What would happen if you crushed a car to the size of a baseball?

March 1, 2012 9:14 AM

Superhero Physics: If you telekinetically/magically crushed an automobile to the size of a baseball, what would happen exactly?

Let's say you're Telekinesis-Man, and as a demonstration of your power, you're going to crush a car down to a perfect sphere the size of a baseball. Everything in the car will be crushed -- steel, aluminum, plastic, rubber, gasoline, oil, etc. The crush process would happen in exactly one second, from start to finish.

What would happen exactly? What material changes would you expect to see? What would you end up with? Would it hold together or crumble? Would it be hot?

Also, let's say that before, during and after, the car will be continuously exposed to air.

For discussion's sake, a baseball is 3 inches (76 mm) in diameter. And let's say we're talking about a typical four-door sedan with a gasoline engine, with a curb weight of 3,000 pounds (about 1360 kilograms).

posted by Cool Papa Bell to Grab Bag (14 answers total)

I'm pretty sure you would create the densest matter known to man by an order of magnitude or so, and then it would likely blow the hell up or something once you removed your telekinetic crushing force from around it. But I'm sure some real physicists will chime in with a more mathematically sound answer shortly.
posted by Grither at 9:34 AM on March 1, 2012 [1 favorite]

Wolfram link. According to that, you'd create matter 40 times more dense than the matter at the core of the sun, so, pretty dense, but it's still orders of magnitude less dense than a neutron star.

I think you'd just have a ball of really dense matter. The thing is, it wouldn't want to stay that dense under atmospheric pressure, so unless your hero kept the pressure on it it would explode outward as soon as she stopped with the telekinesis.
posted by Aizkolari at 9:38 AM on March 1, 2012 [5 favorites]

That would be about 5.9 x 10^6 kg/m^3, or about 40 times the density of the core of the sun, but not as dense as a white dwarf. Depending on how rapidly this occurred and the exact makeup of the car's frame, the result would probably be a massive fusion reaction.
posted by jedicus at 9:41 AM on March 1, 2012

My gut reaction would be "Earth-shattering kaboom", or something like that. You're talking about compressing a solid object to a density much higher than it would normally have at atmospheric pressure. Most solids are slightly compressible, but not significantly so; the pressures required to compress a metric ton of steel down to a volume of less than a liter would be incredibly high. You could in principle calculate this using the bulk modulus of steel; my back-of-the-envelope estimates would be somewhere in the 10^11-12 Pascal range, or approximately ten million atmospheres.

As you compress the steel, it will heat up. The gasoline will probably spontaneously ignite due to the high pressure and temperatures, so that will make a nice fireball. The steel will probably melt as well. I don't know if you'd be providing enough pressure and temperature to start nuclear fusion reactions, but I wouldn't be surprised if there were a few. (Iron can't release energy by fusing, but the aluminum, carbon, and hydrogen in the car's materials could.) And, as pointed out by Grither, once you removed your magical telekinetic force, the material wouldn't be subjected to this enormous pressure any more, and would expand back out — probably rather violently.

Net result: hot, possibly radioactive metal slag scattered about the countryside. Telekinesis-Man had better have long-range superpower or invulnerability.
posted by Johnny Assay at 9:43 AM on March 1, 2012 [11 favorites]

I'm pretty sure you would create the densest matter known to man by an order of magnitude or so,


A Baseball is about 12.31 cubic inches, a car is about 4000 pounds, giving you a density of 9 million kg per cubic meter, which is quite a few orders of magnitude less dense than a neutron star, but I think that's well above the density where fusion would happen..
posted by empath at 9:43 AM on March 1, 2012 [1 favorite]

The question is what forms of fusion? Before you get to that stage you'll probably have something like an pyroclastic magama with volatiles dissolved in a solution of molten iron. With the bulk of the mass as iron, most fusion reactions would be endothermic.

Either way, you're going to have a degenerate plasma on your hands (tightly-packed nuclei with free-floating high-energy electrons) which will explode once the pressure is released.
posted by CBrachyrhynchos at 9:55 AM on March 1, 2012

Well, I'm not a physicist. But if I were to do some estimates on the size/weight...

