See subject. Note: I know there is no place without gravity (uh…right?), except my own private local field like the da Vinci Vitruvian Man, and that the cohesion of the atoms, etc, that makes my body exist wouldn’t be, and I that I don’t think I’d become a star, per se. Just interested in where I’d end up. (Also I wouldn’t be I, but I know.)
Prompted by current thread by Cerealbox and this response by Dr. Strangelove.
Moderator Note
Added the accidentally omitted word “no” to the title at the OP’s request.
Thanks mod whoever you are for fixing my hed, yet again.
ETA: ninja’ed by ECG. 
I just now notice that “unique” locality is discussed in the current thread Motion and Kinetic Energy: a question for science experts.
I’ll now add a third direct quote from a Doper, mandala, the OP of that thread, because he said it best:
“Relies to the effect of “this is the dumbest question ever” will gracefully accepted (and ignored). Thanks!”
Leo
I don’t know what you would end up as, but you wouldn’t become a star. A star only becomes a star because it has enough mass to squish itself together to the point where fusion stars. If you don’t have enough mass, you don’t get enough squish.
Small objects, like you, don’t even have enough mass to squish themselves together into a sphere. Asteroids, even fairly large ones, can be very oddly shaped. Once you get big enough (the size of a small planet) you get so much mass that your shape gets pulled into a sphere. There’s a limit to how tall mountains can be on the earth. If they get too tall, they just get pulled back into the sphere by gravity. Mars, with its lesser gravity, can have taller mountains. Olympus Mons is thought to be pretty close to the max height for a mountain on mars. Even with enough mass to squish itself into a sphere, none of the planets will become stars.
Once you get up to the size of Jupiter, then you’re at least in the right ballpark. But even Jupiter won’t collapse into a star. It doesn’t have enough mass. Ironically, if you were to somehow add mass to Jupiter, it would start to shrink in size. This is because the extra gravity would start to pull everything inward. Its core would get hotter and more dense. Then, as you add more and more mass, the core would eventually get so hot and dense that it would start to support fusion. And then you basically have a star.
You’re a long way away from that.
Ya-huh, it will! I saw a movie that proved it. We’ll have to wait and see because the movie takes place in the future- it won’t actually happen until the year 2010 but it will happen!
My God—it’s full of stars!
As engineer_comp_geek pointed out, you just don’t have enough mass to become a star, or even a sphere.
Your body is more or less held in shape by electromagnetic forces (there are some quantum mechanical forces as well, but we can ignore those for now). The important point is that gravitational forces are unbelievably weaker than electromagnetic. Like a billion, billion, billion, billion times weaker. That’s why a thin layer of atoms on the bottom of your shoe can resist your weight against the pull of the entire earth. There’s just no way the gravity of your body can ever outpull the forces between your atoms.
But the thing about gravity is that it’s always additive. Electromagnetic forces are balanced by positive and negative charges, and if one place gets too positively charged (and thus exerts too strong a force), some negative charges will move in and ruin the party. Gravity, though, keeps adding and adding without limit. Gas condenses into stars, which shrink into neutron stars, which collapse into black holes.
If you were floating in a big cloud of gas, you could conceivably act as the center for a new star. Your gravity, weak as it is, will cause a slight attraction to nearby gas, which itself will be that much more attractive to more gas. Practically speaking, any cloud of gas will already have density variations that outweigh the mass of a human, but it’s not outright impossible for you to be the center.
Unless Leo is a whole lot fatter than we ever thought . . . :eek:
On the internet, no one knows you’re a protostar.
Leo’s getting laaaarger!
I think the OP intended to stipulate that those are switched off. However, even then, there’s the quantum mechanical stuff you mentioned to consider, namely electron degeneracy pressure: the Pauli exclusion principle prohibits two fermions (spin-1/2 particles) to be in the same quantum state, and thus, occupy the same region in space. This manifests as a pressure against the gravitational compactification; large stars are able to overcome this pressure, becoming neutron stars, where the neutron degeneracy halts further compactification, or black holes, if even that can be overcome.
If there were no other forces than your own gravity, with the aid of a few gross simplifcations, I make it that it would take about 30 mins before you collapse into some very dense object.
That was by approximating Leo as a sphere (sorry, but you shouldn’t have had so much to eat this Xmas) of average American weight and the density of water (which is the average density of the Human body, so I believe).
Just out of curiosity, if the gaseous material which makes up Jupiter were transformed into solid material capable of supporting a solid object , then …assuming the mass of Jupiter were to remain the same as it is now …what would happen to a human being who landed on the surface ( this intrepid venturer has a back pack with very powerful retro rockets so he can in fact make a soft landing).
When he switches off the retro rockets, will the gravity of Jupiter reduce him instantly to a shapeless blob on the surface ? Or would that require a much larger gravitational pull ?
The gravitational force at the ‘surface’ of Jupiter is about 2.5 times what it is on the surface of Earth, which I think would be uncomfortable, but possibly survivable in the short term for a human(?).
Looks to be not too difficult. Just don’t fall down or hang from your feet…
Interestingly, and what I only just noticed, in my equation for the collapse time of a spherical Leo Bloom, the time to collapse is a function of his average density only and not of his mass or his radius.
Thanks; obviously I didn’t read the OP carefully enough. It’s a bit of a difficult question since it’s one of those “contrary to reality” type that have different answers depending on exactly which constraints you relax.
AF’s answer sounds good, and I suspect makes the assumption of the matter turning to “dust”–infinitely small particles that exert no pressure when compacted. This isn’t a bad model and is one of the ways that physicists model the universe as a whole (where galaxies act as the particles).
That said, an equally valid answer is that you’d fly apart at a high speed and never coalesce. If your body starts at normal body temperature, then the particles on average have a fairly high velocity. Normally this isn’t a problem since other forces keep the particles together. But if you were to shut down all these other forces, then any particle with higher than escape velocity is going to fly off, never to be seen again. And that’s almost all of them, since the escape velocity of a human-scale mass is very tiny.
The Pauli Exclusion Principle can’t itself actually generate a force. It’s true that two fermions can’t occupy the same state simultaneously, but how close two can be before it’s the same state depends on the forces between them. Hence, ultimately, degeneracy pressure is a manifestation of one of the familiar fundamental forces: In a white dwarf, it’s the electromagnetic force, and in a neutron star, it’s the strong nuclear force.
Similarly, the surface orbital period around a spherical object also depends only on its density (it’s about four times as long, depending on precisely how you did your calculation).