HBO’s sci-fi hit is a hotbed for theories about secret plots, twists, and timelines. Who’s actually an android? When is this happening? A guide to the seven biggest theories.

Quantified Self

There are dozens of fitness gadgets on the market that can measure movement, heart rate, elevation, and even body temperature. Here’s how to figure out which will work for you.

Self-Driving Car!

A self-driving car. A device that tells you you’re eating too fast. Space-age innovations from the Consumer Electronics Show.