gravity effects

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21 years 9 months ago #4434 by tvanflandern
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>I would love to acquire the data you say my library needs. Can you tell me where this data is posted?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

The <i>Astronomical Ephemeris</i> published by the U.S. Naval Observatory annually has tables of the Sun that are used in the comparison with observations. They are known to match closely, but are much easier to understand and use than raw observations.

You can find full explanations of this material, including everything you ever wanted to know about the Sun's motion but were afraid to ask, in the <i>Explanatory Supplement to the Astronomical Ephemeris</i>. I recommend getting an old edition, say the one published in 1960, rather than the latest (1992) edition. The newer stuff addresses all wavelengths and higher-precision users, so it is necessarily a lot more technical. Even the old editions presume a lot of astronomy background, so you might need a glossary of terms handy. But mostly, it explains concepts from scratch with diagrams and simple formulas. -|Tom|-


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21 years 9 months ago #4318 by Jim
Replied by Jim on topic Reply from
I don't want to go round an round with this stuff, but, JPL horizon's has this info posted also. And as I said before when you get into the orbital details it is quite clear they use a barycenter model and have the moon pushing the Earth. This is why they have the Earth nearer to the sun when the moon is full than at new moon. I know this is very accurate to several decimals as far as numbers go. The point is still that this is mechanically and gravitationally wrong.

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21 years 9 months ago #3182 by tvanflandern
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[Jim]: when you get into the orbital details it is quite clear they use a barycenter model and have the moon pushing the Earth. This is why they have the Earth nearer to the sun when the moon is full than at new moon. I know this is very accurate to several decimals as far as numbers go. The point is still that this is mechanically and gravitationally wrong.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

It is true that the Earth is nearer to the Sun when the Moon is Full than it would be if there were no Moon. That is the logical consequence of ordinary pulling gravity. The conclusions you draw from that geometry are unwarranted and frankly unwelcome.

Look, Jim: Either you want to try to understand how Newtonian gravitation works, or you have already made up your own mind. If the latter is the case, you may now stop trying to use this Board as a forum for such outlandish ideas. It makes the whole Message Board look bad.

OTOH, it you do want to understand, then confine yourself to reading (you should be devouring several books a week) and asking questions until you have learned enough of the basics, intermediate concepts, and the advanced matters to mount a serious challenge. Okay?

IMO, no one should be questioning widely accepted knowledge until they fully understand how it came to be widely accepted in the first place. And the answer that "everyone is stupider than me" will not get you anywhere, even if it were true. -|Tom|-


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21 years 9 months ago #2875 by n/a3
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if I may just drop in...

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>

when you get into the orbital details it is quite clear they use a barycenter model and have the moon pushing the Earth. This is why they have the Earth nearer to the sun when the moon is full than at new moon.

<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

good chance to crank the old shaft...

If I recall correctly, the barycenter model assumes the common center of mass is unaccelerated and one of the two masses moves with it or is fixed wrt.. then that the plane of orbit is known and theta sub zero is set at the pericentron, to a zero value....that's the only way to solve the problem and get the constants of integration from the mechanical energy function...unless you do that, the problem has six second-order differential-- non-liner-- equations and only two integrals and two energy equations, that is to say it cannot be solved (if i recall correctly)... nevertheless, it is to my surprise that its solution seems to confirm measurements, unless and I mean that, measurements are smoothed out by the model predictions and are not based on pure radio signals bounded back and forth.

well jim, even if you study orbital mechanics for 50 years you'll never understand why is like that but only what's there... it's a religion pal...



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21 years 9 months ago #3848 by Jim
Replied by Jim on topic Reply from
Mark, Your post above refers to measurements of (I guess) redshifts that have been made of the orbit of the Earth/moon system. Can you tell me where this data can be accessed? I have been asking several sources here and on other sites that say as you do that this data exists and so far no one seems to know where it might be. Have you personally accessed any of this data or are you assuming it exists?

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21 years 9 months ago #4443 by n/a3
Replied by n/a3 on topic Reply from
i know that optical and radio measuremnts not match for sure.. astronomical data models such as from JPL are based on a combination of radio data and math model predictions...the noise level is to high in measurements and many assuptions are applied to get the ephemeris out...the files are in a special format and access is difficult unless one has some type of relational data base tool with specific high level object oriented commands...it a real mess...i don't think there exist any prediction based on pure radio signals...good luck to you...you'll need it...lol


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