A product of our times: on-demand shooting stars. Going to market to find new species of sharks. It s in the genes: Why some people need very little sleep. And movies about time travel, ranked.
Photo: Arnold Schwarzenegger attends a press event for Terminator Genisys on June 1, 2015 in Rio de Janeiro, Brazil. The Terminator movies involve time travel. (Raphael Dias/Getty Images for Paramount Pictures International)
