The Big Bang Theory

The Celebration Experimentation

Series 9 - Episode 17 The Celebration Experimentation

Today 11:35pm - 12am E4
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Sunday, 3:20am - 3:45am E4


It’s Sheldon’s birthday and we learn why the occasion fills him with dread: he was bullied as a child and Batman never turned up to his party, as was once promised.

Under gentle pressure from his girlfriend Amy, Sheldon concedes to “cake, presents and a shower of admiration and love”. And the boys plan to right a few wrongs by inviting 60s TV Caped Crusader Adam West to the festivities. Cue some nicely nerdy “best Batman” banter.

From the off, The Celebration Experimentation is one enormous smile. All the gags work, there are a few surprise cameos (the guest of honour is very guessable to longtime fans) and plenty of pretty speeches – plus one of those thrilling little Penny-and-Sheldon moments the writers have such fun with. The story is not only a tribute to its lead character but to the show itself, now 200 episodes to the good. Fittingly, it’s celebratory, snappy and sweet.


In the 200th episode of the comedy, the gang finally celebrates Sheldon's birthday after more than nine years together, with the help of a few special guests. Starring Johnny Galecki, Jim Parsons and Kaley Cuoco, with guest appearances from Adam West, Wil Wheaton and Stephen Hawking.

Cast & Crew

Leonard Hofstadter Johnny Galecki
Sheldon Cooper Jim Parsons
Howard Wolowitz Simon Helberg
Raj Koothrappali Kunal Nayyar
Penny Kaley Cuoco