From The Archives: Stephen Hawking Playing Poker With Einstein, Newton And Data In "Star Trek"

From an 1993 episode of Star Trek: The Next Generation, in which the late physicist Stephen Hawking made an appearance, playing himself, at a game of poker he played with Data, Sir Isaac Newton and Albert Einstein:

      

A little backstory about Professor Hawking's appearance in Star Trek, from Wikipedia:

At a screening for the 1991 documentary film A Brief History of Time, which was based on the book of the same name by British theoretical physicist Stephen Hawking, Hawking was introduced to the audience by veteran Trek actor Leonard Nimoy. A Brief History executive producer Gordon Freedman told Nimoy that Hawking was an avid Star Trek fan. This led to an arranged visit by Hawking of the set of Star Trek: The Next Generation, which included an opportunity by Hawking to sit in the captain's chair. Freedman told the show's executive producer, Rick Berman, that Hawking would appear on the show if asked. Hawking accepted the ensuing offer, marking the first time a guest star played himself on an episode of any Star Trek series. After he was sent the script, he made some modifications to it, including improving a humorous line of dialogue to make it funnier, which Berman called "delightful".

[via]