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Confused about e=mc2

  1. Aug 4, 2010 #1
    I'm not really a physics genius or professor so forgive my lack of knowledge.
    I was thinking about Einstein's theory of relativity earlier,then it just popped into my head doesn't that contradict The Law of Conservation of Charge?Ex:111grams of hydrogen = 10,000,000,000,000,000 Joules.but in order to achieve that amount it will have to be completely destroyed.

    I thought matter and energy cannot be destroyed.Is it just converted and what i had read was misleading and inaccurate.
  2. jcsd
  3. Aug 4, 2010 #2


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    Staff Emeritus
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    Mass and energy are not separately conserved in relativity. What is conserved is mass-energy, which is found by adding up all the mass and all the energy (after using [itex]E=mc^2[/itex] to convert them both into the same units). Conservation of charge is a separate issue. Charge is conserved. For example, when an electron and an antielectron annihilate one other, the total initial charge is zero, and the total final charge is also zero.
  4. Aug 4, 2010 #3


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    Staff: Mentor

    Yes the first time you are exposed to conservation law in school it is typically simplified.
  5. Aug 4, 2010 #4
    I wondered how Wikipedia explained mass and energy and found this:

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