I thought it was interesting when he took apart the gyro and messed with it's friction ability and then gyro could no longer spin.
In figure skating, when a skater prepares for a spin, the skater takes a wide inside back edge with a slight crossover maneuver (crossover at the millisecond point of entering the spin-going backwards usually) before the intended leg reaches into the beginning part of the spin. Usually the left leg for a right handed skater becomes stationary and centered. In order for the spin to work effectively, (here's the physics; you chose the nerd factor ), during the moment the skater swings into the spin, for an upright crossover spin, the skater goes from open arms to bringing in the arms tightly to the chest (or overhead). The faster the arms are brought in, the faster the spin. This then increases the spinning speed exponentially, when the skater's spin is stable and centered (traveling- which means, the skaters spin is not centered and is "traveling" away from the origin of the spin and skater is actually moving inches in another direction; points off for traveling a novice no-no) to finalize the spin, the skater would cross over one boot over the spinning boot and voila....you have a crossover spin. Here's another physics part ~ if while the skater is spinning and the skater changes positions, which during competition skaters have requirements to meet to complete several different spin types during the same spin session ( e.g. lay-back, broken-leg, camel, sit-spin etc.), when the skater breaks the momentum of one spin and goes to the other, watch the arm movement. The arms open and change the direction and spin speed slightly before resuming the new position for the spin and the momentum begins over again while the skater is in a different spinning position. The physics in jumps is also interesting on how you have to gain upward momentum while engaging in a air-spin (spin cycle physics in jumps are the same as arms are brought in tightly and that also determines how many spin revolutions a skater can accomplish. *Secret to great jumps is in the edge preparation before the leap.