Harvard and MIT Researchers Invented ‘Lightsaber’ Technology … Sort of

The team manipulated light so that it would act like molecules.

A research team led by Harvard and MIT physics professors has manipulated photons of light to form molecules, a discovery that is very exciting to people with a high level understanding of physics … Of the discovery, Harvard Physics Professor Mikhail Lukin says, “It’s not an in-apt analogy to compare this to lightsabers.”

Ok, now the rest of us are listening.

“When these photons interact with each other,” Lukin says, “they’re pushing against and deflect each other. The physics of what’s happening in these molecules is similar to what we see in the movies.”

Lukin must know that there’s no better way to interest us in your complex scientific discovery than to draw an metaphor to a sci-fi film from the 1970s. But sadly, their discovery, published in the journal Nature this week, does not actually make it possible for us to wield sword hilts with laser beams that bang against each other and slay jedis.

Here’s what they actually did:  In normal circumstances, light is massless. It doesn’t interact with other light. When you intersect two laser beams, they just pass through each other. But the researchers, led by Lukin and MIT Professor of Physics Vladan Vuletic, placed rubidium atoms in a vacuum chamber, then chilled them to nearly absolute zero (which, Walter White reminds you, is different from regular zero. It’s -273 celsius, to be exact.) Then they fired a group of photons into the atom cloud, finding that they exited bound together like a molecule. This is, apparently, a very big first.

“Most of the properties of light we know about originate from the fact that photons are massless, and that they do not interact with each other,” Lukin says in media reports. “What we have done is create a special type of medium in which photons interact with each other so strongly that they begin to act as though they have mass, and they bind together to form molecules. This type of photonic bound state has been discussed theoretically for quite a while, but until now it hadn’t been observed.”

“We do this for fun, and because we’re pushing the frontiers of science,” Lukin said. But they have some real world applications, too, because for instance you need something with which to duel a Sith lord “photons remain the best possible means to carry quantum information. The handicap, though, has been that photons don’t interact with each other,” Lukin says. Huh? So can we expect to buy these lightsabers by Christmas or what?

Eric Randall
Eric Randall Eric Randall, Contributor at Boston Magazine ericrandall988@gmail.com