According to thisthis, 1 cubic foot of steel weighs about 490 lbs.

If you assume that the car's 3000 lbs are all from materials that are as dense as steel on average, then the volume of a car's materials compressed to a sphere or cube with no cavities would result in a sphere of 3000 / 490 = 6.122 cubic feet of material = 10,579 cubic inches.

A 3 inch sphere (baseball) has a volume of 4/3 * PI * (3 inches^3) = approximately 113 cubic inches. So if you compressed the 6.122 cubic feet of material to that size, you'd be compressing it to 113 / 10,579 = just over 1% of its natural size in earth's atmosphere.

I'm not sure how much force would be needed to compress solid steel to 1% of its natural size in 1 second, but I'm sure it would be extreme. I'm also sure it would get very very hot and would, as others have said, create an enormous explosion if the pressure were suddenly released.

If the telekinetic individual wanted to compress the car into a sphere that didn't require extreme compression of the material itself, he could compress it into a sphere that occupies 6.122 cubic feet, which would be about 27.24 inches in diameter, or roughly the size of a medium-size exercise ball.
posted by Vorteks at 9:59 AM on March 1, 2012

Correction to my previous answer - I was using 3 inches as the radius instead of the diameter. The radius would be 1.5 inches. So a baseball would actually be about 14.137 cubic inches, making it about 0.13% of the natural size of 3000 lbs of steel in atmospheric pressure.
posted by Vorteks at 10:09 AM on March 1, 2012

Of course, by "known to man" I meant "on the planet". Slip of the old typing implement, obviously.
posted by Grither at 10:59 AM on March 1, 2012

I believe this is what is roughly happening :

1. As you start compressing the matter, fusion will start happening (as someone mentioned above - lighter material than iron) that will start to oppose your telekinetic powers. Pretty much a mini sun. As it gets compressed more, the fusion energy gets released in a very short amount of time - a mini super nova with gigantic bursts of radiation. If for some reason your power can contain matters, only radiation escapes.
2. Depending on how fast the compression takes but there will be first Hydrogen fusion, then helium, and so on and so forth. So there will be many bursts happening.
3. At the end of the fusion reaction, this will pretty much be a white dwarf.
4. Then the chandrashekar limit will be reached where the opposing force of the collapse is not fusion anymore but electron degeneracy pressure. Same thing would happen with bursts of radiation as your power overcomes it. (Although this would probably mean the object is smaller than a baseball)
5. At the end of this, you'll have a neutron star.
6. As you continue compressing it, neutron degeneracy pressure is overcome. It collapses even more while releasing yet another radiation bursts.
7. You now have a blackhole.
8. ???
posted by 7life at 10:59 AM on March 1, 2012 [1 favorite]

I'm not that convinced of very much fusion given the relative abundance of iron in the mix. I suspect you'd see more nuclear transmutation reactions, which don't necessarily require high energies.
posted by CBrachyrhynchos at 11:29 AM on March 1, 2012

Iron can fuse, it's just that you get less energy from the fusion than you have to put in to get it to happen so the reaction isn't self-sustaining. Telekinesis-Man will just have to keep putting more energy in to make up for all of the compressive force that's being converted to heat and radiation, but this will be the case for lighter element fusion as well.

(although I have no idea whether baseball-size would actually be small enough for this to happen.)
posted by A Thousand Baited Hooks at 12:19 PM on March 1, 2012

Yeah, the iron fusing would definitely still release radiation. Assuming that radiation can escape the forcefield that Telekenisis-Man is using to crush the car, you would get a shitload of heat, light, UV, and probably plenty of harder stuff too out of the car as it was compressed. How much I am not sure... a nuclear physicist could probably figure that out but I'm just a lowly biologist here.
posted by Scientist at 2:27 PM on March 1, 2012

So apparently, not actually dense enough to fuse iron -- Not dense enough to fuse carbon, even.

So it would just be an extremely hot plasma...
posted by empath at 4:31 PM on March 1, 2012