greg
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Post by greg on Jun 19, 2015 20:51:54 GMT
Oh well, seems like we can't paste links here. Let's try again.
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greg
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Post by greg on Jun 19, 2015 21:18:09 GMT
Noting that this is dT/dt and the derivative attenuates longer periods the circa 13y peak is quite significant in the inter-decadal time-scale. Full article discussing this here: climategrog.wordpress.com/2013/03/01/61/Circa 9y periodicity is of lunar origin : precession of lunar aspides, which determines the timing and position of lunar perigee. It is that period that I suspect may be linked in a non-obvious way to Jupiter. I've found a remarkable coincidence of lunar cycles that produces 11.86 years, but explanation needs firming up. For the moment it could just be numerology but it's so close that it seems unlikely.
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Post by Andrew on Jun 20, 2015 6:55:26 GMT
If EM orbited the SSB then deviations in perihelion would be similar to SC-SSB distances and they are not. Hopefully that gives you a definitive answer to the question. Hi Greg When I contacted you, I had in mind this Tallblokes thread. tallbloke.wordpress.com/2013/02/20/lawrence-wilson-expert-opinion-on-the-earths-orbit-in-relation-to-solar-inertial-motion/comment-page-1/The Earth Sun distance is not in dispute by either myself or Geoff, and neither Geoff or myself believe the Earth orbits the SSBC. The issue that came up at Tallblokes, was your view the Sun was not moved by the planets? Unfortunately that PDF at JPL, which tallblokes referred you to, is now a failing URL so I was not able to follow it up. The PDF is not important though. The Sun must accelerate towards a planets gravity by some amount.
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greg
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Post by greg on Jun 20, 2015 7:42:28 GMT
HI Andrew, as I asked gsharp, if you want to question something I said, please quote it so that I can respond. I can not respond to what you think I said somewhere that you do not identify.
I explained all this in quite some detail to you by email yet you are still not understanding a basic difference.Many others on the SSB trip are making the same confusion.
Yes the planets do exert a gravitation force on the sun that affects its position. This is the curly locus shown on the WP page and it is caused by the planets constantly varying relative positions.
The confusion arises when people, including yourself, confuse centre of mass of the planets at any give instant with the direction of vector sum of all the planetary gravitational forces. The centre of mass is not the centre of all gravitational forces since no such centre can exist. Forces act between two bodies. The vector sum of many forces has a direction and magnitude, it does not have a point source. In the simple case of a two body system this line of force passes through the barycentre. That is not the case for 3 or more bodies.
Also the centre of mass is calculated using m*r and gravity is m*r^2 so clearly the two are not going to be the same. Venus is close enough to have a measurable effect on the net gravitational pull but is negligible in working out the centre of mass.
The line of the resultant force will be roughly in the direction of the barycentre but only roughly and the magnitude of the net force is NOT the same as the gravitational attraction of the total planetary mass sitting at the barycentre.
I am focusing on the EM distance from the sun because that is what we are discussing: the orbit. I have produced actual numbers that show the earth's orbit, while affected by the planets, is most closely tied to SC not SSB.
My dispute with Roger Tattershall was that neither the SSB nor the planet-sun barycentre is the correct solution for a multi-body system, though the latter is a much closer approximation, it is still technically wrong. We see from my graph above, which is similar to what we discussing on Tallblokes Tossshop, that there is significant deviation from a simplistic two body barycentric orbit and these variations may well be relevant to interdecadal climate variations.
