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Energy into matter questions

  1. Jun 17, 2013 #1
    From my understanding it's impossible for electrons to directly turn themselves into neutrons and protons. Electrons are an elementary particle while neutrons and protons are made from elementary particles (quarks).

    1# So 'energy into matter' replicator like star trek are impossible using only electricity (electrons) right? For this to work you would need a 'reservoir' of protons, neutrons and electron?

    2# Do solar panels create electrons or do they simply cause the ones that exist to move around? Seems if they create a hole/electron pair, then a massless photon created a massive particle?
  2. jcsd
  3. Jun 17, 2013 #2
    You can't convert electrons alone directly into energy. One way to understand this is conservation of certain kinds of particle number. For example, lepton number is typically conserved, and the electron has lepton number 1, while a photon ("pure energy") has lepton number 0. So the process electron-->photon doesn't conserve lepton number and is therefore impossible. Moreover, that process doesn't conserve charge. To get an electron to turn directly into energy, you could combine it with a positron, the electron's antiparticle. Particle-antiparticle fusion always conserves quantum numbers, and can yield just a photon (or multiple photons) as a result.

    Solar cells just propel the electrons around. The same is true of batteries and the electrical generators at power plants.
  4. Jun 17, 2013 #3

    Jano L.

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    Gold Member

    1: Yes, it's still a great sci-fi. We do not know how such replicator would work.
    2: The electrons are in the panel already, the radiation just makes them move systematically and form electric current.
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