[ExI] Great sf writers: A.A. Attanasio

[BillK]

On Thu, 2 Sept 2021 at 18:02, Adrian Tymes via extropy-chat
<extropy-chat at lists.extropy.org> wrote:
>
<snip>
> 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).
See:
<https://physics.stackexchange.com/questions/52249/how-does-faster-than-light-travel-violate-causality#54242>
This is a popular question. A search provides many confused responses.    :)

BillK