Three Flavors of Impossible: Telepathy, Time Travel, and Perpetual Motion Machines

"Physicist Says Time Travel Is Not Only Possible, but Likely"
FOXNews (April 2, 2008)

A professor at the City University of New York, Michio Kaku, has a new book, "The Physics of the Impossible." He may also be a good businessman. In America, at least, putting outlandish ideas into a book is a pretty good way of selling books.

On the other hand, the professor says (repeating common sense for speculators from decades ago) that there are three kinds of "impossible" things:

1. Possible soon
2. Possible in the far future
3. Really, truly impossible

The article is pretty good light calisthenics for the brain.