NASA has teamed up with GLaDOS to explain the difference between fusion and fission, neither of which the notorious AI would ever dream of using to impose her vision of machine utopia on the planet.
Fusion. Fission. Do you know the difference? I don't. I know that both have roles to play in apocalyptic nuclear kablooie, but beyond that, well, let's just say that science was never really my thing.
But rogue AI temptresses? That's most definitely my thing, and so it is that I actually paid attention to this brief science lesson taught by none other than GLaDOS, the notorious and slightly imbalanced machine intelligence that made Portal so interesting. Through a strange twist of fate, GLaDOS finds itself (herself?) being installed at NASA, giving her (it?) an opportunity to demonstrate its utter benevolence, harmlessness and total lack of evil intent. GLaDOS loves you.
The video was produced by the education and public outreach department of NASA's Spitzer Space Telescope, part of the Jet Propulsion Laboratory in Pasadena. Valve doesn't appear to have been involved in the production, although it does get a note of thanks in the credits, and the voice actor is in fact Ellen McLain, the "real" GLaDOS.
It's a little bit cheesy in spots, as educational materials almost inevitably are, but McLain is dead-on and the computer techs are doing their best. There are a few genuinely laugh-out-loud moments, too, and most important of all it presents real science in an accessible and entertaining manner. I'd call that a win.
Source: Spitzer Space Telescope