Only tachyons can save us now!

Note to the Reader: For those of you who haven't seen Fantastic Four:
Rise of the Silver Surfer, yet are serious enough about it that you
want even the most trivial plot details kept secret until you actually
watch the movie, what follows will be a bit of a spoiler. (A rough
calculation makes us think there are about three of you out there.)
For the rest of you, don't worry, this little detail won't ruin
anything.

So, Reed Richards, aka Mr. Fantastic, is sitting in his lab trying to
think of a way to separate an alien from his cosmic surfboard when he
gets an idea. "A tachyon burst!" he exclaims.

Fast-forward a few scenes. A series of devices capable of delivering
said burst are built, one is activated, and the aforementioned alien,
known as the Silver Surfer, is cleanly knocked from his board.

Now, would this really work? Tachyons are theoretical particles
believed to travel faster than the speed of light. Trying to think
about what effect they would have on a liquid-silver alien can be
thoroughly mind-bending—would they send him back in time or even
arrive at their target in the past, thus having no effect whatsoever?
So, we appealed to University of Washington physicist and science
fiction author John G. Cramer, who has the scientific and imaginative
chops to handle such questions.

First, Cramer notes that knocking the surfer off his board would
require a transfer of momentum. And while the momentum of the
hypothetical tachyon beam would be relatively small, there might be
another, more dramatic effect. "The delivery of energy would be much
more efficient than the delivery of momentum," Cramer says, "so it
seems more likely they would blow the Silver Surfer apart rather than
knock him around."

Instead, Cramer proposed another, decidedly less-sexy idea. "I think a
cannonball or an artillery shell would work a lot better."

So, Mr. Fantastic, next time you try to save the world, do it the
old-fashioned way.—Gregory Mone