One thing has gone unmentioned in all the eulogies for Professor Stephen Hawking, who died this week at the age of 76. Sure, he was a physics legend whose calculations forever changed how we view time, the universe and everything.

But he was also a hoopy frood who really knew where his towel was.

In other words, Hawking was a big fan of Douglas Adams' Hitchhiker's Guide to the Galaxy — the hilarious five-book "trilogy" and movie that began life as a BBC radio show. And there could be no more fitting tribute to his intergalactic greatness than for Hawking to become the voice of the all-knowing Guide itself.

That's what happened in the first episode of the sixth season of Hitchhiker's Guide, which debuted last Thursday on BBC Radio. Hawking voiced a new version of the Guide Mark II — the joke being that the electronic book's battery was so depleted, it only had enough computing power left to speak in the professor's famous 1980s retro-robot voice.

And in true brain-busting Hitchhiker's style, the show also implied that the Guide Mark II had spread itself throughout time and actually became Professor Stephen Hawking, rather than the other way around. "Others knew me in different forms," the Guide says. "I have been quite popular in my time. Some even read my books."

Here's the clip of the moment Hawking appears. To get the full insane context, here's what you need to know: the Guide Mark II previously appeared as a time-warping cybernetic bird that lured our heroes (Arthur Dent, Ford Prefect, Trillian, plus Arthur and Trillian's estranged daughter Random) to a version of Earth that is about to be blown up by an alien race called the Grebulons.

Now the Guide is holding the quartet in a virtual room outside time and space, in which it just simulated the next hundred years of their lives.

Hawking "was a huge fan of Hitchhiker’s and was keen to see the script," producer David Morley told the Radio Times. "He very quickly came back with a resounding yes."

But wait, there's more! On Monday the BBC broadcast an extended 45-minute version of the Hitchhiker's episode in question — in which we get the full scene Hawking recorded. (Pro tip: download it now, as the BBC will take it offline in less than a month.)

Just after the 30-minute mark, you can hear Hawking describe himself as a "pan-dimensional bio-hybrid organism." Hitchhiker's fans will note the similarity to the "hyper-intelligent pan-dimensional beings" who discovered that the answer to "Life, the Universe and Everything" was 42 — then built the Earth as a giant biological computer to work out what exactly the question was.

There may be no more fittingly nerdy fictional tribute to a man who spent his life leading the people of Earth towards a single "theory of everything" that could yet one day explain the entire cosmos.

Shine on, you pan-dimensional bio-hybrid organism.