Serial debunker of movies and TV Neil deGrasse Tyson took on Game of Thrones on Sunday evening, analyzing everything from the chains the army of the dead used to pull up dead dragon Viserion (wrong angle) to the dragons themselves (good wing span, though experts we spoke with say they're still too heavy to fly). And then he dropped an intriguing tweet that just might explain Ice Viserion's blue fire, which easily cut through the Wall:

Inverse's Yasmin Tayag took a deep dive into the physics of dragon fire after the season finale and concluded that, according to science, blue flames are the hottest of them all. Typical Game of Thrones dragon fire—the red, yellow, and orange kind—is the result of incomplete combustion. The color is caused by the fuel in the dragon's gut (likely carbon) releasing chemicals as gas in a process known as pyrolysis. Blue flames, though, mean complete combustion, which, according to Tayag, "can only occur when there’s plenty of oxygen available to allow a flame to get super hot, and the fuel being burned doesn’t release too many additional chemicals during pyrolysis that might lead to a different colored flame."

In August, Game of Thrones sound designer Paula Fairfield—perhaps in an attempt to answer viewers’ nagging question about whether Viserion was blowing fire or ice—told Vanity Fair’s Joanna Robinson that, “He’s just going at it and slicing with this. It's kind of like liquid nitrogen. It’s so, so cold. So imagine if that’s what it was, but it’s so cold it’s hot. That kind of thing.”

This could have big consequences if Ice Viserion and Drogon face off. "If the HBO series decides to follow these particular laws of thermal physics (and why should it when Thrones so flagrantly disregarded chain physics?!?), then Viserion will surely be at an advantage if and when he ever goes talon-to-talon with his brother Drogon," wrote Robinson in response to deGrasse Tyson’s tweet.

Game of Thrones's final season won't debut until late 2018 or 2019, so we have a long time to wait before we see which dragon's fire comes out on top. 

[h/t: Vanity Fair]