Re: how can you get shocked without a path to ground ?

Dear cool,

Thank you for your question. Without knowing how this contraption works, I cannot say with certainty what the physics behind the squirrel's reaction is. I have, however, two theories that could explain what can be seen in the movie.

My first idea is that the rod the squirrel touches is in fact not a solid rod, but rather somehow contains two conductors that have a high voltage between them. The squirrel then touches both conductors at the same time, gets a shock, and runs. This idea is based on the following three things:

• It is by far the easiest way of achieving this effect.
• There are two wires attached to the pole; if a solution that uses a high-frequency field were used, it would be more natural to simply ground one wire.
• Based on the way the pole looks when it swings, it does not look solid.

The second idea I had is that the rod is solid, and that there indeed is no conductive path to the ground. In this case, it is still possible to create a voltage difference if the frequency is high enough. Essentially, the squirrel's body acts as a capacitor. If it touches the pole, its body gets rapidly charged and discharged. What makes this theory weak is that the capacitance of something as small as a squirrel's body is quite small. Nonetheless, with (sufficiently) high frequencies, capacitive coupling can be quite effective.

At this point, this is all I can do for you. I have mailed the contraption's builder, but have had no response up to this point. As such, all we can do is speculate, as there are multiple ways in which this device could work.

Regards,

Bart Broks

*** Update ***
I recently received an email from the person who built the device. Turns out my guess was correct, it does use two conductive strips. The high frequeny might work, but it is inefficient, as it will continuously "leak" energy.