Maxwell’s demon faces the heat | Science News


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Maxwell’s demon faces the heat

Test of second law of thermodynamics shows that manipulating energy comes at a price

7:00am, December 1, 2015

Anyone trying to circumvent the physical laws governing heat is going to get burned.

A new experiment reveals how a device that robs a closed system of heat to make it more orderly, an action forbidden by a bedrock law of physics, inevitably pays a price by becoming hotter and more disordered. It’s a real-life demonstration of a nearly 150-year-old thought experiment known as Maxwell’s demon. If this demon really could skirt the second law of thermodynamics — which states that the entropy, or disorder, of an isolated system can never decrease ­— then it would be possible to create a perpetual motion machine.

The demonstration described in a paper to be published in Physical Review Letters is the first to monitor both a system and the demon that’s working to reduce the system’s entropy. “It’s a really nice experiment,” says Eric Lutz, a theoretical physicist at

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