Perpetual motion machines are a thing of fantasy/delusion, but there’s a lot of energy floating around that doesn’t cost anything to harvest. The calculator and weather station shown here run off of microwaves from that TV tower in the distance.
Broadcasters pump out tons of of RF from their big microwave towers, operating on the mere hope that some of the RF will hit a TV antenna and deliver unto someone the evening news. Since power demands for electronic devices continues to reduce (see Moore’s Law), those radio waves can now act as currents in a stream, turning the digital wheels inside small electronic devices. Read More.. [via gizmodo]