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RE: Maxwell's Demon: Violation of The Second Law of Thermodynamics
That is a very interesting thought experiment.
I kept thinking how this hypothetical being (Maxwell's Demon) would need energy in order to observe, perceive, decide and perform all those tasks (processing information - opening and closing the gate etc).
Even if we could create some sort of artificial intelligence, with say all technical requirements and equipment necessary to observe and measure the precise temperature and speed of molecules, wouldn't it still need some sort of external energy source in order to operate? Just a few thoughts.
Thank you for this wonderful read.
@lordneroo, Excellent question!
Yes, the process of measuring the temperature and opening/closing of the door requires some finite amount of energy. There are two aspects of this, energy consumption and entropy generation. Let's tackle them separately.
In principle, there isn't a theoretical limit for the energy required to open/close the door and for the measurement. The door can be made arbitrarily small and with appropriate material, its mass can be close to zero. Let's say the demon generates a thermal potential energy of 50 Joule by switching the molecules but in principle, the energy required for opening/closing the door (and of course the measurement) can be less than 50 J. There isn't any law of physics that doesn't allow this to happen. Hence, the second law fails (if we don't consider the role of the demon's memory).
Entropy generation is another problem of door opening/closing and measurement process. The second law tells us that either entropy has to remain constant or it has to increase. The demon lowers the entropy of the system by reducing the disorderness. So according to the second law, at least an equal amount of entropy has to increase to compensate the entropy reduced by the demon. Naturally, we think that the mechanical operation of door opening/closing and the measurement process increases the entropy. In real life, those operations indeed increase entropy but in principle, we can do those operations without increasing any entropy! Again the second law fails( if we don't take consider the entropy generated to erase the demon's memory).
Thanks for passing by. I love your Cartography series :)
Hey @anevolvedmonkey, thank you so much for taking the time to leave such a detailed, lengthy response. I truly appreciate that! Thanks for clarifying things and keep up the quality work.
PS: Thank you so much for your kind words regarding my work. The same goes to you of course!
Take care ! :)