Courses: P4, P14, P16, P41
A vertical transformer which launches a copper ring into the air. The ring will jump nicely at room temperature, and shoot very high if first cooled in liquid nitrogen. It's possible to hit the ceiling in 104 and 111 when using LN2 -- be cognizant of where it is aimed. It is also possible to tilt the unit so that it flies down an aisle into the audience. Before doing this make sure to give someone cryogenic gloves with which to catch the ring.
This demo is very likely to trip a circuit breaker, and will not work if connected to a GFCI protected outlet. As the college locks down circuit breaker boxes it may be necessary to bring someone with keys from FO&M or Safety and Security, to be on hand to reset the breaker between trials. I generally run an extension cord to one of the outlets in the demo prep area, since the protected A/V outlets in the classrooms are not up to the task.
The switch must be clamped to the bench using a c-clamp, so it can be quickly switched on and off without having to hold it still. Use a piece of wood on top of the switch to avoid cracking the plastic.
Safety: Even though Yorke doesn't use any in the video, please do put out cryogenic gloves and splash goggles for protection from the LN2 and from the chilled ring when catching it!