Time travel and the music of heavy metal band Wyld Stallyns is the basis for all civilization.
Time travel is possible, but only forward. Or so I think. But I don’t really even know what time is, so I shouldn’t say that. But it seems unlikely.
Some say time travel is impossible because of entropy. Others say that if it was possible, we would have been visited. Others point out the paradoxes involved.
The Wyld Stallyns part? Pretty likely, however.