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suppose that we have single body say sphere and nothing else in the universe. Now it will radiate heat depending on its temperature.since its energy is going down its temperature will decrease.Eventually wel have energy in the form of photons and sphere at zero kelvin. thus In practical case, if we reduce the incoming radiation and increase the out going radiations by sutaibly choosing absorptivity and emissivity we will achieve heat transfer from body at lower temperature to body at higher temperature.

let us consider two infinite parallel plates P1 and P2 with vaccum in between them so that only radiation takes place between them

plate 2 is held at temperature t2.

Let us assume the following

Plate 1

Absorptivity a1 = 0.1

Emissivity e1 = 0.9

Temperature t1

Plate 2

abosrptivity a2 = 0.9

emissivity e2 = 0.1

Temperature t2

Then Consider a steady state

I claim that the steady state temperature of Plate 1 is not equal to t2

for steady state the Incoming heat on Plate 1 must be equal to outgoing heat.

Incoming heat = abosrptivity * radiation from plate 2

= 0.1 * 0.1* sigma* t2*t2*t2*t2 ---------equ1

where sigma is stefan Boltzmann constant = 5.67 exp(-8)

Outgoing heat = emissivity * BlackBody radiation at that temperature

= 0.9 * sigma * t1*t1*t1*t1 ------------ equ 2

Thus equating above 2 equations

0.1 * 0.1 * sigma t2*t2*t2*t2 = 0.9 *sigma *t1*t1*t1*t1

Thus we get

0.325 * t2 = t1

Thus if initially both bodies were at same temperature then more heat will leave plate 1 and thus cause cooling without any input of work.

this way we would be violating second law of Thermodynamics.

Note

It is observed that reflection effects cancel each other and are energy associated with reflection is quite low.

The materials with above mensioned properties are available.

we even considered spectral distribution of Emissivity and Absorptivity and found that overall emissivity or overall absorbtivity values of 0.1 or 0.9 can be obtained.

Final word

Can radiation effects violate second law of thermodynamics.