alain price : the lights are simply syncronised to each other with a timer that sends a signal to each light to change color.

yep, I've read a few of those but my limited understanding doesn't allow me to answer this specific problem.

As far as I can go (admittely, it ain't very far) when the centrifuge reaches light speed, both observers are travelling at light speed with respect to each other so they both should see the same thing; i.e own light normal, other getting faster. But this isn't what Mugaliens states...

Lets imagine that both observers can see each other directly. When at light speed (both observers are travelling at light speed with respect to each other), the observer inside the centrifuge should see the guy at the origin getting old very fast and vice-versa, right ?
When the centrifuge is stopped, they will both have aged the same amount or am I totally lost?

For those interested in the mechanical stuff, this is thought experiment only.