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Q & A: feeling the heat

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Most recent answer: 09/26/2014
Is the heat we sense when touching a hot object result from the vibrating molecules colliding with the molecules in our skin? Are photons released? Does the energy of heat overcome the nuclear forces that hold the molecules together?
- Donna (age 48)

Yes, mainly the heat is transferred via one vibrating molecule rattling another. Some low-frequency infrared photons are also constantly being emitted and absorbed, so that's another heat transfer path. Those photons are the ones that make us show up on infrared night-vision cameras.

The name "nuclear forces" refers to the forces holding the particles in a nucleus together. Body temperature isn't even close to being high enough to tear apart nuclei. Perhaps by "nuclear forces" you mean the forces holding atoms and molecules together, involving the states of their electrons. That would be asking, in other words, if chemical reactions occur at body temperature. They certainly do. Thermal energy can tear apart molecules. 

Mike W.

(published on 09/26/2014)

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