Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Energy <-> Mass conversion and visible light

  1. Jan 30, 2010 #1
    Energy <---> Mass conversion and visible light

    We are all familiar with the following concept:
    E = MC2

    and

    M = E / C2

    My question goes as follows, theoretically speaking, if at my disposal is adequate amount of energy to convert that energy into a mass of 6×1024 KG, what is the length in time that visible(to the human eye) light will be generating?
     
  2. jcsd
  3. Jan 30, 2010 #2

    Nabeshin

    User Avatar
    Science Advisor

    Re: Energy <---> Mass conversion and visible light

    This doesn't make any sense, even in grammatical structure, so I have no clue what you're talking about. I have 6e24*c^2 Joules of energy, okay, what do you want to know about it?
     
  4. Jan 31, 2010 #3
    Re: Energy <---> Mass conversion and visible light

    Hi Nabeshin,
    yes, I am grammatically challenged, but very curious and interested in nuclear physics, but my knowledge of it, in comparison to the maturity of a human, is like a baby crawling around in diapers :-) and I also very much appreciate your time in the attempt to answer the question.
    Lets see if I can restate the question:
    What would be the length of time that visible(to the human eye) light would be emitting from the process of converting appropriate amount of Joules energy into a body of mass of 6.0×(10 to the 24th power) KG ?
    In other words, since... Mass[6.0e+24 kg] = Energy[5.373e+41 Joules] / (300,000 [Km per sec] ^2), is there a way to calculate the duration of photon emissions in the visible spectrum frequencies while converting energy into a mass of 6.0e+24 Kg.
    I hope this makes a little more sense. I am sure that there are other dependencies in this process that I am, as of now, ignorant of :-).
     
  5. Jan 31, 2010 #4

    f95toli

    User Avatar
    Science Advisor
    Gold Member

    Re: Energy <---> Mass conversion and visible light

    You seem to be confusing power and energy. The time would depend on which process you used to convert the mass to energy.
    Your question is equivalent to asking: I have a battery with a capacity of 1000J, how long will it last?
    The answer will depend on how you are using the battery.
     
  6. Jan 31, 2010 #5

    Nabeshin

    User Avatar
    Science Advisor

    Re: Energy <---> Mass conversion and visible light

    If we are going from energy -> matter, then it seems to me we are essentially going from photons -> matter. So why would photons be emitted during the process?
     
  7. Jan 31, 2010 #6
    Re: Energy <---> Mass conversion and visible light

    lets see if I can fine tune my visualization...
    Going from Mass to Energy E=MC^2, fission, light is noticed by the observer, thinking of an atomic bomb explosion. Then, reversing the process, M=E/C^2 going from Energy to Mass, fusion, light is also noticed by the observer. Thinking about the process going on in the Sun. what is going on in the Sun is dependent on preexisting mass, the hydrogen atom. Is it possible to theoretically apply a source of energy independent of preexisting mass?
     
  8. Jan 31, 2010 #7

    Nabeshin

    User Avatar
    Science Advisor

    Re: Energy <---> Mass conversion and visible light

    That's not what happens. Fusion is not conversion of energy into mass. Fusion and fission both operate on the principle that you take some atoms, perform some reaction, and the resultant atoms have less mass than the starting atoms, the difference in mass expressed as the binding energy of the atoms. This binding energy is released as energy (in particles, or in gamma radiation [light]).
     
  9. Jan 31, 2010 #8
    Re: Energy <---> Mass conversion and visible light

    Thanks for the clarification on Fusion vs. Fission. Let me see if I understood you correctly... the Energy in E of the M=E/C^2 equation is dependent on preexisting Mass?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook