How Do Vending Machines Detect Fake Coins? This machine can decipher coins with pinpoint accuracy. Light sensors measure the size while electromagnets detect the metal type of the coin. Facebook Prev Article Next Article Discover Checkout these cool gadgets... Related Posts Will We Ever Run Out of New Music? 6 Times Scientists Radically Misunderstood the World A Crash Course in Psychology This Quantum Lab Makes Exotic States of Matter in Space World’s Notoriously Painful Plant – The Gympie-gympie What Would Happen If You Never Showered?