Re: The temperature of a photon ?
- From: "Peter Christensen" <PeCh@xxxxxxxxxxx>
- Date: Tue, 5 Sep 2006 11:59:38 +0200
"Sam Wormley" <swormley1@xxxxxxxxx> skrev i en meddelelse
news:dAbLg.126441$FQ1.69668@xxxxxxxxxxxx
Peter Christensen wrote:
Does it make sence to talk about the temperature of a photon? (-My own
answer is no.)
It always applies that E = p*c (p is the momentum which depend only on
the wavelength) for a photon. But as the speed of light is always c,
there can't be a kinectic energy as for massive particles, where E_kin =
1/2 m*v^2 can be expressed as a measure of temperature for a particle.
I know, that a radiation profile (photons) can express the temperature of
it's source, but I still don't think, that it will make sence to talk
about a temperature for single photons, as it would do when talking about
massive particles with E = E_kin = k_B*T.
Are there anybody who would like to try to define a temperature for a
photon?
PC
When a cosmologist talks about the 'temperature' of a photon they are
basically describing the equivalent energy of a photon.
http://www.physlink.com/education/askexperts/ae210.cfm
From the link: "So when a cosmologist talks about the 'temperature' of aphoton they are basically describing the equivalent energy of a photon."
This means E = h*f = k_B*T. But as in this reference, I would also use the
word 'temperature' in ''. But it's a measure of the temperature of it's
source, no doubt about this.
Planck's Law
http://scienceworld.wolfram.com/physics/PlanckLaw.html
A good link...
PC
.
- References:
- The temperature of a photon ?
- From: Peter Christensen
- Re: The temperature of a photon ?
- From: Sam Wormley
- The temperature of a photon ?
- Prev by Date: Re: The temperature of a photon ?
- Next by Date: Re: The temperature of a photon ?
- Previous by thread: Re: The temperature of a photon ?
- Next by thread: Negative Kelvins
- Index(es):
Relevant Pages
|