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Post by Andrew on Jun 20, 2015 7:58:44 GMT
HI Andrew, as I asked gsharp, if you want to question something I said, please quote it so that I can respond. I can not respond to what you think I said somewhere that you do not identify. I explained all this in quite some detail to you by email yet you are still not understanding a basic difference.Many others on the SSB trip are making the same confusion. Yes the planets do exert a gravitation force on the sun that affects its position. This is the curly locus shown on the WP page and it is caused by the planets constantly varying relative positions. The confusion arises when people, including yourself, confuse centre of mass of the planets at any give instant with the direction of vector sum of all the planetary gravitational forces. The centre of mass is not the centre of all gravitational forces since no such centre can exist. Forces act between two bodies. The vector sum of many forces has a direction and magnitude, it does not have a point source. In the simple case of a two body system this line of force passes through the barycentre. That is not the case for 3 or more bodies. Also the centre of mass is calculated using m*r and gravity is m*r^2 so clearly the two are not going to be the same. Venus is close enough to have a measurable effect on the net gravitational pull but is negligible in working out the centre of mass. The line of the resultant force will be roughly in the direction of the barycentre but only roughly and the magnitude of the net force is NOT the same as the gravitational attraction of the total planetary mass sitting at the barycentre. I am focusing on the EM distance from the sun because that is what we are discussing: the orbit. I have produced actual numbers that show the earth's orbit, while affected by the planets, is most closely tied to SC not SSB. My dispute with Roger Tattershall was that neither the SSB nor the planet-sun barycentre is the correct solution for a multi-body system, though the latter is a much closer approximation, it is still technically wrong. We see from my graph above, which is similar to what we discussing on Tallblokes Tossshop, that there is significant deviation from a simplistic two body barycentric orbit and these variations may well be relevant to interdecadal climate variations. Greg, I totally agree with your first email and I cannot see any problems with this reply either until you begin talking about Roger.
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greg
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Post by greg on Jun 20, 2015 9:28:18 GMT
Without knowing what he thinks he is referring to, it is impossible to comment. IIRC that was about the stage he started ranting : RTFM about the JPL doc that he had apparently not read or understood himself. But when people start getting hot under the collar it rarely leads to a satisfactory resolution of any misunderstandings or technical differences of opinion.
I have not the slightest wish of "reconcile" with someone that childish who allows himself toddler fits and bans those who not agree with him. He has some good contributors but if there is not open scientific discussion it's not worth contributing.
He is in the same class Grant "Tamino" Foster who starts an argument and throwing insults then runs to hide behind a closed door. Enough of that.
I should still have a copy of JPL doc if you can point to the link, I may be able to find it. It wasn't that relevant to the discussion since JPL models are based on physics not barycentres.
We can see from the above graph that the EM system does not revolve about the SSB, nor the solar centre nor the E-M-S barycentre.
The best simple approximation would be the centre of the sun as is usually taught in schools. Deviations from that simplistic ideal are not usefully explained by talking about barycentres.
JPL provides incredibly precise trajectories and the results are what I plotted above. It would be worth looking at how that may affect climate. I'm trying to simulate the circa 13y cycle that appears to mix with the jovan periodicity. Since I have already detected a 13y period is several NH SST records, this is of particular interest if it can be linked to orbital variations.
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greg
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Post by greg on Jun 20, 2015 9:56:04 GMT
"The issue that came up at Tallblokes, was your view the Sun was not moved by the planets?"
That was not my opinion then and is not now. Again, if you think you see something contrary to that, please quote my words, don't give me your interpretation of what you think I said.
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Post by Andrew on Jun 20, 2015 10:23:06 GMT
"The issue that came up at Tallblokes, was your view the Sun was not moved by the planets?" That was not my opinion then and is not now. Again, if you think you see something contrary to that, please quote my words, don't give me your interpretation of what you think I said. I realise now I misunderstood what you were saying. The only thing remaining for me to work through mathematically is Neptunes influence upon the Sun compared to the inner planets. I am thinking at the moment that 80 years of tiny acceleration might amount to a significant amount of movement eventually? However, Neptune is only 17.147 Earth masses and is 4,500,000,000km from the Sun. The acceleration the Sun experiences by my calculation is 0.000,000,000336ms-2. If you draw out a circle and mark 10 degrees either side of a single direction, it is a reasonable approximation to say the Sun is pulled in only one direction for 9 years giving 13,000km of Solar movement For the Earth Sun Barycenter/CoM the distance is 500km. So all the inner planets will not amount to much at all All of this being relevant for this conversation: tallbloke.wordpress.com/2013/03/02/greg-goodman-lunar-solar-influence-on-sea-surface-temperature/-------------------------- Greg Goodman says: March 3, 2013 at 12:00 am TB:I contend that SIM shouldn’t be ignored…However, Neptune has an effect on solar inertial motion much larger than inner planets It does ? How? -------------------------- tallbloke says: March 3, 2013 at 12:10 am By having a considerably bigger mass and a much slower orbit. ------------------------- Greg Goodman says: March 3, 2013 at 12:35 am I don’t think you’re totally free of barycentre thinking here.
