Date: Sat, 23 Feb 2002 21:45:08 +0100

Author: Adolf Cortel

Subject: Re: "Newton's Cradle," but with gain


Hi Urs,
This experiment has run more than you imagine. I saw it about one year ago at CERN
(during the meeting of Physics on Stage). Some people from a Dutch science museum
showed a slope with alnico magnets and balls climbing along it. I built (copied+
simplified) this gadget using inexpensive Radio Shack ceramic magnets glued (hot
glue) to an aluminium profile. And it works wonderfull well!
Adolf Cortel

Urs Lauterburg wrote:

> Bill et al.
> This is something I have build a few years back and I even discussed it on
> this list at that time. Some people have inquired then and I explained how
> I did it. So it is kind of interesting to have the exact thing pop up now
> as something new. My setup looks very similar but I have even more pairs of
> steel balls stuck to strong neodym magnets mounted along a long aluminium
> rail. The device works well but one problem is the decreasing of the
> magnetic remanence due to the knock the magnets get every time from the
> accelerated balls every time you let the gun shoot. I wonder if Mr. Fields
> solved this problem with his device.
> Anyway it is a fun device to watch and contains quite evolved physics.
> Take care and kind regards
> Urs
> Urs Lauterburg
> Physics Demonstrator
> University of Bern
> Switzerland
> >Here's something I've never seen before. S.Q.Field has discovered a way
> >to make an electromagnetic mass driver which uses permanent magnets only.
> >It's a variation on "Newton's Cradle", but where the steel ball exits the
> >system at much greater velocity than the first ball entered. (see
> >attached message below.)
> >
> >So, how many balls and magnets would be needed to exceed the speed of
> >sound in air? Or to attain relativistic velocities? :)
> >
> >Mr. Field sells the spheres and supermagnets on his website. N.B. he also
> >sells small amounts of pyrolytic graphite (used for diamagnetic levitation
> >demos), and a 144F low-melting-point alloy (similar to Wood's metal.) Fun
> >stuff!
> >
> >(((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))
> >William J. Beaty SCIENCE HOBBYIST website
> >
> >EE/programmer/sci-exhibits science projects, tesla, weird science
> >Seattle, WA 206-789-0775 sciclub-list freenrg-L vortex-L webhead-L
> >
> >
> >
> >---------- Forwarded message ----------
> >Date: Thu, 21 Feb 2002 11:19:36 -0800
> >From: Simon Field
> >To:
> >Subject: New Science Toy: The Gauss Rifle -- A Magnetic Linear Accelerator
> >
> >We've added a new toy at "" that we've been having great
> >fun with.
> >
> >It shoots a steel marble at high speed, using only permanent magnets for
> >propulsion.
> >
> >You can build it in a few minutes by taping some magnets onto a wooden ruler.
> >All of the instructions can be found at
> >
> > ""
> >
> >along with lots of pictures, and an explanation of the science that makes
> >it work.
> >
> >The ball shoots through the device in 1/15th of a second, making a wonderful
> >clacking sound as it is accelerated from one magnet to the next. Everyone who
> >sees it fire gasps and laughs in surprise at the speed and simplicity of
> >this little toy.
> >
> >Have fun!
> >
> >Simon Quellen Field