• Xero@lemmy.worldOP
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    1 year ago

    How does heat get from the water radiator to the air?

    Radiation.

    The fan blowing on the radiator: Excuse me?

    • Iron Lynx@lemmy.world
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      11 months ago

      This. And what heat exchange mechanisms are in play when you have a moving fluid? That’s right! Convection!

      (And a bit of conduction at the boundary layer, but I already shut off a different fork of this thread by limiting pedantry)

    • Blue_Morpho@lemmy.world
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      1 year ago

      The fan blows air on the radiator. Those air molecules can’t physically touch the radiator. The electostatic forces of atoms keep everything separated. When you touch something, you are feeling the electrostatic force of your finger’s atoms pushing against the electrostatic force of the object’s atoms.

      The electrostatic force (that is the electro magnetic force that electrons radiate) is actually photons. The particle of electromagnetism is the photon. When you touch something you are feeling the photons exchanging between the electrons in the atoms of your fingers and the object.

      The definition of radiation is photon emission/absorption.

      • Iron Lynx@lemmy.world
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        11 months ago

        and in convection, at what point are photons being exchanged?

        How about in conduction?

        I’m pretty sure both of those are just ripples of heat in atoms & molecules spreading to nearby atoms & molecules via more nano-mechanical means, with the former case having that amplified by the fact the atoms & molecules are in motion at a larger scale.

        Loosely couple two identical oscillators and excite one, and the second will move as well, no photons needed. At a nano scale, that is how conduction works. And again, convection adds to that the fact that the oscillators can freely move around each other

        • Blue_Morpho@lemmy.world
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          11 months ago

          Loosely couple two identical oscillators and excite one, and the second will move as well, no photons needed.

          At the atomic level, nothing physically touches. Electrons do not physically touch each other to transfer momentum. When two atoms get close, the electromagnetic field pushes the electrons away from each other before the electrons touch.

          The electromagnetic field is made of photons.

          https://en.m.wikipedia.org/wiki/Photon