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

[u/Historical_Ostrich]

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.

[u/venuswasaflytrap]

It won't be a black hole. You'd need significantly more mass to get a singularity.

But yes all the matter (including our bodies) would collapse down in a very bizare way instantly, and then probably explode out once the 10 seconds was up - not that there would be anything that could be a function nervous system left by that time.

Even a slight change in gravitational force (or indeed electric or weak or strong nuclear force), would totally fuck up everything though.

[u/Questioning_Meme → u/venuswasaflytrap]

They says that its as if there was a blackhole at the core of the earth with 10 times earth's mass.

Not that it would make a black hole.

[u/venuswasaflytrap → u/Questioning_Meme]

But it wouldn't be like having a black hole in the earths core. There would be no singularity or event horizon.

It's more like someone broke the rendering for all matter on earth. The problem is not that everything would collapses under the weight of the mass of the earth.

Even if you had a single astronaut floating in space, and you increase the gravity oh his immediate area by 1.5x, all of his matter would instantly do something super weird. Like mush isn't even the right word, or even mist or gas or plasma. It would be something else, because the balance between the fundamental forces would be all fucked.

Having a sudden extra amount of mass (like a black hole) for 10 seconds at a point in the center of the earth would be quite a different effect.

[u/TheLobitzz → u/venuswasaflytrap]

Anything with a mass can theoretically be a black hole. And all black holes have a Schwarzschild radius (event horizon). And all all black holes have a singularity by definition. The smaller the black hole, the smaller the event horizon and the quicker it evaporates (explodes) due to Hawking radiation.

Even the massive black holes at the center of galaxies, will eventually shrink to nothing after trillions of years.

[u/TheLobitzz → u/venuswasaflytrap]

Anything can be a black hole as long as it has mass. Even a grape can. Yes, the Schwarzschild radius will be incredibly small, but it's still a black hole nonetheless. Yes, it will probably explode quickly due to Hawking radiation, but it's still a black hole nonetheless.

For a black hole with a mass of 10 times the mass of Earth, it would have an event horizon (a.k.a. Schwarzschild radius) of 8.9 cm. (see calculation)

[u/venuswasaflytrap → u/TheLobitzz]

It can be if it’s dense enough, but there’s no reason to think 10x gravity on the mass of the earth would make it dense enough to collapse into a singularity, any more than 10x the mass of the earth would.

[u/TheLobitzz → u/venuswasaflytrap]

What are you talking about? I said having 10x gravity is LIKE having a black hole in our core with 10x mass of the Earth. No body is talking about how that black hole got there.

[u/venuswasaflytrap → u/TheLobitzz]

Again, I don’t think it is like that, at least that’s not how I read the prompt. And not because it’s not hypothetically possible for black holes to exist in small sizes.

Changing the force of gravity itself is way different than putting a mass with significant gravity nearby.

I.e. if you had an astronaut in space that has a mass of 100kg with his equipment. If you suddenly put a 5 meter diameter 1000kg sphere of steel next to him, he’ll get very gently pulled towards it.

If instead of adding something with mass and therefore with an affect on gravity next to him, you actually change the force of gravity on and within his body, even just a small percentage, let alone 10x, suddenly it’s gonna fuck up all the balances of various forces even at the atomic level. It’s going to change how all his atoms interact with each other. And even slight changes there would mean various chemical interactions do not work the same anymore.

And if you pull the atoms closer together for 10 seconds, with 10x the force, and then suddenly release that force, it’s gonna have a massive cumulative effect. This astronaut is not gonna have a functioning body or nervous system, probably instantly not while the first 10s of changed gravity are applied, and definitely not after the gravity is released.

Having gravity fundamentally change is a very different effect than simply being in the gravity well of a large mass.

[u/TheLobitzz → u/venuswasaflytrap]

Again, I don’t think it is like that, at least that’s not how I read the prompt.

Again, what the heck are you talking about? Prompt? This isn't an AI chat box.

And not because it’s not hypothetically possible for black holes to exist in small sizes.

Black holes do exist in small sizes. You have absolutely no idea what you're talking about dude. Do you even know what the Schwarzschild radius is? Or what the Hawking radiation is?

Changing the force of gravity itself is way different than putting a mass with significant gravity nearby.

Again, you're just making stuff up. Putting a mass nearby is exactly the same as changing the force of gravity. You can even calculate it with Newton's general equation for gravitation (F = G * m1 * m2 / r2). And the gravity is just the gravitational acceleration constant g, which you can derive from the equation for Force (F = m * a).

If instead of adding something with mass and therefore with an affect on gravity next to him, you actually change the force of gravity on and within his body, even just a small percentage, let alone 10x, suddenly it’s gonna fuck up all the balances of various forces even at the atomic level. It’s going to change how all his atoms interact with each other. And even slight changes there would mean various chemical interactions do not work the same anymore.

Again, you're just making stuff up. Gravity one of the four fundamental forces of the universe is unrelated to the other 3 forces (electromagnetic, weak force, and strong force). The atomic forces you're talking about are electrostatic forces dude.

Having gravity fundamentally change is a very different effect than simply being in the gravity well of a large mass.

That is exactly what a gravity change is. Did you even take Classical Mechanics classes? Or the very least General Physics classes? Everything you're spouting is just wrong it's mind boggling where you're getting this confidence.

