Intrinsic wrote:Yeah yeah .... but jes conjecture on yer part. i know about cause and effect are relative to the observer, ie the receiving is the cause and effect is sending. It was Feeman?? proposed it, i think it was freeman ... i'll look it up later ... this is outside the QT effect...

whups ... i meant Richard Feynman ..

https://en.wikipedia.org/wiki/Wheeler–Feynman_absorber_theory

"T-symmetry and causality

The requirement of time-reversal symmetry, in general, is difficult to conjugate with the principle of causality. Maxwell's equations and the equations for electromagnetic waves have, in general, two possible solutions: a retarded (delayed) solution and an advanced one. Accordingly, any charged particle generates waves, say at time {\displaystyle t_{0}=0} and point {\displaystyle x_{0}=0} , which will arrive at point {\displaystyle x_{1}} at the instant {\displaystyle t_{1}=x_{1}/c} (here {\displaystyle c} is the speed of light), after the emission (retarded solution), and other waves, which will arrive at the same place at the instant {\displaystyle t_{2}=-x_{1}/c} , before the emission (advanced solution). The latter, however, violates the causality principle: advanced waves could be detected before their emission. Thus the advanced solutions are usually discarded in the interpretation of electromagnetic waves. In the absorber theory, instead charged particles are considered as both emitters and absorbers, and the emission process is connected with the absorption process as follows: Both the retarded waves from emitter to absorber and the advanced waves from absorber to emitter are considered. The sum of the two, however, results in causal waves, although the anti-causal (advanced) solutions are not discarded a priori.

Feynman and Wheeler obtained this result in a very simple and elegant way. They considered all the charged particles (emitters) present in our universe and assumed all of them to generate time-reversal symmetric waves. The resulting field is"

Desolves into the math ...

Since interstellar distances involves more then change in Location, but time changes too, (remember time does not advance in low orbitsame as on the earth's surface). And no one knows for sure how time changes in interstellar space far from mass.

It may be possible the only way to commutate over such vast distances in space thus vast distance in time is to receive the message before (relative to the sender) it is sent. Feymnman/Wheeler above shows why it is possible.

SETI assumes a contentious one direction linear flow in time, if even variable. But it is all we can do for now.