What was strange, the pilots said, was that the video showed objects accelerating to hypersonic speed, making sudden stops and instantaneous turns — something beyond the physical limits of a human crew.

“Speed doesn’t kill you,” Lieutenant Graves said. “Stopping does. Or acceleration.”

The only direct communication I have with my fellow [email protected] users is the crowd-verification icon that appears after people review my photos. One such acknowledgment suggested my generic geranium observation near Golden Gate Park was actually a geranium robertianum, commonly known as Wren flower, or Death come quickly (a plant I won’t soon forget). It was a silent smile, passed between nature lovers.

Upper-middle-class children are far better placed even before their parents make any special effort, simply because of the sort of homes they are born into. Educated parents tend to respond readily to their children’s endless questions, talk to them over the dinner table and take them to new and exciting places. In a famous study in the 1990s, Betty Hart and Todd Risley from the University of Kansas found that in the poorest families children heard about 600 words an hour, whereas in professional families they heard 2,100. By the time they were three, the children from the well-off homes had heard around 30m more words than the poorer ones.

Ron Williams, former chief executive officer of Aetna, thinks the burden should be on Google to ensure accuracy, not the individual.

Mr. Williams, who serves on the boards of Boeing, Johnson & Johnson and American Express, has been promoting his new book “Learning to Lead,” a tome on executive management. His Google panel, featuring his head shot, also until recently incorrectly credited him for “Miami Heat Wave,” a photo collection of muscular men in their underwear, and “Faith & Fat Loss: God’s Way To Permanent and True Transformation.”