Light is fast, but travels in long wavelengths and interacts weakly with itself. The particles that make up matter are tiny and interact strongly with each other, but move slowly. Together, the two ...

The main differences between bipolar 1 and bipolar 2 are the severity of manic episodes, and whether or not someone experiences depression.

A quarter of coupled-up Americans say their partner is their “polar opposite.” That’s according to a new survey of 2,000 ...