Tesla Coils, Concrete Crushing, and Asteroid Impacts

The entire universe in blog form
March 31 2013 8:00 AM

Crushing and Zapping and Impacting at the University of Illinois

Tesla coils
Tesla coils, thankfully, cannot scream, "Exterminate!"

Image credit: Phil Plait

[UPDATE (April 13, 1845 UTC): The concrete crusher video below went viral recently, getting picked up by Digg, Gizmodo, and Laughing Squid. Cool!]

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

In early March I was at the University of Illinois Urbana-Champaign to give my “Death from the Skies!” talk about asteroid impacts. As you might imagine, I had some new, rather state-of-the-art things to talk about.

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The talk was the keynote for the Engineering Open House run by the UIUC Engineering department every year. I wasn’t sure what to expect when I got there, but the EOH is a big deal: thousands of people of all ages from around the state come to attend the festival. It was really big, and a lot of fun.

My chaperone, Ivan, asked me what I’d like to see, and looking over the list I saw the Concrete Crushing. That sounded a little bizarre, but he assured me it was really cool. So off we went. I figured it was going to be someone whacking concrete, or maybe snapping long pieces in half, something like that. What it turned out to be, though, was way, way cooler. See for yourself:

UIUC telescope
Despite being posed, I do in fact know how to use this thing.

Image credit: Margaret Gelman, Charles Gammie, the Univ. of Illinois Observatory

I can’t tell you how loud that crack was. Even as it was happening, I figured the cylinder would simply crack and fall apart, but it fairly well exploded. You can hear the kids screaming; they were farther away than I was and I assure you it scared the heck out of me.

My talk was a bit later, and I think it went pretty well. It was a good crowd, and I got a lot of questions after (including the very last question from a boy around the age of ten, who simply asked (somewhat exasperatedly) “When will aliens finally invade?” He got a round of laughing applause.

After the talk I visited the observatory and got a look at Jupiter and three moons through a wonderful old 30 centimeter (12 inch) refractor telescope. I love old beasts like that, and the view was pretty nice. The observatory is renovating the telescope as well, and they're looking for donors. Hint hint.

Finally, after all was done, we walked across campus for the Tesla coil concert. Tesla coils generate huge arcing spark discharge, and make that “ZZZZZzzzzzztttt!” sound so familiar from old monster movies. The pitch of the sound made by the arc can be varied using various methods, and you can then use that to create music. It’s an amazing experience, and the concert was really fun. Around a thousand people stood outside in the cold wind to listen, and everyone still had a fun time. Although I missed the first few seconds, I was able to get most of the Tesla coils playing the Doctor Who theme song on video:

How awesome is that?

I had a great time at UIUC, and I thank the engineering department for inviting me to speak, and showing me such a good time. If you live anywhere near Urbana-Champaign, you really should put this event in your calendar!