Off topic: Sailing stones, power in numbers, Chinese siblings, sci-fi art

One of several hundred rocks that have left trails as they moved across the surface of Racetrack Playa in California's Death Valley National Park on August 18, 2014. There were several theories for the strange activity, but Richard Norris, a paleobiologist at Scripps Institution of Oceanography, and his cousin James Norris, a research engineer, were the first to photograph rocks in motion. (Louis Sahagun/Los Angeles Times/MCT)

PUBLISHED: August 28, 2014 at 11:18 p.m. | UPDATED: August 12, 2016 at 7:10 a.m.

ICYMI, the mystery of the sailing stones at Death Valley has been solved: Everything has to be perfect. Does walking in formation make men feel more powerful? A photo essay about a family with seven children… in China. And sci-fi art from the 70s, a Tumblr.

Photo: One of the sailing stones leaves trails as it moves across the surface of Racetrack Playa in California s Death Valley National Park on August 18, 2014. (Louis Sahagun/Los Angeles Times/MCT)