Tim Bradshaw wrote:
> Neither my maths nor physics is now up to working out how toxic
> causality violating solutions are, but I still have this really bad
> feeling about them.
Most of our science is based on causality, i.e. the principle that the
cause of a phenonmenon is before the effect. SR restricts causality
further to limit the propagation of any cause to light speed (because
otherwise we can find at least one inertial system which observes
Abandoning causality is breaking the complete structure of science
(except math), because it's one of the fundamental axioms. However,
causality also does require that the universe isn't deterministic, since
a deterministic universe is just like a 4 dimensional fractal, where
complete knowledge of one position is sufficient to deduce all others
("Laplace deamon"), those of the past, and those of the future.
There are two ways out of that: either we (from the inside) just can't
obtain complete knowledge, or it's really random. From our point of
view, it's the same (we can't tell the difference), from the point of a
supervisor "observing" the universe outside time and space, it's the
same, too, since she can create a deterministic universe by just
recording what happens - the recorded copy acts the same as our
universe, although it is completely deterministic. Just like a random
generator either could use a large seed at the beginning, or take random
events from outside while operating: as long as the total number bits
introduced from the outside are the same, you can't tell the difference.
The other option to have a sort of causality as well as determinism is a
"Alzheimer universe", thus the past can't be deduced out of the current
state. Since it doesn't matter whether you take time as going forward or
backward (although a few formulas change when time runs backward), the
Alzheimer universe is just the same as our universe, only with negative
time. In other words: what is determined we call the past, what is
unknown we call the future.
The wonderful thing about QM is that it explains why we can't obtain
complete knowledge - the uncertency relation prevents it. It furthermore
shows that all simple hidden state theories (which would allow to
discover the hidden value) don't work - the current experiments don't
close all loopholes for hidden state theories, but those that remain
don't reveal their states (and therefore violate Bell's inequation).
"If you want it done right, you have to do it yourself"