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B Why we don't use visible light to cook food?

  1. May 11, 2017 #1
    As we know that microwaves have less energy than visible light , then do we use microwave oven in cooking food instead of visible light?
  2. jcsd
  3. May 11, 2017 #2


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    Gold Member

    I'm pretty sure its because microwaves transfer energy to water molecules very efficiently. If you shine a micro-wave emitting flashlight on some water, it will heat up a lot more than if you shine a visible light emitting flashlight at some water.

    Its about the specific frequency of the photons and that matching what water molecules will absorb.

    Edit - I did some post-posting Googling (barn door after horse) and I am wrong. Its more about being able to generate enough power at a convenient frequency and how far into the food the radiation can penetrate as its dissipating its energy - not about making water molecules vibrate at some specific frequency.
    Last edited: May 11, 2017
  4. May 11, 2017 #3
    Normal sources of visible light are not high enough intensity unless you use a laser. You can use sunlight to cook although about half is infra red. .Another issue is that visible light does not penetrate material so cooking would only be on the surface you would have to rely on conduction to cook the inside.
  5. May 11, 2017 #4
    x-rays have even more energy per photon. Why do you think they are not used for cooking? I can think of more than one reason.
  6. May 11, 2017 #5
    Some years ago I saw an advert for a Pizza oven that used light sources for cooking. The ad claimed that they were faster blah blah. I did a quick search but as you can imagine "White light pizza oven" did not return anything useful.

  7. May 11, 2017 #6


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    Science Advisor

    Try a different search term... https://en.wikipedia.org/wiki/Easy-Bake_Oven
  8. May 14, 2017 #7
    What is the reason?
  9. May 14, 2017 #8
    Why microwaves transfer energy to molecules more efficiently?
  10. May 14, 2017 #9
  11. May 15, 2017 #10
    In addition to the above, microwave ovens work by creating a microwave cavity inside.
  12. May 15, 2017 #11


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    Staff: Mentor

    Note that infrared radiation is used at least in conjunction with convection for grilles.
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