The Greatest English Language Science Fiction Writer?

The shift from H.D. Wells and the English or British scientific romance to science fiction started in the 1890s. In 1929, you get astounding science fiction, which is often considered to be the home of American engineer, hard science fiction. So it's very important that people writing in that have a kind of authority training in science. And then another figure I would add, who's probably more important than all of those three, virtually, is Robert Heinlein.