jewish_scientist wrote:What do you mean by information?
An (in my opinion) easier way to understand this is what isn't
Imagine you have a long chain of dominoes stood up But rather than doing it he normal way, you have them all set up to fall over based on a timer.
The timers can be set up to mimic a natural progression (let's say .1 seconds between dominoes), or faster, or have the whole chain fall at once, or even fall in reverse order (ie, A falling, then B falling onto A, then C falling onto B).
A natural chain of dominoes falling can send information, but the rigged setups can't. The rigged setups can superficially look like an initial tip over event spread extra-quick, but a careful examination shows the dominoes fell at their times because of the timers.
The laser pointer dot (Or a shadow) is a similar thing).
If a dot i at s=0 at t=0 and s=2 at t=1, that doesn't mean information traveled at a speed of 2, because the dot isn't where it is at t=1 because of where it was a t=0, but because somewhere else a photon was already on it's way to s=2.
The thing about recursion problems is that they tend to contain other recursion problems.