Explore the dissolving boundary between science and science fiction with news from the front lines of discovery and imaginative speculation on how each one could change our world.
European scientists have developed lasers that can move particles with specially focused light. Before you get too excited at the prospect of a “tractor beam,” you should know that the beam currently works only on a microscopic scale. But don’t be disappointed, there’s still a lot this technology could do.
When a particle is irradiated with a specially shaped beam called a Bessel beam, the particle scatters photons forward. The recoil momentum these photons generate can overcome the force of incoming photons from the beam, moving the particle backwards. If that’s confusing to picture, imagine the particle is a balloon filled with air, and the Bessel beam is the gust from a fan. When the gust hits the balloon, it releases air (photons). If enough air is released, it can overcome the gust and move the balloon towards the fan instead of blowing it away.
Researchers in the UK and Czech Republic recently found that focusing a beam of light inwards generates the same effect as a Bessel beam. Using lasers, they were able to move tiny balls of polystyrene floating in water. They also observed “optical binding”, when the beam made particles stick together and arrange themselves into lines or structures.
So why can’t this technique be used to capture an enemy starship? All those photons bouncing around result in transfers of energy. This doesn’t mean much on a microscopic scale, but in a large object—like, say, the Millennium Falcon—it would cause massive heating and destroy the object.
Despite this limitation, the technology has many possibilities. Applications in the medical field could lead to advanced diagnostic techniques; one of the lead researchers suggested using the laser to separate white blood cells. It could also be used to assemble tiny robots. Just don’t plan on using it to drag spaceships back to your Death Star yet.
Okay, so this beam is not going to transport you onto the Starship Enterprise, but it’s still pretty cool. The medical possibilities are considerable. It might be able to target malignant cells and concentrate them for removal. Perhaps it could rapidly draw platelets to staunch a bleeding wound. Undoubtedly it could also serve the opposite purpose: instead of healing, the beam could misalign critical cells to cause internal, invisible harm. (Maybe it would be more effective as a ray gun than a tractor beam.)
It could also revolutionize the development of nanotechnology. The ability to arrange microscopic parts would allow for tinier and more sophisticated machines. Nanobots are a science fiction discussion unto themselves, so I won’t delve into the implications here, but this laser could drastically improve our ability to create such products. On a more pedestrian level, it would also enable us to make computer parts, medical devices, and other machinery smaller without sacrificing its complexity.