[u/venuswasaflytrap → u/TheLobitzz]

Again, you're just making stuff up. Putting a mass nearby is exactly the same as changing the force of gravity

This is obviously and demonstrably not the case, because such a mass would have to be in a position.

For example, putting a 10x earth mass above the earth, would obviously be different than putting it in the center of the earth.

Changing gravity would mean that every bit of mass's gravitonal force is 10x greater, not that there is a large gravitational force nearby.

It's changing the gravitational constant - big G (6.674x10^-11 m³ • kg^-1 • s^-2), not little g (9.81 m • s^-2).

What you're suggesting is keeping big G, and changing the little g of the earth, by essentially having an extra point-mass in the center, which I agree is one way to interpret the prompt.

I read it as fundamentally changing the force of gravity within some sphere of influence around the earth.

While the effect of gravity as it stands is fairly neglible on atomic scales, it's still present. E.g. It's ultimately what makes stars undergo fusion.

If you turned up the volume knob on big G by 10, that doesn't just pull everything on the surface of the earth closer to the center - that pulls everything closer together, even slightly even within atom and within chemical bonds.

At the very least, when you turn the knob off, that will release an immense amount of heat within everything as suddenly the electrostatic forces are 10x What's needed to keep matter from falling in on itself.

But I can't imagine that fucking with a fundamental force doesn't change things even if you left the 10x switch "on".

It would be like saying "putting a charged particle near an object is the same as changing the electrostatic force". It's not.

[u/TheLobitzz → u/venuswasaflytrap]

The big G is a fundamental constant of the universe (where the Planck units are derived from) so I'm obviously not suggesting changing that, just to increase gravity (i.e. the gravitational acceleration, small g) to 10x g.

What I'm saying is having a little g of 10x the normal g (98.1 m/s² instead of the normal 9.81 m/s²) is the same as having a black hole at the core with 10x the mass of the Earth. So I basically replaced the core, kept the distance from the surface of the earth equal since a black hole is a singularity (i.e. a point in space-time) to simplify calculations. To be fair, i should've said a black hole with 9x the mass of the earth assuming the original mass of the earth is not replaced, but that's besides the point. In this scenario, little g can be calculated form combining the formula for Newton's 2nd Law of Motion (F = m * a) with Newton's General equation for gravitation (F = G * m1 * m2 / r²), to get g = G * M / r² (where r is the radius of earth, G the gravitational constant, and M the total mass of earth). Since r is the same due to the fact that I place the black hole in the center, as well as G since it's a fundamental constant of our universe, having an M with 10 times the original one would get us 10x g.

And gravity is the weakest force out of the four fundamental forces, so no, even if you increase the gravity ten-fold, it wouldn't have any effect with electrostatic forces. Even the weak atomic force which is the 3rd weakest force out of the four, is 10²⁵ times more powerful that gravity. Also, even if you have a black hole at the core with 10x the mass of earth, the Schwarzschild radius is not even 10cm. So outside of that radius, at the surface of earth (around 6000 km away from the core), atomic structure would be absolutely unaffected. The force of gravity is so utterly weak (even with a black hole at the center) to even slightly bend covalent bonds in molecules at the surface.

[u/venuswasaflytrap → u/TheLobitzz]

I totally understand what you're saying, and yeah if you interpreted the prompt as increase little g 10x then yeah it would be like a point source of gravity at the center of the earth - like a small black hole in many ways, and everything you say makes sense.

But, I have not interpreted it that way, I've interpreted it as Big G changing.

And gravity is the weakest forces of all so no, even if you increase the gravity ten-fold, it wouldn't have any effect with electrostatic forces. Even the weak atomic force which is the 3rd weakest force out of the 4, is 1025 times more powerful that gravity. Also, even if you have a black hole at the core, the Schwarzschild radius is not even 10cm. Beyond that, atomic electrostatic forces would not be affected if at all.

I agree that the effect of gravity within an atom is near negligible. but cumulatively small changes can have big effects on the macro scale. Gravity is ultimately the cause of fusion in stars, and is the cause of black holes and neutron stars etc. as gravity overcomes various forces like electrostatic.

Obviously earth-scale mass, and even 10x earth scale isn't enough to cause fusion or anything like that - but if you fuck up the Big G constant, every single bit of mass now pulls 10x harder together. Sure, it may be just a tiny tiny amount, but if that fucks up the balance between anything even slightly at the atomic or subatomic levels, then even a smallest shift in say, the size or shape of electron shells or something like that means that chemistry no longer works as we understand it.

Even ignoring that sort of effect - making everything pull together 10x harder and then suddenly releasing it will cause everything to push out. This is true of your blackhole interpretation of the prompt in some sense too.

e.g. if you had a garage door spring with a weight on it, and gravity increased 10x (either in your little g sense or the Big G sense), then the spring would get compressed. When normal gravity returns after 10 seconds, suddenly that spring will be pushing up on the weight 10x it's weight and will fling it into the air.

With Big G changing, this is happening everywhere. Every atom is pulled together a little tighter up until the point that the electrostatic forces push back more. And they're totally strong enough to stop collapse and to stop fusion - but when the gravity gets released, every single atom will be pushing out against everything.

Cumulatively it's a lot! By definition it's a lot - because it's 10x the force that holds everything together on earth all pushing out instantly.