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Einstein, 1930 and US patent 1781541
Just read this really interesting fact that I never knew.
The patent was for a refrigerator.
Fridges seem to work despite the second law of thermodynamics, which says that heat always flows from a hotter to a colder body in a closed system. The get-out clause is ‘in a closed system’. A refrigerator gets away with it by consuming energy in order to pump heat to the outside, where it emerges from the radiator, usually located on the back.
When Einstein and Szilard invented their fridge, most current refrigerators operated using a poisonous gas as the refrigerant, which was kept under high pressure – an accident waiting to happen. In the 1920s, a German family was killed when the seal broke on the refrigerator and the gas escaped.
This led Einstein and Szilard to come up with a fridge design where there were no moving parts and the coolant was kept under constant pressure. It used a mix of two compounds, one of which could be quickly extracted to drop the pressure and hence the temperature. Einstein is usually thought of as unworldly and impractical, but he did have considerable experience of inventions from when he worked in the Swiss Patent Office.
This design is not widely used, but it has the advantage for developing-world applications of working with any source of heat, not just electricity.
Source: Clegg, Brian. “How Many Moons Does the Earth Have?"
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