Is there a scientific reason for what happens in this vedioVYuSt9FSccE

If you actually watched it, right in the video it tells you he has written the explanation for it. Just looking quickly. I was able to find the scientific reasons behind this... right there where he posted the video on Youtube.

"Luckily, physics comes to the rescue, since there's a so-called "conservation law of angular momentum". The cork/string part will act as a pendulum, but the cork will gain speed as the string is pulled by the cup (smaller radius means greater velocity; it's the effect ice skaters use when performing a pirouette). The cork is then flung around the PVC tube a couple of times. The string creates friction on the tube, thereby slowing down the cup as it almost hits the ground."