The possibility of creating actual lightsabers inched closer to reality with the discovery that three light particles can be bound together, raising scientific and legal questions unseen since the Old Republic.
But unlike the crystal-powered plasma blades of “Star Wars,” news surfaced this month that a team of Harvard University and Massachusetts Institute of Technology scientists was able to bind photons by shining a laser through a cloud of rubidium, the metallic element below potassium on the periodic table.
The strength of three-photon bonds emerging from the cloud was very weak, but it’s a discovery that researchers believe can lead to further advances.
“We observed attraction between three photons, but it is not too much of a stretch to say that this could be scaled up in the future to many photons and make up a lightsaber,” said Aditya Venkatramani, a research assistant at Harvard University.
“In order for this to really be useful, we would need different lightsabers to repel each other,” Venkatramani said, something that can’t currently be done even with individual photons, historically considered massless.
The three-photon discovery was published this month in Science, a few years after the discovery of bonds between two photons.
So, could a laser sword ever be used by the public? Although they won’t be showing up on Christmas shelves this year, George Mason University law professor Joyce Malcolm said lightsabers almost certainly would be legal for civilians to possess under the Second Amendment once they’ve been perfected.
Unlike the Force-guiding limitations of a galaxy far, far away, Malcolm believes the only limitation to public use would be whether the weapons are found by courts to be in “common use” and for some “lawful purpose” such as self-defense, pointing to the Supreme Court standard in Heller v. District of Columbia.
Malcolm said lightsaber-control laws might stand initially, but courts ultimately would find a right to private possession. She points to rulings against a Massachusetts ban on stun guns, another weapon unavailable when the Bill of Rights was ratified in 1791.
As long as lightsaber use is deemed “close to the core value of protecting someone for self-defense, they would have a hard time banning” them, she said.
This would be the case “certainly if it had the sole purpose of something in legal use as a weapon … or some other lawful purpose, [though] I don’t know if you want to use it to kill a deer.”
Private ownership of grenades and machine guns is not protected by the Second Amendment because neither is in common use for a lawful purpose, Malcolm said. She sees lightsabers used for dueling and related tasks, however, as meeting the burden for protection.
There are, of course, people who doubt that lightsabers can be developed, much less mass-marketed, anytime soon.
Don Lincoln, a senior scientist at Fermi National Accelerator Laboratory and an adjunct professor of physics at the University of Notre Dame, points to the limited nature of the new findings.
According to the research paper, the bond between chlorine and sodium in table salt is 10 billion times stronger than the bond detected between photons. Lincoln said a hypothetical blade with so little binding energy could not slice through steel or villains such as Darth Maul. Merely swinging the blade would break the bond between photons, he said.
Lincoln noted the experiment was conducted at an extremely low temperature, limiting real-world applications, and said he believes photons bound to each other would not glow.
“The creation of solid light is a fascinating scientific advance, but unfortunately, it won’t lead to an elegant weapon for a more civilized age,” Lincoln said.
Still, Venkatramani believes future experimentation could show it’s possible to make a lightsaber, saying that replacing rubidium with sodium or potassium could increase the binding energy between photons, as could using a more powerful laser.
“It’s still an open question about how strong we can make it experimentally,” Venkatramani said.
