WHY THIS MATTERS IN BRIEF
Being able to move objects with light has been science fiction for a long time, but scientists in New York have already made it happen, and they’re now scaling it up.
Science fiction is rapidly becoming a reality, and we can see the evidence all around us – whether we’re 3D printing food, or human body parts, creating fully autonomous organisations and laser weapons, growing brains in jars, or just simply creating flying taxi’s or discussing the rights of robots. But in 1931, science fiction author E.E. Smith coined the term “Tractor beam” and the name stuck when it was used on Star Trek.
Now physicists at New York University (NYU) and NASA’s Goddard Space Center are turning fiction into reality and they’ve developed a tractor beam that uses a beam of energy, or light, to move objects in space. Although at this point it’s worth noting that it’s not actually space space it’s atomic space.
In 1997 the team at NYU created the world’s first set of “Holographic tweezers” to move small objects around, but now they’ve taken the process many steps further and they can now use a set of twin light beams to push, pull and move small objects around. Pulling though has proved more of a challenge than pushing but now the new technique can move small objects around at will, and that’s a breakthrough.
“It is like science fiction being made real. A lot of people will be familiar with the idea that a wave can push. It is possible to structure a wave so that it doesn’t just push, but it can grab onto an object, hold on to it, and even pull it. When we were first making tractor beams in the lab at first all we could do was move really tiny things over very, very small distances – just over a millionth of a meter. We are not lifting a battle cruiser and hauling it across space – But then once you have got to cm and to metres, the next step is km. That is what we are working towards now. In space exploration, this could be a very big deal,” said Dr. David Grier, physicist at New York University.
The process involves creating a hologram with both dark and light areas and the particles are drawn into the bright areas, and they can be dragged along both forward and backward by altering the hologram as the bright region move.
In addition, researchers have developed “Solenoid beams” that use a hologram beam but a spiral shaped one, and this beam of energy can attract particles depending on how the light is tilted and can move particles along its length.
Over time the researchers have gone from being able to move micrometer sized particles micrometers to being able to move them centimeters and now meters, and now they’re working on moving them over kilometers. So, as you can see, they have in fact created a tractor beam – and while it’s still decades away from being able to drag battleships out of the oceans it’s a start, and everything has to start somewhere. And don’t forget that Star Trek was set in the 2200’s so technically we’re light years ahead of where we should be and while the goal is to move objects over miles in space who knows, one day we could use it to get stuff from the kitchen – I’d buy that.
