This video is a bit of a teaser posted as part of the #VeritasiumContest, which requires videos be no longer than one minute, and also as part of the #SoME1 contest. Obviously, I can't go into much detail in a one-minute video, but I will be posting a follow-up video that contains much more detail about a rolling wheel. For such a simple system, there's a surprising amount of subtle physics at play. So if you hunger for a more detailed explanation, check back soon (better yet, hit the subscribe button).