Watch NASA and Portal's evil A.I. GLaDOS teach the difference between fusion and fission

Do you know the difference between fusion and fission? Some of us, sadly, do not. But once you've seen the NASA-produced video below, you'll know a little more about the nuclear reactions that power our sun and generate energy, respectively—with a little help from a videogame character who makes us laugh even as she's trying to kill us.

GLaDOS, the murderous yet uproariously funny A.I., comes from the 2007 videogame Portal and its 2011 sequel, Portal 2. These games had increasingly intricate puzzles involving a gun that opens portals, as well as dialogue like "That thing is probably some kind of raw sewage container. Go ahead and rub your face all over it."

It's wonderful to see GLaDOS (again voiced by the sensational Ellen McLain) teach two orange-jump-suited techies about nuclear physics, because we get to learn while we're fearing for their lives.

There may also be a lesson or two about trust.

At least we know that GLaDOS likes to teach science, for science. You monster.

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