There was once a question put to the issue of time travel.
If time travel is possible then why is it we havent been visited by time travel tourist?
The answer given was..”How do we know we havent?”
I tend to believe that there is other life as the universe is so large that in no way can we determine there isnt other life out there. But what kind? If intelligent, then are they friendly or aggressive? Do we want to “welcome” them if they show up? Would we know for a fact that they are friendly? And what defense would we have since they are so far advanced if they decide to simply take over?
I think they come here to steal guitar licks.