I am constantly impressed by the imagination of people who dream up new sporting contests. For example, here is one event from the 2017 Marblelympics, where teams of marbles compete with each other. In this exciting event, the marbles travel on tracks that go underwater.
A calculation of solid spheres rolling (without slipping) down inclined planes shows that the speed at the bottom should be independent of the mass and radius of the marble. If the tracks and the release times are identical, then the times should be identical too.
I was curious about the variables that might lead to different times. Is it due to purely random minute fluctuations in conditions? There may be some slipping that occurs, especially when the marble hits the water barrier but I don’t know how one designs a marble to take advantage of that randomness .
But I appreciated the fact that the winning marbles acted sportingly and there was no taunting of the losers, no gloating, no chanting of “We’re number one!”, and no waving of flags. In dignified silence they took their positions on the winners’ podium.