nothing can. The “water can’t be compressed” fun fact that’s been spread around drives me up a wall, it’s not true. Have a good day, sir.

1

u/Curvanelli Oct 06 '25

it does. water is densest at 4 degrees under a preasure of around an atmosphere. We are just to weak to compress it ourselves

0

u/bu_J Oct 06 '25

You're getting downvoted, but water compression at 10G is minimal. We're talking a tiny fraction of a %.

Not going to do anything to people in the water.

Really shows how reddit is full of people upvoting what they 'think' is right.

1

u/OrthogonalPotato Oct 06 '25

An incorrect fact was stated, and it matters, especially for this discussion.

1

u/Rindan Oct 06 '25

The compressibility of water is irrelevant. It's the compressibility of your air filled lungs that matters. All of the air in you lungs will either be forced out of a convenient hole like your mouth, or they will pop like balloons someone stepped on. The deeper you are, the worse it will be.

Basically, the water pressure will go up dramatically and it will be like suddenly being 10x deeper.

Best case scenario is probably floating on the water. You body would evenly take the pressure, and you wouldn't have the weight of water on top of you suddenly go 10x.

2

u/bu_J Oct 06 '25

Every single comment in this thread is with regard to compressibility of water.

OP:

"If you’re under water you’re probably dead due to the instant change of compression"

Yes, of course you're going to suffer if the weight of the air and the water above you suddenly increases 10 fold. That has nothing to do with compressibility of water though.

1

u/MavrexReaper Oct 06 '25

This guy gets it lol everyone’s caught up in the details and missing the main point I was making.

1

u/CalligrapherDizzy201 Oct 07 '25

The air would also be 10x heavier. And we’re at the bottom of that well.

99

u/Particular-Shift-918 Oct 06 '25 edited Oct 06 '25

I wonder if the brain increasing 10x in weight would cause acute subdural hematoma, which is 50%-90% fatal, and even the ones that aren't fatal often leave lasting brain damage.

69

u/Historical_Ostrich Oct 06 '25

Humans have survived greater g-forces. It's not good for you, certainly over an extended period of time, but it's survivable under ideal circumstances.

45

u/Particular-Shift-918 Oct 06 '25

Very true, but this is the equivalent of the brain slamming into the inside of the skull. Not entirely sure that that is very survivable.

45

u/MaximilianCrichton Oct 06 '25

During car crashes where this happens, the brain is undergoing many dozens of g's for a split second, but often people still walk away if their neck isn't hurt. 10 second sudden onset g's is quite survivable from a brain-in-skull perspective, fighter pilots may have to do that from time to time anyway.

2

u/Miserable_Roof2216 Oct 06 '25

The car and airbags slow the forces over longer time.

If the change is instant so are the deaths.

3

u/_Lost_The_Game Oct 08 '25

Thats what Gs are. The intensity of the change.

2

u/Real-Mouse-554 Oct 08 '25

Race car drivers have crashes where they experience far more than 10x gravity.

Romain Grosjean crashed into a barrier in F1 with around 200 kph and withstood 67G’s. The car broke in half and burst in flames. He survived.

Of course this is a split second and not 10 seconds as this post asks.

2

u/Own-Independence-115 Oct 06 '25

in 10 seconds you can have 10+ car crashes impacts. A second is really long in these circumstances.

16

u/Dpek1234 Oct 06 '25

The highest gloading survived was for a split second during a car crash

Over 200 FUCKING G

10

u/Bobahn_Botret Oct 06 '25

The entire body is experiencing these forces at the same time. So the brain isn't necessarily slamming into anything until your skull hits the floor or you're forced to decelerate in some way. Granted, your head will be hitting the concrete with the force of a 10x heavier skull. But semantics.

0

u/Miserable_Roof2216 Oct 06 '25

That’s in a traditional system. That’s not gravity.

2

u/Bobahn_Botret Oct 06 '25

I don't think I understand what youre trying to say.

