The Wirbelrohr’s Roar: A Thermodynamic Curiosity

A remarkable device, with no moving mechanical parts or any connection to a source of electrical energy, appears to defy the Second Law of Thermodynamics by simulating a Maxwell demon and producing simultaneous, oppositely directed streams of hot and cold air from an input air stream at room temperature. I learned of the device while playing chess with my father-in-law who constructed such a device (a Wirbelrohr) many years earlier after reading about it in a science fiction magazine. But the device is no fiction. My simple analysis shows that the Wirbelrohr violates no laws of physics.

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