No subject


Sat Apr 14 15:14:45 EDT 2007


tangential velocity does indeed play an important role in the process
but no centrifugal forces.

Best regards
Ulrich Bangert, DF6JB=20

> -----Urspr=FCngliche Nachricht-----
> Von: time-nuts-bounces at febo.com=20
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Arnold Tibus
> Gesendet: Sonntag, 27. Mai 2007 22:52
> An: Discussion of precise time and frequency measurement
> Betreff: Re: [time-nuts] Pendulums & Atomic Clocks & Gravity
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> Hello Ulrich,=20
> is it not important to bring into the game the satellite's=20
> velocity in=20
> relation to earth (on a tangential straight path deviated by=20
> gravitational acceleration)?=20
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> 73,
> Arnold, DK2WT
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> On Sun, 27 May 2007 19:59:22 +0200, Ulrich Bangert wrote:
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> >Didier,
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> >> gravitational forces, so do objects in Lagrange points.=20
> These points
> >> represent areas where the centrifugal forces compensate for=20
> >> gravity....
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> >I am almost sure that this will again produce me a lot of trouble in=20
> >answering a lot of people but the idea that there are centrifugal=20
> >forces which compensate for gravity are one of the BIGGEST=20
> misconcepts=20
> >that one may have in physics at all although it is quite=20
> common and you=20
> >may find statements like that eben in (bad) physics textbooks.
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> >Centrifugal forces are so called fictitious forces which are only=20
> >observed from within accelerated systems. Normal physics is done in=20
> >inertial systems. In an inertial system consisting of earth and an=20
> >satellite there are only TWO forces available: The gravity force by=20
> >which earth attracts the satellite and the gravitational=20
> force by which=20
> >the satellite attracts earth. They are of the same magnitude but of=20
> >opposite direction. That is the reason why the "sum of=20
> forces" is zero=20
> >for the closed system consisting of earth and satellite. There is no=20
> >place for any other force like centrifugal or so because there is no=20
> >counterforce available that would make the sum of forces=20
> zero i case a=20
> >centrifugal force would exist. In case you like to discuss it a bit=20
> >please go on but be prepared that I will to blow your arguments into=20
> >little bits. A good idea to start with is to look after what=20
> Newton's=20
> >first law is saying about the behaviour of a body for which=20
> all forces=20
> >compensate each other. Is that what a satellite does???
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> >73 Ulrich, DF6JB
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> >> -----Urspr=FCngliche Nachricht-----
> >> Von: time-nuts-bounces at febo.com
> >> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Didier Juges
> >> Gesendet: Sonntag, 27. Mai 2007 16:54
> >> An: Discussion of precise time and frequency measurement
> >> Betreff: Re: [time-nuts] Pendulums & Atomic Clocks & Gravity
> >>=20
> >>=20
> >> For the same reason that a satellite in free fall is still=20
> subject to
> >> gravitational forces, so do objects in Lagrange points.=20
> These points=20
> >> represent areas where the centrifugal forces compensate for=20
> >> gravity from=20
> >> two objects instead of one for a regular satellite. The only=20
> >> way to be=20
> >> free from gravitation is infinite distance from mass,=20
> until someone=20
> >> actually invents the famous gravitational shield :-) I hope=20
> >> it comes in=20
> >> spray form...
> >>=20
> >> Didier
> >>=20
> >> Neville Michie wrote:
> >> > Look up Lagrangian points on Wikipedia.
> >> > There are points of zero gravitational force, about our planet.=20
> >> > What is more, these points are stationary with respect=20
> to Earth, so
> >> > Doppler effects would be zero.
> >> > As the distance from Sun to Earth to Moon varies through=20
> >> the year it
> >> > follows that the distance from Earth of these points must
> >> vary on a
> >> > small scale.
> >> > These points are good for satelites as the orbit never decays.=20
> >> > cheers, Neville Michie
> >> >
> >> >  =20
> >> >> _______________________________________________
> >> >> time-nuts mailing list
> >> >> time-nuts at febo.com
> >> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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