Physicist Says Time Travel Is Not Only Possible, but Likely

Time travel? Teleportation? No problem, says renowned physicist Michio Kaku.

Kaku, a professor at the City University of New York, is creating quite a stir in Britain with the release of his new book, "The Physics of the Impossible."

On this side of the pond, outlandish claims in books are recognized as, well, a good way to sell books.

But in Blighty, Kaku's being treated as if he's Doctor Who informing dim-witted humans about the wonders of the Universe, with front-page treatment Wednesday in both the Daily Telegraph and the Guardian. Even the normally staid Economist is chiming in.

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Kaku, one of the earliest proponents of string theory, still a contentious issue among physicists, divides the most common science-fiction tropes, or "impossibilities," into three categories — possible soon, possible in the far future and really, truly impossible.

Category 1, as he dubs it, includes things that may become true within the next century, if not the next few decades: teleportation (already possible, but only among subatomic particles); telepathy (thanks to brain implants); invisibility (already being researched using light-bending 'metamaterials'); laser guns (existing, but hugely power-hungry); force fields; and the discovery of extraterrestrial life.

Category 2 includes things that are theoretically possible but would be realized only with thousands more years of technological progress: time travel (possibly through "wormholes" in space); traveling faster than light; and the discovery of parallel universes.

Category 3 consists of things that really are impossible because they violate the laws of physics. Only two concepts qualify: knowing the future and perpetual motion.

"The Physics of the Impossible," released March 11 in the U.S., is currently No. 123 on the Amazon bestseller lists. It comes out Thursday in Britain, though without the "Doctor Who"-themed cover of the U.S. version.

• Click HERE to read the Telegraph report, HERE for the Guardian write-up, HERE for a review in the Seattle Times and HERE for a brief online-only interview in the New York Times.