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Matter <-> Energy converions

  1. Aug 9, 2004 #1
    Matter <--> Energy converions

    Is it accurate or inaccurate to think of matter <-->energy conversions to be a "Phase Transition" in the same way that ice to water to steam conversions are examples of phase transitions? And Why?

    Thanks,
    Glenn
     
  2. jcsd
  3. Aug 11, 2004 #2
    it is accurate. Matter is energy and energy is mass. [tex] E = mc^2 [/tex]
     
  4. Aug 11, 2004 #3

    DW

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    You missed a coefficient.
    [tex]E = \gamma mc^{2}[/tex]
     
  5. Aug 12, 2004 #4
    First off it is mass-energy conversion and not matter-energy convertsion. The former has a precise meaning while the later is foggy since "matter" has never been something that one can reasonably quantity unless you replace it with the term "mass".

    Second off - It is inaccurate to think of matter-energy conversion as a phase transition. You're talking about two seperate things in mass-energy conversion wherein phase transitions you're talking about the same thing in different states. Mass should never be thought of as frozen energy.

    Why? The very meaning of E = mc2 is that an increase in energy can result in an increase in mass and vice versa. There is no reason to think of that as a phase transition. For example: Suppose you blew air into a rubber balloon. Then the balloon would blow up and the surface area o the balloon would increase. Therefore, increase air - increase surface area. Or you can simply say, increase volume - increase surface area. But what you can't say is that the surface is a phase of volume or that volume and surface are two aspects of the same thing.

    Pete
     
    Last edited: Aug 12, 2004
  6. Aug 12, 2004 #5

    DW

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    No, it is missing the zero subscript on the energy, but means that mass is rest energy.
     
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