High voltage without danger to life. On the trail of the little secrets of electrical discharge.
Not everything has been researched about lightning because it cannot be produced in a laboratory. And they are extreme phenomena, the magnitudes: 100,000,000 volts, 10,000 amperes, but only lasting a few milliseconds. Lightning is extremely imaginative in how it can carve out paths — and cause a lot of damage in the process.
There are large Van de Graaff generators that produce several 100 million volts. Interesting: What inspired ChatGPT to create the cover picture? Look at this historic machine, and you’ll see that the Westinghouse Atom Smasher inspired the AI image creation from the 1930s.
There’s a personal story about the experiment. In 2018, I did an experiment with an older Van de Graaf generator in the school’s inventory. High voltage with a candle. There were several interesting findings. One was that the candle apparently extinguished the spark. As soon as it comes close, there is no more discharge. My assumption was that the reason was the ionized air or the gaseous combustion products. They produce conductive areas in the air that allow the charge to run off with less resistance, i.e., without the effort of making an ion channel itself. But I would have liked to have positive proof of this.
This came five years later, a few days ago, when a new Van de Graaff generator became available. Secondly, we used a small candle. So the activated volume was smaller, and we could examine the process up-close.
And it actually succeeded: the spark makes its way from the electrode to earth via the candle. And it even takes a detour. It is, therefore, energetically worthwhile for the spark to cover the longer distance and part of the path within the area of the candle flame.
So, after years, I finally fulfilled the wish I had never forgotten.
A little-known physics experiment, not even in the inventory at schools. I would be very happy to receive a comment if you find anything about it.
Electricity in physics lessons can start with charge, electrostatic forces, and voltage. This can all be didactically prepared with high-voltage experiments. They are also — literally — exciting.
I created a YouTube short video on both the 2018 and the new experiment.
