Theoretical physicist Stephen Hawking passed away yesterday at the old age of 76. In fact, Stephen Hawking's whole life from birth until death was as many people put it a sign of the cosmos themselves. Hawking was born January 8, 1942, on the 300th anniversary of Galileo's death and died on March 14, 2018, the same date of Albert Einstien's birth.
Strange, we know, but there are even stranger things accomplished (or not) by the notable scientist. Hawking once held a party for time travelers, yes, time travelers, hopefull that he would either prove or disprove the possibilities of time travel Hawking put on a party, but sadly, no one showed up.
However, unlike a normal party, where guests are invited with timely and addressed invitations, Hawking purposefully did not send out his invites prior to the event. Instead, he thought, that if he sent them out after the fact, and left the detailed invitations in secure places where future people would find them, to him would prove the abilities of time travel.
The idea rests on the basis that if time travel was real, it wouldn't matter if the invitations 'arrived' on time. But that a future civilization would be able to manipulate time in a way as to make the party, even though they are hundreds or even thousands of years late. The provided coordinates time and date would be enough for these time travelers.
Now, if you're a fan of science fiction and even theoretical puzzles, one may suppose that in this timeline the party has yet to happen, that possibly, in another universe Hawking's party was in fact visited by time travelers, but here and now, it just hasn't happened yet.