Beams of Light Could Steer Future Spaceships
NOVA - 09/19/2013
Picture this: A spaceship—nothing out of the ordinary, except for the spinning glass rods mounted at the corners—that can be steered by nothing more than light.
While that application may be a long ways off, physicists at MIT and Northeastern University theorize that the Bernoulli principle—the same thing that lifts airplanes and hooks golf balls—may apply not just to objects in fluids like air, but objects sitting in a fluid-like flow, such as a beam of light.
The Bernoulli principle says that increased speed of a fluid decreases its pressure. On aircraft, air moving over the wing moves more quickly, creating low pressure, while air moving under the wing moves more slowly and thus has higher pressure, lifting the plane. In golf, a square hit creates backspin, which raises the pressure on the underside of the ball, holding it aloft. Sidespin causes the ball to turn. Tennis balls also rise and veer in response to the same forces, as do soccer balls.