I was reading about steamships. It was a wonderful article in which the author said that the dream of a self-propelled ship had been a dream of humankind for hundreds of years. Then one day the time came when it was theoretically possible, but it was still not practically possible. The dream was kept alive for another hundred years or so by inventors and experimenters, some of whom were considered to be eccentric. Later on people looked back and said of them, they were just ahead of their time.

Then th…