Scientists from the California Institute of Technology (Caltech) have discovered a way to propel an object using only light. The implications of the research could be huge as it could potentially allow a spacecraft to reach planets outside the solar system in just 20 years – a huge decrease on the millions of years which had been proposed. Caltech researchers designed the so-called “photonic levitation and propulsion” system using nanoscale patterns of light to move much larger objects.
A piece of paper is about 100,000 nanometres thick.
Their theoretical device works by using “optical tweezers” which fire powerful lasers which can attract and push away objects.
The laser is then reflected on an etching on the object which allows it to “self-stabilise”.
Lead researcher Dr Ognjen Ilic put it simply: “One can levitate a ping pong ball using a steady stream of air from a hair dryer.
“But it wouldn’t work if the ping pong ball were too big, or if it were too far away from the hair dryer, and so on.”
For now, the research is purely theoretical but the scientists behind the study say in the future, the laser beam could be billions of miles away, which could be the future of intergalactic space travel.
As the spacecraft would not need to carry any fuel, it would be able to travel at close to the speed of light, allowing experts to explore distant planets.
Professor Harry Atwater, who is also the director of the Joint Center for Artificial Photosynthesis, said: “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.”
All potential spacecrafts are likely to be unmanned, however, according to the research published in the journal Nature Photonics.