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How the Sun warms the Earth?

  1. Apr 6, 2015 #1
    The sun radiates its energy in all directions by emitting photons. As the photons travel as electromagnetic waves it reaches the earth. The photons collide with atoms and molecules in the atmosphere due the collision the energy of photons are emitted as heat. The atmosphere is thus heated and it heats the surface too. Thus the sun warms the earth...
  2. jcsd
  3. Apr 6, 2015 #2


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    Welcome to PF!

    So, that all sounded about right; did you have a question about any of it?
  4. Apr 6, 2015 #3
  5. Apr 6, 2015 #4


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    Much of the sun's radiation reaches the surface of the earth directly, while only a fraction heats up the air.
  6. Apr 6, 2015 #5
    The photons not only collide with atmospheric molecules it also collides with the surface... In atmosphere the photons are free to move so most of the photons reaches the surface... Hence it collides more in surface and produce more heat in surface... Thus the most of radiation reaches the surface...:-)
  7. Apr 7, 2015 #6


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    forget about individual photons .... its going to lead you down a bad path of confusion

    Do you understand that it is infra red that is the primary cause of heating ?
  8. Apr 7, 2015 #7
    Bro, infrared is an electromagnetic wave which is due to the photons... infrared is the cause for heat.. Not only the infrared, ultraviolet can also produce heat.. That's why I had said photons are cause for the heat which are the basic constituents of all electromagnetic radiations... Is there anything u want to say...?
  9. Apr 7, 2015 #8


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    Good that you sort of know what IR is ... your previous posts didn't hint at that, hence why I asked
    just to get you on the right path, EM isn't due to photons
    yes I repeat .... in this context, forget about the individual photons stuff, just stick to EM radiation/waves
  10. Apr 7, 2015 #9
    But I heard that EM are due to photons...!
    Is it wrong...?
  11. Apr 7, 2015 #10
    Light can be considered either as a particle or a wave.
    Depending on what we are trying to achieve sometimes it's best to consider light as photons, other situations make more sense to consider EM as waves.
    The relationship of these two distict ways to view EM, both of which are valid, is what lies at the heart of quantum mechanics.
  12. Apr 7, 2015 #11
    U r
    absolutely rit I think.
  13. Apr 7, 2015 #12
    Actually photons r amazing and mysterious thing... Which acts like both wave and particle...
  14. Apr 7, 2015 #13


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  15. Apr 30, 2015 #14


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    I believe I understand what you are getting at, but I STRONGLY disagree with your statement as written. Light is NOT a particle and light is NOT a wave. Light is a quantum object that has both particle-like characteristics and wave-like characteristics. Particles and waves are classical physics objects and light is not either one.

    I assume that this is what you actually mean (that it "acts" like one or the other, not that it "is" one or the other).
  16. Apr 30, 2015 #15
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