Remix.run Logo
exe34 8 months ago

in some reference frames, yes.

wizzwizz4 8 months ago | parent | next [-]

No, not if we've observed it. There are predicted historical events which can be shunted into the future by running away bravely, but if you've seen them happen, you can only change how long ago.

exe34 8 months ago | parent [-]

not for us, but in some other reference frame.

wizzwizz4 8 months ago | parent [-]

If by "reference frame" you mean "observer who lives in the past", then yes: the past is sometimes the future of a more distant past.

exe34 8 months ago | parent [-]

no, relativity allows for reference frames where the event hasn't happened yet, even though it has happened for you. there's no simultaneous "it has already happened" for all frames.

wizzwizz4 8 months ago | parent [-]

There is if the event is in the past or future light cone. If A sends a signal to B, and B receives it, there is no reference frame where that signal went backwards in time. (Unless you count exotic ones, like "particle with imaginary rest mass is zooming along at thrice the speed of light", but you can't accelerate to such a reference frame so I don't.)

8 months ago | parent | prev [-]
[deleted]