You can use information gleaned from the present that applies to the past’s future in general, but you can’t assume the past’s future will be the present. (Assume you brought a butterfly, and/or quantum randomness is redrawn.)
You can use information gleaned from the present that applies to the past’s future in general, but you can’t assume the past’s future will be the present. (Assume you brought a butterfly, and/or quantum randomness is redrawn.)