The butterfly reference comes from the science fiction short story ‘A Sound of Thunder’ by Ray Bradbury.
A time traveler goes back to the days of dinosaurs to hunt extinct species... Killing dinosaurs doesn’t change the future, but while doing so one of the hunters steps on a butterfly and does change the future.
Not everybody who is alive today is here because the allies defeated Japan with atomic weapons. But because atomic and nuclear weapons were created, humanity will eventually be destroyed and that will be because Physicist invented them. Some lunatic in the future will use them. You can’t dis-invent the wheel. We have the tech to destroy our own species and that technology will be used.
That is an inevitability and you don’t need a time machine to figure that out.
“science fiction”
We were discussion non-fiction.
“Not everybody who is alive today is here because the allies defeated Japan with atomic weapons.”
Correct. Just last Sunday I met a man that was born in 1943.