![]() “On peut résoudre de deux façons différentes cette contradiction avec le second principe de la Thermodynamique. To avoid a conflict with the second law, Wien proposes two solutions (original quote in French) : In any case, it is instructive to continue with Wien’s reasoning, and then discuss Rayleigh’s correction. This error is corrected by Rayleigh as described further below. He concludes that B receives three times more energy than A. Wien then carelessly assumes that this polarized light crosses nicol Y and reaches B. The second half is rotated by 45˚ and as it reaches nicol X, is totally reflected toward B. Half of the light coming from B is reflected back to B by nicol Y. ![]() The other half undergoes a 45˚ rotation, traverses nicol Y and reaches black body B. Half of the light coming from A is reflected back to A by the nicol X. The analysis is illustrated in Figure 1 in which the width of the channels corresponds to the magnitude of heat flow. Wien’s analysis assumes that the black bodies are initially at the same temperature. ![]() The polarizers are nicol prisms which, he assumes, transmit half of the light and reflect the other half. He describes a thought experiment involving two black bodies A and B separated by a Faraday isolator comprised of polarizers X and Y and a Faraday rotator R. Wien attempts to prove that Faraday isolators cannot violate the second law. The unidirectionality of the device seems to indicate that objects downstream of the light flow should get warmer and those upstream should get colder. Light entering through the output is polarized, and then rotated another 45˚ thereby, encountering the first polarizer at a 90˚ angle and being stopped. Light entering the isolator through the input is linearly polarized, then rotated by a 45˚ angle and exits unimpeded through the output polarizer. It comprises an input linear polarizer, a polarization rotator and an output linear polarizer at 45˚ from the input polarizer. The Faraday isolator is a non-reciprocal optical device, i.e., a light diode. This paper discusses how such non-reciprocity leads to the breakdown of detailed balance and the second law. Non-reciprocal devices are used in a multitude of applications, for example Faraday isolators and optical and microwave circulators. This law is conventionally accepted, yet non-reciprocity of transmission and reflection has been the puzzlement to scientists as it appears to violate the principle of detailed balance and the second law. Reciprocity in absorption and emission is a requirement of detailed balance and expressed by Kirchhoff law of radiation for any wavelength and for any direction.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |