Robot dog runs a marathon on a single battery charge

A four-legged robot has completed the Sangju Marathon in South Korea alongside human runners, finishing in a respectable 4 hours, 19 minutes. The Sanju course is notoriously difficult, with large elevation changes and slippery sections – yet the robot was able to finish the whole thing with enough charge leftover to run another half-marathon. The robot has about three times the range of existing four-legged robots, and potentially more energy efficiency than a human – which the researchers say i