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greg
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Post by greg on Jun 20, 2015 11:38:18 GMT
"I realise now I misunderstood what you were saying. " Ah, you see the advantage of having to quote what someone said? It was TB, by insisting on earth-sun barycentre as the centre of earth orbit who was effectively saying other planets did not matter. He berated me in emails for being to picky and told me to take it somewhere else, before banning me permanently from his Toss-shop. The follow up was: >> Greg Goodman says: March 3, 2013 at 12:35 am I don’t think you’re totally free of barycentre thinking here. Could you try to express mathematically what kind of effect you think matters ? Maybe I’m missing the point. > That "barycentre thinking" seems to be what send into palpitations. He never did reply with a mathematical explanation of why a very, very distant planet should be significant. It could affect the position of the SSB but then the whole of the other thread was about debunking the SSB idea. Replacing one barycentre with another one does not seem too logical having established that barycentres are not the point of attraction. It seems to me that talk of SIM is just a back-door way of arguing for SSB. I may be missing something but TB was unable to come up with anything concrete. In fact, he did not reply to the question. The only way I see SSB being useful is on interstellar scales, where it can represent the mass of SS. In that context any movement of 1 solar raduis will be insignificant anyway.
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greg
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Post by greg on Jun 20, 2015 11:43:07 GMT
Neptune's period is about 7 times longer than Jupiter's. It's gravitational pull is several order of magnitude smaller. It has more effect on SSB but unless SSB matters in some way, I can't see Neptune getting a look in.
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greg
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Post by greg on Jun 20, 2015 11:47:36 GMT
I've emailed you the JPL chapter 8
>> For the final (integration) phase of the ephemeris creation process, there are three main ingredients, each of which constitutes a major phase itself: • the equations of motion describing the gravitational physics which govern the dynamical motions of the bodies, • a method for integrating the equations of motion , and • the initial conditions and dynamical constants; i.e., the starting positions and velocities of the bodies at some initial epoch along with the values for various constants which affect the motion (e.g., planetary masses).
>>
No mention of barycentres.
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greg
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Post by greg on Jun 20, 2015 11:52:28 GMT
I found this I calculated at the time. Relative m/r^2 ratios taking earth as unity.
m/r2 ==== Hg=0.3672 V=1.559 E=1 Ma=0.1615 J=11.733 S=1.0363 N=0.0189 U=0.0393
Neptune has less gravitational effect on the sun than tiny Mercury ! Three orders less than Jupiter. Even pulling one way for seven times longer, it is peanuts.
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Post by Andrew on Jun 20, 2015 11:57:35 GMT
Neptune's period is about 7 times longer than Jupiter's. It's gravitational pull is several order of magnitude smaller. It has more effect on SSB but unless SSB matters in some way, I can't see Neptune getting a look in. (I apologise for editing my posts on the fly) By my estimation what you first said on tallblokes in that particular thread about Neptune is not correct. The mathematical point of the SSBC moves only a few thousand km via the inner planets I believe. By my calculation, as an approximation, Neptune in only 9 years, (which is 10 degrees of Neptunes movement either side of a single vector) will cause the sun to move along that single vector a distance of 13,000km. I could be way out on that but it appears a reasonable estimation.
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Post by Andrew on Jun 20, 2015 12:04:18 GMT
I found this I calculated at the time. Relative m/r^2 ratios taking earth as unity. m/r2 ==== Hg=0.3672 V=1.559 E=1 Ma=0.1615 J=11.733 S=1.0363 N=0.0189 U=0.0393 Neptune has less gravitational effect on the sun than tiny Mercury ! Three orders less than Jupiter. Even pulling one way for seven times longer, it is peanuts. Give me a moment please to look at the distances involved with the inner planets
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Post by Andrew on Jun 20, 2015 12:23:25 GMT
I found this I calculated at the time. Relative m/r^2 ratios taking earth as unity. m/r2 ==== Hg=0.3672 V=1.559 E=1 Ma=0.1615 J=11.733 S=1.0363 N=0.0189 U=0.0393 Neptune has less gravitational effect on the sun than tiny Mercury ! Three orders less than Jupiter. Even pulling one way for seven times longer, it is peanuts. By my estimation in the 5 days it takes Mercury, and the 9 years it takes Neptune to travel 20 degrees of orbit, and assuming the pull is only in one direction, Mercury moves the Sun 4km and Neptune moves the Sun 13,000km The orbit of mercury is 88 days and Neptune 165 years.
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