Expert: Jayendra Upadhye - 9/20/2008

Question
QUESTION: Hi again Jayendra,

I'm hoping you can help me find some information.

I've read that Mercury's line of apsides is precessing at 5600 arcseconds per century (which is 1.56 degrees). Can you tell me the rates of precession for the other 8 planets? I cant find them anywhere.

Many thanks Robert




ANSWER: Hi Robert,
To my knowledge, That happens only for mercury, and that too because its perihelion is fairly close (enough) to the sun.

Other planets do not exhibit this as far as i know, as no reference to any appreciable perihelion precession has ever occured in any of my readings of other planets, anywhere.

The reason (frame dragging) is applicable only to satellites with close perihelions.

Exact relationship you may look up on wikipedia.

In 2001 I came up with a program I wrote in Quick basic 4.5, in which one could simulate multibody orbital systems. This program exhibited the same behaviour of perihelion precession, and i was quite amazed at that. Because I was using the most elementary newtonian equations of motion, which are well proven in themselves, I presumed this precession was a natural "given" for close perhelions, that i hadnt known about, and tried to dig up more info.
  
It was then that i came up with the mercury perihelion precession.
Then i tried to reason that because my program used discrete time intervals (approximating continuous time), it ended up showing this precession due to dicrepancies of "location" on account of discrteness of time intervals used for sampling.

Is it possible Time itself is not continuous but like all other physical quantities, made up of dicrete quanta, which leads to "missed frames", and resultant perihelion precession?

Meaning for some small quantum of time, there is no gravitational coupling between mercury and the sun, and it continues tangentially for a small while, then again is caught up and swung around...you get the drif.

But that is all in pet theory province..only between the both of us.

regards
Jayen

---------- FOLLOW-UP ----------

QUESTION: Hi Jayen,

All the Planets are precessing along their line of apsides its been observed since Newton's time. It was thought to be down to the planets all moving in anticlockwise orbits pulling any individual's orbit round a fraction. Mercury always stuck out though. Mercury precesses 5600 arcseconds a century 43 arcseconds were unaccounted for by Laplace (I think). This is what Einstien fixed with GR. Would really like to have precession rates for the other planets if you can get them. Or if you can point to a site. Not really a Question but would really appreciate it if you can help.

many thanks Robert

Answer
Hi Robert,
Yes!
1 - This is about lunar apside precession:-
http://en.wikipedia.org/wiki/Lunar_precession

2 - The erath's apsides precession is covered here:-
http://74.6.239.67/search/cache?ei=UTF-8&p=wikipedia+precession+of+apsides&fr=yf

3 - general apsis reference topic is here:-
http://www.reference.com/browse/Apsides?jss=1

4 - This is a very detailed discussion of anomalous precession (related to apsides precession), of 4 inner solar system objects.
Contains a lot of complex mathematics too:-
http://www.mathpages.com/rr/s6-02/6-02.htm

Hope that suffcies.
Robert I cannot help you more on this.
regards
Jayen