It looks like the father of modern physics had more up his sleeve than the theory of relativity. Long after he changed the landscape of modern physics, Albert Einstein and his former student Leo Szilard patented a refrigerator that had no moving parts and used only pressurized gases for cooling. It got overshadowed 20 years later, in the 1950s, when more efficient, if environmentally-damaging, freon-compressors for refrigerators became available.

Every branch of science has at some point been confronted by a daunting question that stumps progress for years, even decades. How did the continents form? What causes fever? Is there intelligent life beyond Earth?