In Intro Physics we’ve started working on circuits using a modified version of the CASTLE materials and students encountered a question about which bulb in a two bulbs in series circuit would light first. This led to a lot of interesting conversations—some students swore they saw one lightbulb light before the other. Then one student suggested we try lengthening the wire and see if we could then tell which bulb lights first. Since this was another good chance to try out the high speed settings on my phone, I went ahead and created these two videos.
My colleague took this even further—he has his kids assume that the electrical activity in the wires was moving at near the speed of light, and then had them calculate how much wire you would need for there to be a 1/240 s difference in time.