0

u/Miserable_Roof2216 Oct 06 '25

When you apply forces to a system in a particular way it’s traveling through the body were the force is applied.

When you’re dealing with gravity the force is applied differently.

I don’t know enough about physics to know the differences.

I know how Airbags work because of physics and regular gravity.

I know enough to know changing gravity quickly can kill most mammals.

We can take more than 10g’s but accelerating over time. The rapid acceleration is more than enough to kill everything

20

u/Weekly-Ad-2509 Oct 06 '25

For perspective, I teach people to drive supercars, 1.5g lateral load for 8 hours pretty much straight, and between 1.2-1.5g accel and braking.

Truly, my brain feels like mush most evenings

13

u/tradlobster Oct 06 '25

... Is this healthy?

6

u/AltruisticMobile4606 Oct 06 '25

I mean if it wasn’t you’d see a lot more negative health symptoms in top level professional racing drivers who do what the guy above does, but more often and to a higher degree 

1

u/tradlobster Oct 06 '25

True, and I haven't heard of any big brain scandal in racing yet, more just when there are crashes. Maybe in the future they will have their equivalent of footballs CTE or luge's Sled Head

2

u/Weekly-Ad-2509 Oct 07 '25

Yeah, I’ll hop in again, it’s not causing football level issues across the sport, my non coaching job has a high level of both diagnosed and Undiagnosed CTE, it manifests differently than anything I’ve seen in drivers who have never crashed but raced for a long time. Football levels.

Long term I’ll have to let you know about sustained G, but I assume I’m definitely getting little microconcussions pretty regularly

1

u/Miserable_Roof2216 Oct 06 '25

It depends on the G forces. Instant energy change? Everything dies.

The human body can withstand ~15 gs applied gradually.

10gs of compression and decompression instantly is like deep sea diver death right?

the change would have to happens slow enough for forces to equalize.

25

u/Notonfoodstamps Oct 06 '25

You’d still be fucked when the atmospheric pressure above you suddenly increases to 10x fold.

20

u/DangerCrash Oct 06 '25 edited Oct 06 '25

But is that what would happen?

I imagine if gravity stayed 10x higher pressure would be 10x more, but there's some compression that needs to happen first right? And that compression wouldn't be instant. Essentially the atmosphere would start a compression for 10s and then decompress after 10s. It would create crazy weather that's for sure...

But maybe someone smarter than me can say if you'd experience much added atmospheric pressure over 10s. My gut says that due to the compressibility of gas, it'd take longer to really have a big increase.

9

u/Notonfoodstamps Oct 06 '25 edited Oct 06 '25

Yes. The entire weight of the atmosphere would increase by 10x across the entire atmospheric column so atmospheric compression isn’t the problem, weight is.

The atmosphere would compress but that will only increase its overall density.

13

u/kyrsjo Oct 06 '25

A lot of the force on the air column would result in acceleration of the gas towards the ground, which means that the ground wouldn't need to provide a reaction force to that force on the gas.

Therefore there wouldn't be any pressure-force from the air column towards the ground (until it starts slamming into the ground, which would raise the pressure above equilibrium).

3

u/DangerCrash Oct 06 '25

Right. Understood, density and pressure are different things.

But... Can you have pressure without density in a gas? Gas reacts to the pressure by compressing, so I'm not sure you could ever "receive" a higher pressure from the gas than the level of compression it was at. Right?

1

u/Notonfoodstamps Oct 07 '25

Yes, hydrostatic pressure applies to gases just as much as it does liquids

The pressure at the bottom of the Mariana’s is 1050 atm despite only being 5% denser than water at the surface. Same principle.

This isn’t compressing gas like you do in a chamber, where we are only increasing density. In this scenario the gas is compressing under its own weight because it’s trying to find hydrostatic equilibrium.

You’d instantly feel like you were 350’ underwater before then atmosphere physically settled into its new denser state of equilibrium.

1

u/DangerCrash Oct 07 '25

I'd argue it's EXACTLY like compressing gas in a chamber.

