The Boston Museum of Science is world-famous for its engaging exhibits and informative displays. Their lightning exhibit alone has drawn thousands and thousands of visitors (like me). What makes it so special is that they built and operate the largest Faraday cage in the world there.
A Faraday cage is an insulated (metal) cage that lets someone experience a lightning storm up close. In theory. In practice, cars for example, are built to protect the people within them from possible hits of lightning. The car itself can and will most likely be totalled, however the passengers take minimal to no damage from an otherwise deadly voltage.
Purpose-built faraday cages are completely safe and used in physics experiments as well as, in the Boston Science Museum, to show the beauty that is hidden in the destructive force of electricity. These fake lightning storms are generated by a so-called Van der Graaff generator. This is a spark generator that creates lightning like surges of electricity.
The whole thing is air-insulated to contain the phenomenon within. It is part of the normal museum building and can be visited via a special show, in which visitors get to first-hand experience this. As for the machine itself, it looks like a metal ball on a long stick when shut off. In fact, most of us have already seen one.
They were very popular in the 90s and 2000s as Plasma globes. Those little, often USB powered, looked like empty plastic balls with a metal ball in the middle. Kids all over the world loved them as they would generate purple sparks of electricity that would dance on the inside of the plastic (or glass) container. When touched by human fingers, the electricity would move there.
These plasma balls aren’t quite the same thing, however as a comparison they work well as the process is the same-comparably large amounts of electricity are discharged as little purple bolts. In clear skies (which are somewhat rare during lightning storms) the bolts will also appear somewhat lilac or purple, or white. On very rare occasions it can even appear as blue. This depends on a variety of factors such as location, time of day, and strength of electricity. The bolts in plasma balls are always purple however.
I don’t know a single child in my school that didn’t have-or wanted-one of these. On a much (much, much) larger scale, the Boston Museum of Science’s Van der Graaff does the same thing-except during the show, the visitors are IN the ball, and not touching it from the outside. In fact, the chamber at the centre is where the electric bolts end, due to the Faraday cage. Tesla coils are also used to generate up to 2 million volts.
In comparison, a natural stroke of lightning has much less-less than half at maximum strength and a fraction of it for the average lightning storm. Unprotected, this is still more than enough to kill a human hit by it (though there are the occasional survivors). In comparison to this very dangerous phenomenon, the museum show is completely safe.
It is, also, an amazing spectacle. A guide explains what’s happening during the show which takes place several times a day. In addition to the general lightning show, there are also features for children, such as the static-generator responsible for a plethora of funny pictures. The static electricity generated will make the hair of the person touching it stand on end-very popular with young boys, not so popular with teenage girls surprised by the effect.