Ulrich, From NASA: http://map.gsfc.nasa.gov/m_mm/ob_techorbit1.html
<quote> More precisely, the *Lagrange Points* mark positions where the gravitational pull of the two large masses precisely equals the centripetal force required to rotate with them. </quote> I am in good company :-) (except that I used the term "centrifugal" instead of "centripetal") Didier KO4BB Ulrich Bangert wrote: > Didier, > > >> gravitational forces, so do objects in Lagrange points. These points >> represent areas where the centrifugal forces compensate for >> gravity.... >> > > I am almost sure that this will again produce me a lot of trouble in > answering a lot of people but the idea that there are centrifugal forces > which compensate for gravity are one of the BIGGEST misconcepts that one > may have in physics at all although it is quite common and you may find > statements like that eben in (bad) physics textbooks. > > Centrifugal forces are so called fictitious forces which are only > observed from within accelerated systems. Normal physics is done in > inertial systems. In an inertial system consisting of earth and an > satellite there are only TWO forces available: The gravity force by > which earth attracts the satellite and the gravitational force by which > the satellite attracts earth. They are of the same magnitude but of > opposite direction. That is the reason why the "sum of forces" is zero > for the closed system consisting of earth and satellite. There is no > place for any other force like centrifugal or so because there is no > counterforce available that would make the sum of forces zero i case a > centrifugal force would exist. In case you like to discuss it a bit > please go on but be prepared that I will to blow your arguments into > little bits. A good idea to start with is to look after what Newton's > first law is saying about the behaviour of a body for which all forces > compensate each other. Is that what a satellite does??? > > 73 Ulrich, DF6JB > > >> -----Ursprüngliche Nachricht----- >> Von: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] 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 >> >> >> For the same reason that a satellite in free fall is still subject to >> gravitational forces, so do objects in Lagrange points. These points >> represent areas where the centrifugal forces compensate for >> gravity from >> two objects instead of one for a regular satellite. The only >> way to be >> free from gravitation is infinite distance from mass, until someone >> actually invents the famous gravitational shield :-) I hope >> it comes in >> spray form... >> >> Didier >> >> Neville Michie wrote: >> >>> Look up Lagrangian points on Wikipedia. >>> There are points of zero gravitational force, about our planet. What >>> is more, these points are stationary with respect to Earth, so >>> Doppler effects would be zero. >>> As the distance from Sun to Earth to Moon varies through >>> >> 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. >>> cheers, Neville Michie >>> >>> >>> >>>> _______________________________________________ >>>> time-nuts mailing list >>>> [email protected] >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> >>>> >>> _______________________________________________ >>> time-nuts mailing list >>> [email protected] >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> >>> >>> >> _______________________________________________ >> time-nuts mailing list >> [email protected] >> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts >> >> > > > _______________________________________________ > time-nuts mailing list > [email protected] > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
