Whenever someone invents time travel, it starts modifying the timeline, and it does not become stable again until the discovery of time travel is prevented from happening. The exception is if some of the futures that would modify the past cease to exist. Therefore, time travel is only possible when the survival of the universe itself is at stake.
That’s my movie idea, anyway.
Bingo! Thank you. Now I need to find a copy.
Somebody needs to edit the Wikipedia page of time travel stories cause it ain’t on there!
That’s the first place I checked!
I was looking for this a couple of years ago.
After a month or so, some kind bod on Reddit got me there.
I did that tomorrow
I’ve really been thinking on this one, and if I had a time machine I’d want to go back in time to see the Pyramids of Giza when they were freshly finished, but also to see what the area looked like before they were there, too.
I’d want to go visit Mount Rushmore before it got it defaced (or I guess, ‘faced’), see Mount St. Helens before the eruption. Go to Crater Lake when the basin was newly formed but hadn’t yet filled with water. It’d be cool to experience Krakatoa’s eruption, too!
If I had a time machine, I’d go back and do this day over.
Me too.
The solution to that is obvious!
Even in Baseball, but not as cosmic… except for the more rabid fans watching the ballgame. Follow me here. Scenario: There’s a man on 2nd base… call him Batter 1. Batter 1 gets reckless and gets picked off — OUT! Fans get pissed. Then the next batter, call him Batter 2, gets an extra base hit that would have scored Batter 1 had he not been picked off, scream the angry Fans. Wrong. With Batter 1 still on 2nd base (not picked off), the pitcher – being aware of Batter 1 on 2nd base and what problems that posed for any pitcher – would have selected different pitches to Batter 2, so the pitches thrown to that batter would have likely varied by the pitch types and order selected by the pitcher and catcher, so the conditions that led to Batter 2’s hit would have changed. Batter 1, by being picked off, changed pretty much everything… given the unpredictability of Baseball, the so-called game of inches.
I’m a fan but even I had to laugh! 
Yes, that’s The Man Who Folded Himself by David Gerold.
Which is only fair since he spent a good part of the novel hooking up with himself anyway.
Gah! That’ll teach me to not read the rest of the thread first. 
TBF: At least you added a link.
I checked our library catalog first, but there are no copies available in our consortium. With the power of almost 50 libraries at our disposal, that’s kind of rare! Goodreads is my fall back in those cases.
