Back when "The Simpsons" was still good, celebrated theoretical physicist Stephen Hawking guest starred as himself in the season 10 episode, "They Saved Lisa's Brain." That 1999 appearance was the first of three guest roles on the show, and demonstrated what showrunner Al Jean described to The Hollywood Reporter as the late cosmologist's "tremendous sense of humor."

And while the appearance showed that Hawking didn't take himself too seriously, the writers on the show certainly did. Jean went on to explain how the esteemed physicist "was certainly a hero to all of us," and how the writers admired the work he'd done to "popularize science for people who may not have been interested in it," especially since they themselves had tried to do the same with their show.

And of all the writers in the history of "The Simpsons," none represented that passion for math and science more than David X. Cohen. The man behind such episodes as "Lisa the Vegetarian" and "The Itchy & Scratchy & Poochie Show," was a former physics major who was tapped by show creator Matt Groening to help develop the animated sci-fi sitcom "Futurama." That show debuted on Fox the same year that Hawking guest starred on "The Simpsons" for the first time and naturally, Cohen was keen to get the physicist on his new series, too. When he eventually did, Hawking was adamant that he wanted the full guest star experience.

Simpsons To Sci-Fi

After his guest role on "The Simpsons," Hawking spoke about how he enjoyed the jokes and being "depicted as a somewhat surreal character with enormous powers." Though his animated self is found hanging out with Homer at Moe's bar by the end of the episode, he's also not above punching Seymour Skinner with a boxing glove hidden in his chair, or declaring Lisa and her Mensa group's attempt at building a utopia, a "fruitopia."

When it came to "Futurama," head writer David X. Cohen played up the 'Stephen Hawking is actually a jerk' joke even more. The physicist, who passed away in 2018, appears in the season 2 episode "Anthology Of Interest I," which is comprised of three mini-stories, much like the "Treehouse of Horror" episodes of "The Simpsons." In the segment entitled "The Un-Freeze of a Lifetime," Fry (Billy West) asks Professor Farnsworth's what-if machine, 'What if I had never come to the future?' The machine then displays an alternate version of reality where Fry remains in the year 1999 and meets a team of nerds known as the Vice Presidential Action Rangers, guardians of the space-time continuum. The group was led by Al Gore, and included Star Trek's Nichelle Nichols, Dungeons & Dragons co-creator Gary Gygax, chess-playing computer Deep Blue, and Stephen Hawking.

Hawking would play a version of himself who doesn't think twice about having his goons beat Fry with tennis rackets, driving his wheelchair over Fry's face, or stealing other people's ideas and claiming them as his own. It's a hilarious subversion of the man's reputation as a thoughtful and respected intellectual that was well worth the effort Cohen and his team had to put in to record Hawking's lines.

'He Wants To Do It The Real Way'

David X. Cohen explained the logistics of recording guests in a Wired interview, where he said:

"With our regular cast we would try to actually get them in the same room, which is pretty unusual for a cartoon because I always thought the dialogue sounded more natural the more that we could have the characters, the actors really talking to each other in the studio. But with these guest stars it's usually impossible, they often don't live in Los Angeles or even in the United States in some cases."

When it came time for "Anthology Of Interest I," — I think, one of the best episodes of "Futurama" — Cohen had to fly to Al Gore's residence in Washington DC to record the Vice President in his secure compound. Hawking, however, was conveniently based at the California Institute of Technology in Pasadena, just outside of Los Angeles and it turned out the guest star wanted to actually have the guest star experience. With the "Futurama" production being based in LA, it proved to be a much easier task to record the Professor than it was to record Al Gore. As Cohen explained:

"We thought, 'Oh, maybe he can just email his dialogue since he uses an electronic voice anyway.' But he said no, he wants to do it the real way, he wants to have the experience of being a guest on the show, which I thought again was amazing and a cool thing to do. So we went to his house he was living in Pasadena, again brought the mics with us, and I got to meet him and talk to him there. Both as a science fiction guy and as a former physics major, that was certainly one of the highlights for me."

Pop Culture And Physics

Alongside his groundbreaking contributions to physics, Stephen Hawking made a real effort in his lifetime to publicize his passion for science and math. Not only did he leave behind an academic legacy, but a significant pop culture one, as well. And when you consider both "The Simpsons" and "Futurama" were, aside from being great comedy shows, basically deconstructions of pop culture, sprinkled with jokes about science and math, Hawking was really the perfect guest.

The man himself seemed to recognize his affinity with the two shows. Alongside his multiple "Simpsons" appearances, after his "Anthology Of Interest" cameo, he would appear as a head in a jar in the 2008 "Futurama" film, "The Beast with a Billion Backs" and the video game segment of season 6 episode "Reincarnation." According to Al Jean and the Hollywood Reporter, he would also, "tell jokes when he came to ['The Simpsons'] table reads, which he did several times."

Sadly, the upcoming "Futurama" revival will obviously not be able to feature Hawking in any significant way, but we'll be looking out for a background cameo at some point.

Read this next: Every Time Futurama Predicted The Future

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