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Q & A: thermal radiation isolation?

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Most recent answer: 03/03/2011
Q:
can we prevent a body from emitting and absorbing radiations except for making temperature difference between body and surrounding equal to zero?can we isolate a body from universe so that no interactions take place?
- tapas (age 17)
patna,bihar,india
A:
Good question.

There really is no way of 100% isolating objects. There's always a little bit of interaction with electromagnetic fields. Even superconductors have a tiny concentration of thermal quasi-particles, providing some interaction between electromagnetic fields and other types of thermal energy. In practice, however, thermal isolation can work well enough for practical purposes. Even though the thermal radiation in the universe is at about 2.7K, even simple cryostats can cool things well below that. Ordinary metal shields are quite effective at the wavelengths of this thermal radiation.

Mike W.

(published on 03/03/2011)

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