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Is There Such a Thing As Absolute Hot?
AlpineR writes "Is there an opposite to absolute zero? An article from PBS's NOVA online explains several theories of the maximum possible temperature. Maybe it's the Planck temperature, 10^32 K, beyond which the known laws of physics break down. Or maybe just 10^30 K, the limit of some versions of string theory. If space is actually 11-dimensional then the maximum temperature could even be as low as 10^17 K, attainable by the Large Hadron Collider. Or maybe infinite temperature wraps around to negative temperature and absolute hot is the same as absolute cold."
That's what you get for writing a universe in C.
I am trolling
I would have never thought there was a speed limit for the universe before I read Einstein's special theory of relativity. Anything is possible.
"Maybe this world is another planet's hell"
Aldous Huxley
> "Or maybe infinite temperature wraps around to negative temperature and absolute hot is the same as absolute cold."
Or maybe the universe is a snake eating its own tail!
Or maybe monkeys will fly out of my butt.
Yes, and it's my wife's sister. I love the holidays!
McDonald's coffee?
Margaret Thatcher. Covered in whipped cream. (apologies to anyone who was planning to close their eyes in the near future)
If you haven't made a developer cry, you've wasted a day.
DUH!
While it may well be that there is a maximum "energy density" for a particular space, it would not really be a true opposite to absolute zero. Absolute zero represents complete cessation of motion... a true opposite would be infinite motion (obviously not infinite velocity). Also, it seems quite possible that whatever upper limit exists at one particular time in one particular space may differ from another... either varying as the universe ages, with whatever gravitational field may exist locally, or at the very least in different universes that may exist. As such, while absolute zero is just that... absolute (in that no heat is no heat under all conceivable reference points), "absolute heat" almost certainly does not uniformly exist. I suppose another way to say is that if you plug absolute zero in as the value in a mathematical calculation, you will always get the same result, but there is no one value "absolute heat" corresponding, which can closely approach actually existing in our universe.
"Is there such a thing as absolute hot?"
1. Turn on a burner on the stove. Turn it up as high as it will go.
2. Wait 5 minutes for the burner to warm up.
3. Place the palm of your hand on the burner.
4. You tell me.
Seems to me there would have to be an absolute hot. Absolute zero, ferinstance, is the temperature at which all molecular motion stops. Nothing moves at absolute zero. Heat would, then, be a function of how fast the molecules are moving in a given substance, right?
Given that the universe has an effective speed limit ( C: it's not just a good idea, it's the law), it seems to me that for a given substance, there has to be an upper limit of how hot it can get solely because the molecules within it aren't allowed to vibrate any faster. (I'm not certain that the function of vibration speed to heat isn't substance dependent-- it may be.)
However, given that the idea of an absolute hot is apparently not agreed upon by physicists, I am probably missing something important in my layman's analysis of the situation.
-F
Nope.
Temperature depends on particles _energy_. At low temperature particle energy is calculated as E=m*v^2/2, but if you start to get closer to the light speed then the _MASS_ of a particle will grow. So you can get arbitrarily large energy as you approach the "c" limit.
we should switch the scale of hotness: accept Carmen Electra as 1 unit of hotness as measured in the year 2000. Also accept that 2 Carmen Electras is twice as hot as 1 Carmen Electra. As the number of Carmen Electras approaches infinity, their total combined hotness approaches some saturation limit, after which it is no longer possible to determine whether hotness of N x Carmen Electra is greater than hotness of (N+1) x Carmen Electra, which breaks down the laws of mathematics and thus the laws of physics by making N=N+1.
I must add that Chuck Norris can kick Carmen Electra's ass even at the hotness limit.
You can't handle the truth.
Temperature is defined in terms of the energy, not speed. At high velocities the mass of particles grow with their speed as per Einstein's theory, so even thou the top speed is limited, energy is in fact not. As a particle's speed aproaches the speed of light its energy diverges. This is in fact WHY you can't accelerate particles to the speed of light. As you get closer to C the particle mass starts growing rapidly so larger and larger amounts of energy is needed for smaller and smaller increments in speed. Thus you can't accelerate a particle to C using only a finite amount of energy. This effectively means that realitivity doesn't limit temperature. There may of course be other limits involved.
Temperature is basically the average kinetic energy of the particles, and kinetic energy is half the mass times velocity squared, when things start to get very hot, the particles would eventually start getting up to relativistic speeds.
This has lead some people to suggest that the cosmic speed limit (the speed of light) imposes a cosmic temperature limit - but that's NOT the case.
As things start to move closer and closer to the speed of light, relativity says that their mass increases (as seen from the perspective of an outside observer). Whilst there is a cosmic speed limit - as you approach it, your mass increases without limit. Since unlimited mass and finite velocity means unlimited kinetic energy, relativity does not impose a cosmic temperature limit.
If there is a cosmic temperature limit, it's caused by something else.
www.sjbaker.org
>All this, of course, is purely theoretical and can never be accomplished because it's hard to accelerate any particle infinitely. But according to relativistic physics, an infinite temperature can exist.
No, relativity requires the application of infinite energy to reach the infinite temperature, just like classic mechanics. For this very reason it's impossible to reach it - you don't have the source of infinite energy in our Universe (probably).
However, quantum mechanics has _another_ theoretical limit. I don't really know its precise reason, but this 'handwaving' argument holds: imagine that you have a particle with VERY large speed. The mass of this particle can be large enough to create a black hole. And it will immediately start to lose mass due to Hawking radiation, which will be directed along the path of the black hole (due to relativistic focusing) in the opposite direction (it'll look like black hole with retrorockets).
So it's not possible to reach the infinite speed because our Universe seems to have the _maximum_ allowed finite speed.
But no one has tied relativity to quantum mechanics yet. Therefore those speed limits only apply to a narrow vision of the universe.
Sorry but Special Relativity and Quantum Mechanics are very well integrated: it was first done by Dirac in ~1932 and led to the prediction of anti-matter which was discovered a few years later with the positron (anti-electron). The Dirac (along with the Klein-Gordon and Proca) equations form the underpinnings of Quantum Field Theory which is what we use in particle physics to describe all the fundamental particles of nature (that we know of) and how they interact (except via gravity). This has Lorentz invariance built into it and is a complete union of QM and SR.
What is harder is to unify QM and GR. This has not been successfully done yet. You can create a quantized gravitational field relatively easily but the problem is that you have to specify a maximum energy scale in order to normalize it (in 3+1D at least). This is bad because there is no justification for a maximum energy scale once you include gravity where the physics will change. Hence either the theory is wrong or there is something else at some really high energy. In either case you cannot use it to make meaningful predictions and so we say we have no valid way, yet, to unify QM nd GR.
Temperature is directly related to the velocity of the atoms in a gas or plasma.
No - it is directly related to the kinetic energy of the atoms in a gas and the electrons and ions/nuclei in a plasma (there are no atoms in a plasma). In classical physics this is 0.5mv^2 but this is just the low energy approximation of the true KE which is "ymc^2-mc^2" where y=gamma=1/sqrt(1-v^2/c^2). As you can see this has no upper bound.
Turns out Newton's laws *are* wrong. They just aren't wrong *enough* for it to make much of a difference to us when you're talking about for example, day-to-day human activities, most of which involve speeds much lower than the speed of light. For calculating speeds of airplanes and automobiles, Newton's laws are reasonable approximations -- but they are indeed wrong according to the world of relativity.