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Another issue with the Hawking equations

  1. Sep 7, 2014 #1
    I previously posted on the idea that the Hawking equations looked wrong: https://www.physicsforums.com/showthread.php?t=666962

    I returned to this topic recently, and noticed something.

    If you multiply power by time, you should get energy. Multiplying the Hawking power by the evaporation time, gives a peculiar answer....see attachment.

    ideas?
     

    Attached Files:

  2. jcsd
  3. Sep 7, 2014 #2

    Drakkith

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    Staff: Mentor

    You can't just multiply quantities together and expect a relevant answer. The power law is how much power the black holes emits, which changes depending on the mass. Since the mass changes over time, you can't simply multiply the power law times the evaporation time.
     
  4. Sep 9, 2014 #3

    Drakkith

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    Staff: Mentor

    Just FYI, the power law gives the total power output of the black hole of mass M at a single point in time. As soon as energy is radiated away, the black hole loses mass and the radiated power increases.
     
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