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Article: Demons, engines and information: can a clever 'demon' outsmart the second law of thermodynamics?
- Article from:
- Science News
- Article date:
- June 16, 1990
- Author:
CopyrightCOPYRIGHT 1990 Science Service, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Demons, Engines and Information
No one expects a refrigerator to keep its contents cold without the expenditure of energy. The second law of thermodynamics sees to that. Because heat doesn't spontaneously flow from a colder to a hotter body, it takes energy to extract heat from a refrigerator to make it cold.
But is that always true? In 1871, the Scottish physicist James Clerk Maxwell considered the idea that a microscopic being, small enough to see and handle individual molecules, might be exempt from the second law.
Maxwell envisioned such a creature standing at a small hole in a partition dividing a gas-filled box into two compartments. By ...