This summer, Japan's golden solar sail unfurled in space, becoming the first successful mission to sail on the physical pressure of the sun's radiation. Its success led dreamers like Planetary Society director Bill Nye to envision a future of machines pushed forward by the pressure of lasers to explore the cosmos. And now, down here on Earth, researchers say they have demonstrated one of the key principles needed to realize such a vision: a "lightfoil" that uses light to create lift. The lightfoil described in Nature Photonics is only micrometers in scale, but lead researcher Grover Swartzlander argues that it shows scientists can create and control optical lift. It operates on the property of refraction--how glass bends light.
Optical lift is different from the aerodynamic lift created by an airfoil. A plane flies because air flowing more slowly under its wing exerts more pressure than the faster-moving air flowing above. ...
