There are hobby sites, and then there are hobby sites where the safety equipment includes a blast shield because the coil around the quarter is expected to explode. Captured Lightning has been that kind of website since 1999.
Bert Hickman’s Stoneridge Engineering site is a sprawling archive of high-voltage experiments, Tesla coils, Lichtenberg figures, technical books, giant electrical arcs and electromagnetically shrunken coins. The site’s own slogan is “Wreaking Havoc with Electrons,” which is difficult to improve upon.
Hickman says he caught the Tesla-coil bug in 1995 after finding a Tesla-coiling area on a bulletin-board system. He was already trained as an electrical engineer, and after retiring in 2002 he devoted more time to Tesla coils, pulsed-power experiments and the branching electrical patterns known as Lichtenberg figures.
Making small change, very quickly
The Quarter Shrinker may be the site’s finest example of engineering performed partly because the result is funny. The machine uses high-velocity electromagnetic forming: a capacitor bank dumps a huge amount of energy through a coil surrounding a coin. The rapidly changing magnetic field forces the metal inward.
The site says a US quarter can be reduced to about the diameter of a dime at roughly 5,000 joules. The disposable work coil disintegrates during the event, producing exactly the sort of laboratory scene that explains why the site repeatedly tells visitors not to try this casually at home.
There are technical explanations, historical notes, galleries and even a reconstruction of how coin shrinking developed among experimenters.
Elsewhere, Hickman documents a 10-inch Tesla coil capable of long streamers, high-voltage arc photographs and acrylic Lichtenberg sculptures created by electrical discharges. The result is half engineering notebook, half museum and half mad-scientist gift shop. Yes, that is three halves. High voltage does things to the accounting.
A BBS hobby that became a permanent reference
This is exactly what the independent Web does well: one person’s unusual technical interest accumulates explanations, photographs, failure stories and specialist history until the site becomes difficult to replace. Captured Lightning was still receiving updates decades after it began.
It is one of the stranger engineering stops in CacheRat’s 1,967 Ancient Web Domains research list, which is full of projects that survived because somebody kept caring after normal people would have moved on.
Do not build the Quarter Shrinker because an article on the Internet made it sound fun. It is fun. That is not the same thing.
Explore Captured Lightning and the Nikola Tesla Information Center