Given how large the green bandwagon has become, it's no real shock to see an energy-saving concept from the 1930s being exhumed and investigated further. Scientists at Oxford University have begun to take a closer look at an early invention from the great Albert Einstein in order to hopefully create refrigerators (and appliances in general) that could be used completely without electricity. Back in the day, Sir Albert created a mechanism that had no moving parts and used only pressurized gases to keep things chilly. Once compressors became more efficient in the 50s, however, the idea was tossed aside. Now, the idea obviously has greater appeal, and if things keep humming along nicely, a completed prototype should be erected by the year's end.