So, my source for memes posted an interesting thought experiment. It’s surprisingly thought-provoking and hard to answer.
You have a time machine. Where/when would you go under each of the following circumstances?
For leisure or entertainment:
I think the future would be fun; but that’s about all I can tell you.
To change history:
Toying with the past — even discussing contrafactuals — has unintended consequences. Naturally, I would be tempted to intervene and prevent some of the great recent tragedies: genocide, fascism, political violence, terrorism. But would all this hasta la vista, baby really work?
I think it would be more productive to nudge the world along in the direction it has been going for millenia. But if I could do anything it would be to prevent or moderate colonialism from the 1400s onward. Six hundred-odd years of wasted talent, misappropriation, misunderstanding, and mistrust . . . We (all of us) will be lucky to untangle it in half that time.
To meet someone and hang out with him or her for an entire day:
I dunno. The emporer Diocletian? Nah. Maybe Genhis Khan. Yeah. Or Merriwether Lewis. Definitely! Genghis Khan or Meriwether Lewis.
To be mischevious:
I think it would be mighty fun to play the Ghosts of Christmases Past, Present, and Future with several recent American presidents.
To witness a particular event:

