Re: gyro wheel (fwd)

Date: Mon Dec 30 2002 - 19:02:31 PST

Hello Petra

A variation on your experiment has been done by placing a gyroscope on a digital

The experimenters published the results that you predicted, that the scale
registered less weight when the wheel was rotating.

Alas a careful repeat of the experiment showed that their results were in error.
Scales are made to weight motionless objects. They sometimes give erroneous
results when the object vibrates or rotates.

But, you should try your experiment anyway, "unperformed experiments have no

Paul Doherty
Senior Staff Scientist

> Have you tried what he suggest?
> If so, could you let him or me know?
> Thanks,
> Deb
> ________________________
> Deb Hunt
> Snacktalk Moderator
> Exploratorium
> 3601 Lyon Street
> San Francisco, CA 94123-1099
> ---------- Forwarded message ----------
> Date: Tue, 3 Dec 2002 12:20:58 +0200
> From: Petrache Vicentiu <>
> To:
> Subject: gyro wheel
> Dear Nina,
> My name is Vicentiu Petrache and I'm from Romania (Europe)
> The experiment of bicycle wheel is very interesting but I would ask you
> if somebody have tried to weigh the wheel before and along the
> experiment because I think the wheel will get more light as long as
> rotating!
> I'm going to do this experiment using a project presented on the
> attachement.
> As you can see the experiments is consisting of:
> -an about 1 kg metal flywheel fixed on a shaft
> -this group is mounted on two bearings
> -the shaft is rotated by an electrical engine (say one of a vacuum
> cleaner)
> to 20 000 revolutions/minute
> -the two bearings together the flywheel and its shaft are suspended (say
> from the ceiling) using two wires A and B.
> -from wire A a scale is connected.
> -after starting the engine (fixing by hand the group at starting point
> in order to be stable) the shaft will be disconnected from the shaft
> using the clutch engine being separated completely.
> -the B wire will be cut off and the group will start to rotate around
> the A wire.
> -at this moment we read the weight on the scale
> -after the reading we can wait for the goup to stop or to stop it in a
> voluntary way and after all is quiet we can read again the scale.
> -I would bet the the group is heavier when is quiet than in rotation.
> What is your opinion?
> As soon as I'll be able to have money to do this experiment I'll do it
> but if there is someone to try this I would be gratefull to be
> acknowledged.
> Thank you very much for your kindness and I'm waiting for your answer..
> my e-mail is:
> <>
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