Quarters are the largest coin in typical US currency (and no, this doesn’t include the golden dollar or half-dollar piece). This team with PBS’s show Physics Girl with Arc Attack decided to shrink the quarter down to half its size. The tool? High-powered electromagnets.
They charged a capacitor to 8,000 volts, then passed the current through a coil around the quarter. Physics Girl Dianna Cowern does an awesome job of explaining the physics behind the shrinking and the potential dangers of trying to recreate this experiment elsewhere.
Via Physics Girl