Date: Mon, 2 Feb 2004 14:27:49 -0800

Author: Doug Johnson

Subject: Re: vacuum bazooka

Post:

David,

My guess is that when you have multiple balls in the gun, that the
one ball closest to the end that is ruptured starts to turn and rub
against the next ball and climb up on it wedging itself between the
upper surface and the ball it is pushing. The second ball would want
to turn the opposite direction which would be creating a lot of
friction on the bottom of the tube. The more balls the greater the
friction.

My suggestion is to find some ping pong balls that are very smooth
and powder the balls and the tube with baby powder.


Best of luck! ...Doug J.


Greetings all,

I'm working on getting a version of the ping pong ball/vacuum bazooka
on "The Tonight Show with Jay Leno", but their special effects team
have encountered some problems. They made a 10 foot bazooka from
smooth, clear plastic tube. It works with one ball, but they wish to
preferably use several balls at a time (TV always seems to want
everything "bigger"). Sometimes it works well with several balls, but
at other times the balls hardly move. Does anyone have any experience
using several balls and/or a smooth tube? Any advise on how to get this
demo to work well will be much appreciated (maybe a mention on the
show?) I have both five and ten foot versions in my lab, made from
white PVC that work well, except that the tape sometimes gets "sucked"
into the tube prematurly, I haven't had any problems with balls not
moving. I'm wondering if the somewhat dimpled surface on the inside of
the tubes I use may actually help. Any ideas?

cheers,

David Willey

P.S. I'm always looking for dramatic demos that we haven't done yet, if
you know of any suitable demos that are not on the following list I'd
love to hear about them.

Thank you all for your time, this is a great mailing list!!


Walking On Broken Glass

Dipping Hand In Molten Lead

Lying On A Bed Of Nails And Having A Concrete Block Smashed

Table Cloth Pull

Liquid Nitrogen And Packing Peanuts

Bowling Ball Pendulum

Hand On Fire Using Alcohol

Fire Tornado

Methane Mamba

Breathing Helium And Sulphur Hexaflouride

Thermite Reaction

Coffee Creamer Fireball

Smoke Ring Cannon

High Power Laser

Blowing Up A Pumpkin

Flame Oscilloscope

Colored Flames

Burning Magnesium In Carbon Dioxide

Walking On Eggs

Monkey And Gun

Blowing Up A Wedding Cake

55 Gallon Drum Collapse Using Steam

Ostrich Egg Into A Bottle

Toilet Paper Blower

Expanding Foam Columns

Shooting A Pencil Through A Board

Bike Wheel Twist To Show Conservation Of Angular Momentum

Hovercraft

Quicksand

Soda Bottle + Lifesavers Fountain

Bermuda Triangle

Burning Crackers In LOX

Aluminum And Chlorate Explosion

Chemiluminescence

Diaper Compound In Water

Latex Paint Cf. Cornstarch

Bicycle Wheel Gyroscopes

Square Wheeled Car

Rolling Chain

Cool-Gel

Cold Fire

Smoke And Fire Tornado

Liquid Nitrogen Cloud

Liquid Nitrogen Ice Cream

Balloons In Liquid Nitrogen

Methane Mamba Revisited



From pauld@exploratorium.edu Mon Feb 2 17:25:05 2004

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