Burning paper with giant steel balls

Burning paper with giant steel balls

I bought these enormous ball bearings from this guy. They're fantastically heavy. When you whack them together you get a lovely sound. But for that brief moment and in that small space you also get really high temperatures and you can easily burn holes in paper. Here's a video:

You can even smell it! Here's a close up:

Burning paper with giant steel balls

You might also like this fire tornado I made.

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This entry was posted on Friday, November 13th, 2009 at 10:12 pm and is filed under Science. You can follow any comments to this entry through the RSS 2.0 feed. You can leave a comment, or trackback from your own site.

  • Wesly

    Hello, I am doing a research on the phenomena, can you plz give the information about the weight of the steel balls and perhaps the velocity? Thank you very much!

  • Wesly

    Hello, I am doing a research on the phenomena, can you plz give the information about the weight of the steel balls and perhaps the velocity? Thank you very much!

  • http://www.stevemould.com Steve Mould

    Hi Wesly, I’m not sure about the velocity but the balls are 60mm in diameter. So that’s 0.03m radius. So the volume is 4/3*pi*0.03^3 = 0.13×10^-4 m^3. The density of steel is about 7,500 kg/m^3.

    So the mass is just those two multiplied together 0.13×10^-4 * 7,500 = 0.85kg.

    The weight is just the mass times the acceleration due to gravity (9.8m/s^2) = 8.3 Newtons

  • http://www.stevemould.com Steve Mould

    Hi Wesly, I’m not sure about the velocity but the balls are 60mm in diameter. So that’s 0.03m radius. So the volume is 4/3*pi*0.03^3 = 0.13×10^-4 m^3. The density of steel is about 7,500 kg/m^3.

    So the mass is just those two multiplied together 0.13×10^-4 * 7,500 = 0.85kg.

    The weight is just the mass times the acceleration due to gravity (9.8m/s^2) = 8.3 Newtons

  • Anonymous

    If you’re interested, I believe you can obtain an interesting result if you do the same thing with aluminum foil as opposed to paper.

  • http://blog.stevemould.com Steve Mould

    Really good idea. I do that in live shows. I tried to get video of it but it’s hard to get the lighting and stuff right. It’s a great demo though.

    You actually have to rust the balls first because what you get is a chemical reaction between the aluminium and the rust (iron oxide). It’s called the thermite reaction and you get a brilliant flash and bang.

  • 6Revolvers

    Cool stuff you got there.

    Thank Stumbleupon that i stumbled upon this ;)

  • http://blog.stevemould.com Steve Mould

    I’m getting so much traffic from stumbleupon. Complete mystery.

    Glad you like it!

  • Dawoee

    Mystery? Stumbleupon is the only way to waste time!

  • http://blog.stevemould.com Steve Mould

    It’s pretty dangerous in fact!

  • Jeeemeister

    I “stumbledupon” this site too.

    Pretty interesting stuff Steve. Keep up the good work!

    Jim, in Southern Thailand

  • http://jimsjournal.blogspot.com Jeeemeister

    By the way Steve…the video doesn’t work for me.

    Say’s “An error occurred, please try again later.”

    Jim in Southern Thailand

  • http://blog.stevemould.com Steve Mould

    Thanks Jim! And thanks for telling me about the error. Looks OK now. Hopefully just a glitch with youtube.

  • Uncle B

    Science novelties ! Great stuff ! Do more ! Gotta have more !

  • http://blog.stevemould.com Steve Mould

    Thanks!

  • http://jimsjournal.blogspot.com Jeeem

    Yep! Video works now. Thanks.

    -Jeeem-