Mathematicians seem to dedicate some attention to problems relating to the game of billiards (see Billiards, Dynamical billiars, Outer billiard). Has anyone been studying a somewhat similar set of problems relating to portals (as described, e.g., here), either in 3D or 2D? In particular, I’m inte...

So, I was playing this game called Portal Reloaded, which is basically Portal but with time travel added into the mix. I found it quite a conundrum to clear Chamber 07, and decided I should try to improve my understanding of solving it before I proceed forward. I was able to solve it, but I'm pre...

First of all, I'm not a mathematician, so sorry if the question is in layman terms. In the following picture, there is a character traveling toward the right. If the character encounters another character, he will always turn right (as a rule). There is also a time portal at the bottom, that will...