# Proton Temperature **URL:** \ **Category:** Factual Questions\ **Created:** [July 30, 2000, 4:14am UTC](https://boards.straightdope.com/t/proton-temperature/27401 "2000-07-30T04:14:43Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [July 30, 2000, 4:14am UTC](https://boards.straightdope.com/t/proton-temperature/27401/1 "2000-07-30T04:14:43Z")
I read recently an article that talked about certain protons “having a temperature of 10[sup]13[/sup] degrees”. How does one interpret the temperature of a proton? As its kinetic energy? ---
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [July 30, 2000, 4:49am UTC](https://boards.straightdope.com/t/proton-temperature/27401/2 "2000-07-30T04:49:35Z")
I’ve never heard of temperature of a proton before, so I’m guessing, but here goes. The temperature of an ordinary substance is the average kinetic energy of a molecule. So, maybe the temperature of a proton is the average kinetic energy of the quarks (and gluons?) that make up the proton. I have no idea how you would go about taking a photon’s temperature, though. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [July 30, 2000, 4:52am UTC](https://boards.straightdope.com/t/proton-temperature/27401/3 "2000-07-30T04:52:35Z")
I haven’t heard of it before either. My guess is that it simply has a kinetic energy that corresponds to that temperature. You really can’t define a temperature of a single particle, but if you have a collection of particles (gas or plasma), the average kinetic energy of all particles is proportional to temperature. So you can sort of associate a given kinetic energy with temperature. ---
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [July 30, 2000, 5:24am UTC](https://boards.straightdope.com/t/proton-temperature/27401/4 "2000-07-30T05:24:19Z")
**scr4** said, “So you can sort of associate a given kinetic energy with temperature.” Yeah, but 10[sup]13[/sup] degrees sounds kinda energetic. Then again **KarlGauss** said “certain protons”. If you have a sample of hydrogen gas which is essentially protons; the temperature is the _average_kinetic energy. The kinetic energy is randomly distributed. So, I suppose _some_of the protons would have to have kinetic energy corresponding to a temperature of 10[sup]13[/sup] degrees or even higher. I’m still just guessing here. Do you have any more information so we can get a better idea of the context? I always thought that temperature of an individual particle was not defined. Temperature only makes sense (to me at least) when speaking of a collection of particles. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [July 30, 2000, 5:41am UTC](https://boards.straightdope.com/t/proton-temperature/27401/5 "2000-07-30T05:41:31Z")
> [@](#): > > I always thought that temperature of an individual particle was not defined. Temperature only makes sense (to me at least) when speaking of a collection of particles. Yeah, I agree. But the average kinetic energy in a system is kT, right? (k=Boltzmann constant=8.6_10[sup]-5[/sup] eV). So maybe “10[sup]13[/sup] degrees” is their way of saying "8.6_10[sup]8[/sup] eV proton." That’s 860 GeV - awfully fast, but not exceptional for cosmic rays, for instance. ---
**Author:** ![douglips](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@douglips](https://boards.straightdope.com/u/douglips)\ **Post date:** [July 30, 2000, 6:09am UTC](https://boards.straightdope.com/t/proton-temperature/27401/6 "2000-07-30T06:09:02Z")
Could this be the quark plasma/soup thing recently discussed? At CERN, I think it was, they recently got up to enough energy to make a quark plasma. That plasma could be said to have a temperature. I can’t find the articles in a quick search, so I’ll just have to WAG that the temperature would be 10[sup]13[/sup] K, give or take a few orders of magnitude. (How’s that for a hedge?) ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [July 30, 2000, 5:03pm UTC](https://boards.straightdope.com/t/proton-temperature/27401/7 "2000-07-30T17:03:23Z")
Thanks for your comments. The context was in an article that I was reading about the event horizon at a black hole. They were talking about the tremendous energy of the infalling mass and said, specifically, that _ **a** _ proton at the horizon has a temperature of 10[sup]13[/sup] degrees. They went on to say that the proton is not efficient at giving off such a high energy but, instead, transfers it to electrons which are quite effective emitters (or words to that effect). ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [July 30, 2000, 5:05pm UTC](https://boards.straightdope.com/t/proton-temperature/27401/8 "2000-07-30T17:05:18Z")
Sorry. That should read “infalling **matter** ” not mass. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [July 30, 2000, 5:49pm UTC](https://boards.straightdope.com/t/proton-temperature/27401/9 "2000-07-30T17:49:38Z")
> [@](#): > > said, specifically, that a proton at the horizon has a temperature of 10^13 degrees. This sounds like just poor phrasing. Any blackhole which is radiating energy due to infalling matter is going to have more than just a single proton falling in. When reading about science, it’s often a challenge to figure out what’s going on after it goes through the filter of the writer. Like lookign at a person through frosted glass, you know that the person on the other side doesn’t really look like what you’re seeing.