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theDoc
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Rectennas are diodes attached to antennas. With current technology they can convert EM waves with frequency up to [tex]\approx[/tex] 1 THz to electricity.
Imagine an isolated room at 300[tex]^{o}[/tex] K containing a black object and a rectenna. By Planck law, the black object radiates about 450W/m[tex]^{2}[/tex], of which about 1/10,000 is of frequency less than 1 THz. Couldn't this .045W/m[tex]^{2}[/tex] be captured from the waste heat, in contradiction with the 2nd law of thermodynamics? For e.g. use this electricity to heat another room and create a temperature differential
Imagine an isolated room at 300[tex]^{o}[/tex] K containing a black object and a rectenna. By Planck law, the black object radiates about 450W/m[tex]^{2}[/tex], of which about 1/10,000 is of frequency less than 1 THz. Couldn't this .045W/m[tex]^{2}[/tex] be captured from the waste heat, in contradiction with the 2nd law of thermodynamics? For e.g. use this electricity to heat another room and create a temperature differential