It’s easy to understand the theoretical minimum temperature: absolute zero. The absolute maximum, on the other hand, is squirrely. “We just don’t know whether we can take energy all the way up to infinity,” says Stephon Alexander, a physicist at Dartmouth University. “But it’s theoretically plausible.”
You are unique. This is one of the more obscure ways you're unique: An alternating current of different frequencies running through you causes a reaction that's noticeably different from anyone else's. Researchers from Dartmouth University are trying to put this difference to use by creating wearable electronics that respond to - and only to - their intended user.