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Light spectra

  1. Jan 22, 2017 #1
    Hello everyone, I have a couple of theoretical questions concerning light spectra and different sources of light. I need the informtion for a paper I am writing for my physics class. I have been googeling around all day without finding the information, I am looking for.
    1. A star has a high temperature, and therefore a continuos spectrum rather than an emission spectrum. Can you find out which elements created the light form a star by looking for iregularities in a star's light spectrum?
    2. The Stefan-Boltzmann law works for black objects only. But a body at absolute zero would have no energy, and therefore emit no energy, and I pressurme that it would, in consequence, be black. Therefore: does this law work for every object?
    3. Using the Stefan-Boltzmann law, I have tried to calculate the temperature of the objects: the sun, a light bulb and blue light from a machine.:
    I have calculated that the sun has a temperature of about 6000 K, which I believe to be right.
    I have calculated the temperature of a light bulp to be about 5000 K. That seems somewhat high, doesn't it?
    The blue light is calculated to more than 6000 K, which in my oppinion makes no sense, as it is not an
    incandescent bulb.
    I really hope that you can help me!
    Thank you very much in advance!
  2. jcsd
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