[ExI] Great sf writers: A.A. Attanasio
pharos at gmail.com
Thu Sep 2 18:50:35 UTC 2021
On Thu, 2 Sept 2021 at 18:02, Adrian Tymes via extropy-chat
<extropy-chat at lists.extropy.org> wrote:
> But clearly it is not time travel. It just means it won't be seen at A - or its consequences (travelling no faster than light) affect A - for a few years. There may be an effect that might occur at A in a few years, and whoever teleported to and from B will have foreknowledge of this. (In this example, they might know to be on the far side of a planet from B when the radiation arrives, and when that will be.)
> "Time travel" would require going into the past of A itself, affecting things that were already perceived at A. (Or going into the future - call it A' - and then returning to the present, which would be going into the past of A'.) People can and do change the future without time travel (or FTL) all the time.
Causality violation needs to involve moving in different frames of reference.
(The maths is complicated).
This is a popular question. A search provides many confused responses. :)
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