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!
---------- Forwarded message ----------
Date: Thu, 21 Feb 2002 11:19:36 -0800
From: Simon Field <sfield@scitoys.com>
To: sfield@scitoys.com
Subject: New Science Toy: The Gauss Rifle -- A Magnetic Linear Accelerator
We've added a new toy at "http://scitoys.com"; 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.