Potentiometer, an electrical device that measures potential difference between two points in a circuit by comparison with a standard battery of known potential difference. The name is also applied to a variable resistor that provides varying amounts of potential difference.
We first reported on the possibility of an invisibility cloak last year. Now a different invisibility cloak is making the news -- one that uses metamaterials to redirect light away from the wearer.
Whether they're sorting out scrap metal or helping us unlock the secrets of the universe, electromagnets are pretty nifty devices. What's so great about magnetism on demand? We'll electrify you with the details in these videos.