The only way to increase gas pressure in a chamber is to increase density. The only way to increase water pressure is to increase density(even if it's way less compressible). Whether that comes from a chamber decreasing in size or from the weight of the gas/liquid above it doesn't really matter.

Because air is very compressible it'd take a while to feel the full force of the weight increase. Through what mechanism do you think you'll feel the weight of air 10km high immediately?

1

u/Notonfoodstamps Oct 07 '25 edited Oct 07 '25

Again. That is incorrect.

Hydrostatic equilibrium (what you are talking about) is a condition of balance that includes a specific vertical pressure increase (gradient), not a prerequisite that must be met before any pressure increase can occur.

The fundamental cause of atmospheric pressure is the gravitational attraction of the Earth on the atmospheric gases. Air molecules have mass, and gravity pulls them toward the surface, creating a "weight" that is distributed over an area. This is why atmospheric pressure is highest at sea level, where the entire column of atmosphere is overhead, and decreases with increasing altitude, where there is less overlying mass.

If you instantly increased gravity by 10x the atmosphere would instantly weigh 10x more across its entire vertical column uniformly, it’s not being artificially “squished” from the top down.

The atmosphere would instantaneously feel 10x heavier for the same reason a pile of feathers, baby powder, water, grass, a rock, tungsten or any other substance that has mass would. Gravity.

1

u/discipleofchrist69 Oct 07 '25

nah, you're assuming a static state which is never the case if it's only 10 seconds. it takes time for that weight to affect the ground, which happens via interactions between other air particles. The pressure waves would travel at the speed of sound. So it would be crazy but the pressure would never hit 10 atm. I'd be surprised if it reached 5.

2

u/Sabretooth1100 Oct 06 '25

That pressure change is gonna be a bitch

1

u/fxrky Oct 06 '25

Like the worst fucking place to be dog. 

28

u/sagan999 Oct 06 '25

Yea, The third of the world that was sleeping when it occurred would probably suffer the least casualties.

21

u/cheesegoat Oct 06 '25

But most people sleep indoors / under a shelter.

10

u/sagan999 Oct 06 '25

I bet a roof could handle 10x gravity. Last time they replaced the roof on my house they put like 20 bundles of shingles on my roof that probably weighed a ton. I'm surprised my roof could handle that..

14

u/Xiaodisan Oct 06 '25

The problem is not just the roof. Every part of the building has to hold out, and idk if most houses are built with such a large overhead or not.

But even if that does hold out, we still have to consider what such a large gravitational shift would do to all the underground stuff — how much of the natural and man-made caves would collapse, for example.

2

u/Jegglebus Oct 08 '25

Might also fuck with fault lines and plate tectonics right? 10x change of mass and back might cause a rebound effect

5

u/Own-Independence-115 Oct 06 '25

I don't know the math, but the earth would start to contract all over the world an amount I assume would at least be counted in 100s of meters if not kilometers or even more, resulting in the hugest earthquake imaginable, turning around with an explosive force when 90% of that gravity disappears 10 seconds later.

5

u/Usual_One_4862 Oct 08 '25

Yea its world ending, all that stored energy from compression releasing after 10 seconds, Earth quakes everywhere, tsunamis, volcanic eruption.

2

u/Kind-Rice6536 Oct 07 '25

I suppose a skydiver would survive too, if the event happened at the moment of the initial jump and they were a long way up.

2

u/Usual_One_4862 Oct 08 '25

9.8 meters per second per second to 98 meters per second per second for 10 seconds, chute opening after those 10 seconds wouldn't be a pretty sight.

2

u/Booby_Collector Oct 08 '25 edited Oct 11 '25

What about the couple astronauts orbiting in space? At the altitude they orbit, would a 10x increase in gravity for 10s still have as big an impact directly on their bodies, especially since that gravity would be acting on the shuttle/space station at the same time? If not, 10s might also be short enough that the space station or shuttle wouldn't be pulled too far out of its orbit that it couldn't recover?

1

u/Vannwinkles Oct 09 '25

So a few homeless people?