Why did no one come to the party Stephen Hawking hosted on June 28, 2009?

Hawking threw a Champagne party for time travelers complete with Krug (champagne) and hors d’oeuvres in 2009, and didn’t release the invitations until after the party had taken place. If people had shown up, he hypothesized, it would be proof that time travel is real.

Hawking has been telling the story for a while now, explaining that “I have experimental evidence that time travel is not possible. I gave a party for time-travelers, but I didn’t send out the invitations until after the party. I sat there a long time, but no one came.”

Stephen Hawking (born January 8, 1942) is a British scientist, professor and author who has done groundbreaking work in physics and cosmology whose books have helped to make science accessible to everyone. Most recently he’s been focused on the fate of humanity and the role space and technology will play in our demise.

At age 21, while studying cosmology at the University of Cambridge, he was diagnosed with amyotrophic lateral sclerosis (ALS). Part of his life story was depicted in the 2014 film The Theory of Everything.