Brainy Quote of the Day

Wednesday, May 3, 2017

The Quantum Thermodynamics Revolution...

Ricardo Bessa for Quanta Magazine
Topics: Black Holes, Information, Quantum Mechanics, Theoretical Physics, Thermodynamics

Zeroth Law of Thermodynamics
1st Law of Thermodynamics
2nd Law of Thermodynamics
3rd Law of Thermodynamics

Dicebat Bernardus Carnotensis nos esse quasi nanos gigantium humeris insidentes, ut possimus plura eis et remotiora videre, non utique proprii visus acumine, aut eminentia corporis, sed quia in altum subvehimur et extollimur magnitudine gigantea - Bernard of Chartres used to say that we were like dwarfs seated on the shoulders of giants. If we see more and further than they, it is not due to our own clear eyes or tall bodies, but because we are raised on high and upborne by their gigantic bigness. Source: Wikiquote, John of Salisbury.

In his 1824 book, Reflections on the Motive Power of Fire, the 28-year-old French engineer Sadi Carnot worked out a formula for how efficiently steam engines can convert heat — now known to be a random, diffuse kind of energy — into work, an orderly kind of energy that might push a piston or turn a wheel. To Carnot’s surprise, he discovered that a perfect engine’s efficiency depends only on the difference in temperature between the engine’s heat source (typically a fire) and its heat sink (typically the outside air). Work is a byproduct, Carnot realized, of heat naturally passing to a colder body from a warmer one.

Carnot died of cholera eight years later, before he could see his efficiency formula develop over the 19th century into the theory of thermodynamics: a set of universal laws dictating the interplay among temperature, heat, work, energy and entropy — a measure of energy’s incessant spreading from more- to less-energetic bodies. The laws of thermodynamics apply not only to steam engines but also to everything else: the sun, black holes, living beings and the entire universe. The theory is so simple and general that Albert Einstein deemed it likely to “never be overthrown.”

Yet since the beginning, thermodynamics has held a singularly strange status among the theories of nature.

“If physical theories were people, thermodynamics would be the village witch,” the physicist LĂ­dia del Rio and co-authors wrote last year in Journal of Physics A. “The other theories find her somewhat odd, somehow different in nature from the rest, yet everyone comes to her for advice, and no one dares to contradict her.”

Quanta Magazine: The Quantum Thermodynamics Revolution, Natalie Wolchover

Related link

Physics arXiv: Quantum Thermodynamics
Sai Vinjanampathy, Janet Anders

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