Humans may, one day, be able to inhabit other planets. Some advocates argue that remaining on only one courts disaster.

A man visited a hospital because of bladder discomfort, and his doctors discovered a remarkably large bladder stone.

They’re like living feather dusters whose mouths can see you coming. The simplest animal eyes consist of light-sensitive cells, partnered with a dark pigment. These give their owners a one-pixel sense ...