Again with a best-of post from the past, here's one from 3 Dec 2013.
Metro.co.uk - Stephen Hawking has invited time travellers to his birthday party in 2009. Apparently nobody showed up, so Hawking says this is conclusive proof that time travel is not possible.
I'm sorry, but there are alternate explanations.
#1: Ur doin it rong.
Assume time travel is invented in the 28th century. Well, of course no time travellers went to Stephen Hawking's 2009 birthday party! Time travel hadn't yet been invented in 2009! Therefore, in 2009, there is not one person in the world who has made the decision to travel back in time, so Hawking's birthday party is a bust.
Perhaps after time travel has been invented, we'll all of a sudden remember stories of how time travellers went to Stephen Hawking's birthday party in 2009. Suddenly we'll find an ancient photograph of Hawking's party, with him hanging out with John Titor, Captain Janeway, and Tom Baker.
#2: Y u so want time travellers?
I wouldn't invite time travellers to meet me if I were you. You never know: maybe your grandson becomes the next MegaHitler, so someone decides to go back in time and assassinate you to save the lives of billions. Maybe someone invents a superbomb capable of destroying the galaxy, and it's all because of some stupid equation that only Hawking could possibly have solved.
So if I were you, buddy, I'd just lay low. Quit being a fucking temporal heatscore.
#3: dude, ur teh lamez
If I were a time traveller, why the hell would I want to go back in time to visit Stephen Hawking? He's just some math dude in a wheelchair.
If I were going back in time, I'd want to go to Lindsay Lohan's Sweet 16 party. She was cute back then, and we now know she's crazy enough that I might get lucky.
In her pooper.
Sorry, Prof. Hawking, but there are all sorts of reasons time travellers may haven't have been wented to your birthday party. Some of them have to do with the weird time paradoxy stuff, but others simply reflect badly on you.