Briefs: A comeback for Einstein’s fridge?
Scientists at Oxford University have rebuilt one of Einstein's early inventions in an attempt to develop an environmentally friendly refrigerator that runs without electricity. They have built a prototype of a fridge patented in 1930 by Einstein and his colleague Leo Szilard. It has no moving parts and uses only pressurized gases to refrigerate. The original refrigerators were used until supplanted in the 1950s by more efficient models using compressors and freons. Einstein's fridge used ammonia, butane (in the evaporator) and water and took advantage of water's lower boiling temperature when the pressure was lowered. Current research is focused on ways of improving the efficiency by replacing the gases (expected to quadruple the efficiency) in the fridge and hopes to power it with solar energy. The fridge will be maintenance-free because it has no moving parts, and this will be of vital importance in rural areas.