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  • radiation cooling question

    From Peter Fairbrother@peter@tsto.co.uk to sci.physics on Mon Nov 3 23:16:23 2025
    From Newsgroup: sci.physics

    Suppose a volume made from a perfect reflector filled with radiation. A
    door opens into a larger volume, also made from a perfect reflector.

    Does the photon energy decrease?

    How?

    Thanks,

    Peter Fairbrother
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  • From Jambo Tambo@not@here.now to sci.physics on Mon Nov 3 21:31:52 2025
    From Newsgroup: sci.physics

    Peter Fairbrother <peter@tsto.co.uk> wrote:

    Suppose a volume made from a perfect reflector filled with radiation. A
    door opens into a larger volume, also made from a perfect reflector.

    Does the photon energy decrease?

    How?

    From a classical standpoint, no. I suspect, however, that the entropy
    will increase when you open the door, but I can't justify that.

    From a quantum standpoint, there may be other factors, so I don't know.


    Thanks,

    Peter Fairbrother

    Thanks for that interesting but completely idle question. HTH, YMMV.
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  • From ram@ram@zedat.fu-berlin.de (Stefan Ram) to sci.physics on Tue Nov 4 09:04:14 2025
    From Newsgroup: sci.physics

    Peter Fairbrother <peter@tsto.co.uk> wrote or quoted:
    Suppose a volume made from a perfect reflector filled with radiation. A
    door opens into a larger volume, also made from a perfect reflector.
    Does the photon energy decrease?

    No.

    How?

    Because there's nothing else around here that could take on any
    energy the photons might lose.


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