Scientists at Caltech found a way to levitate and propel objects using only light. They hope the technique could be used for “trajectory control of ultra-light spacecraft and even laser-propelled light sails for space exploration,” according to a paper published in the journal Nature Photonics Monday.
Physicists have previously used optical tweezers, fine-tuned laser beams, to trap and manipulate nanoparticles. Researchers have also used light to power tiny motors. However, optical tweezers are limited by distance and the size of the objects. Essentially, only very small objects can be manipulated with light in this fashion and only from close range.
The method is not limited by an object’s size or distance from the source, which means macroscopic objects such a spacecraft could be accelerated, perhaps even close to relativistic speeds, using the force of light alone.
“There is an audaciously interesting application to use this technique as a means for propulsion of a new generation of spacecraft. We’re a long way from actually doing that, but we are in the process of testing out the principles, Atwater, Director Joint Center for Artificial Photosynthesis, said.”