On 12/15/2009 02:09 PM, Jed Rothwell wrote:
The battery is puzzling, but they do not hide it, so I do not see how it
could be part of a scam.
Mark Iverson wrote:
so it should be easy to demonstrate that this thing could be kept
running for weeks, months when it should draw down the battery in a
matter of days...
Hours, not days. Toys that operate with D batteries run out in an hour
or so.
Wrong comparison. D-cell powered toys are typically doing significant
work. On the other hand, small induction motors that do nothing but
rotate do *not* run down a small battery in an hour or so. These things
have been desktop novelties for a long time -- the ones I've seen
typically had one moving part which just ran back and forth across a
track. With very low friction, and almost no losses except air
resistance, they can keep going for a very long time.
See, for instance, this site (these aren't what I was thinking of;
they're far fancier than the old metal-and-plastic spinning rotor
desktop novelties; none the less they're the same idea):
http://www.allwaze.com/woodcraft-hover.htm
Quote from the blurb on the page:
Batteries are used to overcome the air friction losses and simply give
the moving arm a 'kick' each time it passes the base. Each Levitating
Motion Sculpture takes four AA batteries, and will continue to rotate
from several months to a year,
Sounds about like the battery life Steorn is claiming -- and 1 D cell,
ala Steorn, may be worth 3 or 4 AA cells, depending on the battery
technology.
If it produces significant movement and noise
Who said anything about noise?
