Neil deGrasse Tyson is not one to back down from a debate and he's very adept at setting people straight. In an episode of "StarTalk" however, he had to sit back as Brian Cox talked about the physics of lightsabers, correcting him.

This conversation, however, started back in 2013 when Tyson posted on Twitter that lightsabers are useless for defense because the "blades" are made of light, meaning they would simply pass through other objects.

To this, Cox, a physicist, responded that lightsabers may have defensive capabilities if their photons have enough high energy. This would result in cross sections large enough, allowing for blocks.

The Twitter exchange went on for a while, with others giving their two cents as well about the topic. 

One Twitter user even called Tyson and Cox the modern-day equivalent of Da Vinci and Michelangelo.

Still, that conversation about lightsabers did not have a proper end. Did Tyson concede? Was Cox able to make his point?

It wasn't until Tyson and Cox sat down together for "StarTalk" that the two were able to clear up their positions.

"There's a process I've studied ... gamma-gamma scattering we call it ... a measured process at particle accelerators ... so at very high energies, very high-energy collisions, there's a probability that photons will kick off each other, bounce off each other," said Cox.

According to the physicist, it's a remarkable property of particle physics that photons are all over the place but don't interact, ensuring that they don't mess up your view. However, the probability that photons will collide increases as the level of energy increases.

"It would have to be [a] really, really high energy lightsaber ... and they would come in contact and you would feel this [interaction]," said Tyson.

Aside from the two agreeing that the probability exists that photons will interact with each other, meaning lightsabers can indeed be a reality, they also took some time to gush over people geeking out over their Twitter conversation version.

"[I] appreciated how much people would geek out over that," ended Tyson.

Watch their little face-to-face exchange below!