I guess I’m more saying, is there an extreme opposite of absolute zero?
My understanding of physics could be wrong here, but if I understand correctly, absolute zero is the point at which all particle motion ceases. As things get colder, particles slow down; conversely, as they get warmer, particles speed up.
If this is true, isn’t there a maximum speed these particles could reach – the speed of light? Ergo, if an object was heated to the point where its particles were all traveling at c, wouldn’t that be the maximum possible temperature?
I have been reliably informed in the other atom thread that while atomic/molecular motion ceases at absolute zero, subatomic particle motion doesn’t, ie. electrons keep moving with or without an outside energy source.
Yes, there’s a maximum temperature. And your description is close, atomicbadgerrace. But it’s not necessary to actually reach C. All you need to do is go close enough to C that each particle of your object (or cloud of hot plasma by this point) gains enough relativistic mass that it collapses into a black hole. Since the hole removes the hot massive rapid particle from the universe, it can’t get any hotter and still stay here.
The particles couldn’t move any faster, but they could gain mass. Temperature is a measure of the average kinetic energy of whatever you’re measuring. For anything with mass, as it approaches c the mass, and thus the kinetic energy, will increase. You of course couldn’t reach c because the mass would become infinite and the dimension in the direction of travel zero, but you could get arbitrarily close, until, as was just pointed out by Sunspace , it disappears into a black hole. If you had a bunch of stuff to get rid of it might be worth a try, but the power bill would be huge.
Just moving fast can’t turn a particle into a black hole, because you’d have to specify fast compared to what, and there’s no absolute frame you can compare to. Now, on the other hand, if you have things colliding together at sufficiently high relative speeds, that could form a black hole.
It should be noted, by the way, that like most of the Planck quantities, the Planck temperature mentioned by Cecil is not a precise value, but a back-of-the-envelope estimate. That is to say, we know that if you take Einstein’s, Newton’s, Boltzman’s, and Planck’s constants, and smoosh them all together in the right way, you can get a unit of temperature, and we’re certain that we can’t describe the physics of something in the vicinity of that temperature. If there is such a thing as a maximum temperature, it would not be at all surprising if it turned out to be in that vicinity. But it also wouldn’t be at all surprising if the maximum temperature turned out to be twice that, or pi times it, or 1/137 of it. We just don’t know.
There is a practical maximum at approximately six billion K/[sup]o[/sup]C, at which point nucleons cannot exist; only photons can. (This is an inference from popularizations of conditions at the Big Bang, so I may have something in error.) Since temperature implies the existence of matter to be at that temperature, I find it hard to see how anything could be described as hotter.
Are you using the American “billion=10[sup]9[/sup]” or the traditional U.K. “billion=10[sup]12[/sup]”?
Many nuclei will break apart at 6 billion K, but the nucleons would be just fine. Incidentally, baryon conservation means you’ll never get rid of them by heating alone, but you will at least start to change which baryons you have when you get to about 2 trillion K.
While I did mean the American usage, it was done from memory and may be totally in error. The popularization did indicate that the initial temperature of the monobloc was sufficiently high that matter – meaning subatomic particles; they were clear on that – could not exist, only photons. That said, I’ll back off on what was clearly in error from your statement and await a cosmologist to sort out what I should have remembered, rather than my obvious misunderstanding.
Eh, even if you manage to break up the nucleons themselves, you’ll still have a quark-gluon plasma. And quarks are still fermions, which is the usual criterion for calling something “matter” rather than “energy” (like photons, which are baryons). While it’s conceivable that quarks are themselves made up of some smaller particles, there’s no real evidence for that, and even if they are, at least some of those constituent particles would have to themselves be fermions: If there’s anything at all to our understanding of the fundamental laws of nature, it’s absolutely impossible to build a fermion entirely out of bosons.
Besides which, it’s perfectly well-defined to speak of the temperature of a photon gas. Photon gasses are actually even a lot simpler to understand than gasses made up of massive particles.
From your context I can tell you meant to say “boson” here, but for others: Photons are bosons (as opposed to fermions), but they are not baryons (which are made of quarks).
Let’s just say he might have approximated the facts. Actually, the sentence in question doesn’t really compute as English, but I presume it is supposed to say (bolding=my guess) –
In any case, it doesn’t really work like that. As Chronos said, you need a collision with something else. Further, it’s not the case that nature won’t let things get beyond the Planck temperature. It’s that we know our theories are badly broken above the Planck temperature – but that’s all we know.
