Re: Gyroscopes - Usenet Physics FAQ - Reference frames

From: JM Albuquerque (jm.aREMOV.E_at_sapo.pt)
Date: 07/26/04 

Date: Mon, 26 Jul 2004 22:46:27 +0100

"Uncle Al" <UncleAl0@hate.spam.net> wrote:
> JM Albuquerque wrote:
> >
> > Around these newsgroups there are current discussions about
> > inertia, mass, centrifugal force, equivalence principle, gravity, etc.
> >
> > I've looked at the Physics FAQ:
> > http://math.ucr.edu/home/baez/physics/index.html
> >
> > And I've notice the following:
> > 1 - Gyroscopes don't belong to Physics.
> > 2 - Centrifugal force doesn't even exist.
> > 3 - Gravity also is a fictitious force like the centrifugal force.
> > http://math.ucr.edu/home/baez/physics/General/Centrifugal/centri.html
> > (See at bottom: Could gravity be a fictitious force too? YES.)
> >
> > Why gyroscopes don't belong to the actual Physics is the point.
>
> Idiot.
>
> Google
> luo gyroscopes 198 hits

So, you got 198 hits.
Read them and see for yourself.

And what about the basic question?
Please explain why a bicycle wheel don't fall under gravity, if a
precession motion exists?
Please explain this:
http://physics.nad.ru/Physics/English/gyro_tmp.htm
http://physics.nad.ru/Physics/English/gyro_txt.htm
And with 4Mb size the bicycle wheel:
http://www.rci.rutgers.edu/~williebo/zzzgyrovideo.MPG
(The usual bicycle wheel precessing around a vertical axis which doesn't
fall and turn around if allowed to do so).

What happened to the space-time curvature, near the bicycle wheel, in order
not to fall to the ground, like every other non rotating mass will do?
Is there any reasonable explanation why the bicycle wheel doesn't fall?

At such a small speed, how does GRT explain that the bicycle wheel doesn't
fall? Gyroscopes show that locally the space-time curvature clear depends on
the angular speed of the solid body.
No rotating speed and it will fall.
Just spin the body a little and it will not fall. Why?

> Did you find an old copy of Heinleins' "Number of the Beast?"
>
> > Physics goes for inertial reference frames (those non rotating) and
> > simply discard the rotating frames of reference.
>
> Idiot. The Weak Equivalence Principle extends to the Strong
> (Einsteinian) Equivalence Principle :
>
> 1) Non-rotating free fall is locally indistinguishable from
> uniform motion absent gravitation. Linear acceleration relative
> to an inertial frame in Special Relativity is locally identical
> to being at rest in a gravitational field. A local reference
> frame always exists in which gravitation vanishes.

Great news.
Obviously that a local reference frame always exists in which gravitation
vanishes, all you have to do is balance gravity. If gravity vanishes or not
its up to your believe.
Pick a weight and hold it for a day and see if gravity vanishes.

> 2) Local Lorentz invariance (absolute velocity does not exist)
> and position invariance. All local free fall frames are
> equivalent.

Yes in the radial direction.
Not if torque is applied to a rotating free fall body.

> 3) The Strong Equivalence Principle embraces all laws of
> nature; all reference frames accelerated or not, in a
> gravitational field or not, rotating or not, anywhere at any time
> (frame covariance; global diffeomorphism invariance aside from
> the Big Bang).

Wrong.
The invariance inside of the Universe is bull***.
The right hand applies for electromagnetism and gyroscopic torques.
Where is the invariance, since the right hand rules is required Doc?

A diffeomorphism is roughly the same as a change of coordinates,
though the technical definition applies even to spacetimes which
don't allow globally defined coordinates.
What matters most is not the coordinates of an object, but its position
relative to other objects. If we change our coordinate system, the
coordinates of all objects change without changing the actual physical
situation.
This insight means that all physically observable quantities are
"diffeomorphism invariant": they don't depend on our choice of
coordinate system.

The great news are that rotating reference frames do depend on our
choice of the coordinate system, since the right hand rule is required.

You cannot exert torque on a rotating object in space.
But you can apply force to that same object in space.
You can spin that object in space, but then you cannot apply any torque in a
direction at 90 degrees from the previous one.

> > Experts, please explain why a bicycle wheel don't fall under gravity, if
> > a precession motion exists?
>
> Idiot. If you want anti-gravity you need the manual transmission
> from a 1969 Honda, strobes, magnets, and liquid nitrogen fog.
> Podkletnov almost had it. Motocross proves spinning bicycle
> wheels fall.

Can't have antigravity. I'm not that idiot Uncle.
Ask yourself why spinning bicycle wheels fall but the motocycle won't turn
from the vertical position.

> [snip crap]
>
> > Remember Pioneer 10 going out of the solar system?
> > There is so many evidence that Physics must have taken the wrong
> > road some where that it almost stinks.
>
> Idiot. (There are two of them.)
>
> http://arxiv.org/abs/gr-qc/0205059
> Pioneer anomaly
> http://arXiv.org/abs/gr-qc/0307042
> Rationalized Pioneer anomaly
> http://arXiv.org/abs/gr-qc/9810085
> Believable rationalized Pioneer anomaly
> http://arXiv.org/abs/gr-qc/gr-qc/0310088
> Believable Pioneer anomaly updated

Thanks for the references.
All of them make my point.
Read them with your eyes open.
See the rotation issue?
Rotation is good, humm...

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