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Is there a difference between photons from a light bulb and photons from the sun?

  1. Dec 30, 2011 #1
    Photons activate hormones in us which cause us to wake up. I'm wondering if there is a different between the photons coming from the sun and the photons coming from a light bulb? Do these both have the same effect on the body?

    I've put this in the classical category because of optics.
  2. jcsd
  3. Dec 30, 2011 #2


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    Photons are photons are photons.

    Of course, a light bulb emit photons at different rates and depending on the type of bulb, relatively different spectra of light.
  4. Jan 2, 2012 #3
    They definitely have a different biological effect on humans because the light bulb is missing many frequencies that are found in sunlight. You can buy bulbs that produce a spectrum that is pretty much the same as sunlight. Of course you don't want the UV in your house. You can see the difference if you take photographs, especially using film, in sunlight, in incandescent and fluorescent light. In fact I recall buying special film to use for indoor photography.

    So photons have variable energy depending on their frequency i.e. color for visible and they have brightness or intensity depending on just how many photons there are. People with seasonal affective disorder become quite depressed in the winter in areas that have low light and show significant improvement when expose to bright lights. I can recall a difficult time in my life when I used to go to KMart at night and just walk around because the bright light made me feel better. And improvement in a depressed person who has SAD is documented. At least we don't turn green from the added light.
  5. Jan 2, 2012 #4
    Look up circadian photoreceptors.

    An incandescent lamp will not wake you up as fast as sunlight because they don't emit much blue light.
  6. Jan 2, 2012 #5
    And people who sleep with lights in their bedroom have a number of health related issues a person who sleeps in a totally dark room does not have.

    We're programmed to sleep best when it's very dark. A friend went to Alaska in the summer when there was no dark and she had to put foil over her windows and wear a black mask because she was having all sorts of serious mental problems as well as physical problems from the lack of darkness.
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