On 28 June 2009, as a tongue-in-cheek test of his 1992 conjecture that travel into the past is effectively impossible, Stephen Hawking held a party open to all, complete with hors d'oeuvres and iced champagne, but only publicized the party after it was over so that only time-travellers would know to attend; as expected, nobody showed up to the party.
That's brilliant.
Yet they have not shown up yet. When does the past appear is the real item here.
We will continue to study time travel and I , personally, believe we can go back, after all , the only way to go back is to have a memory enabling you to identify the event. With this it is assumed that we are the only one to confirm the past with our self. If I arrive at the party, I was already there
Ok... they didn't show up because they knew it was a catch 22....lol!