The Boston Dynamics video from October 2013 begins with a wide pan across a mountainside in Southern California’s Mojave Desert. Slowly, the viewer’s eye picks out two shapes inching their way up the uneven terrain: a man and a robot.

The robot is Boston Dynamics’ LS3, a horse-sized machine that picks its way daintily up rocky slopes and snow-laden hills, despite the 400 pounds of baggage it is capable of carrying on its back. Like the company’s more famous BigDog and Atlas, LS3 is made for locomotion, even over the toughest terrain.

When Google bought Boston Dynamics last week, that’s the technology that it acquired. Along with taking on rough ground, Boston Dynamics’ robots are fast and able to overcome the unpredictable. Its CHEETAH bot holds the world record for the fastest legged robot, logging a top speed of 29 miles per hour. BigDog can recover from a…