Usually, and that means in the past year, when you look at the false color MDI image from SOHO, you can look at the corresponding magnetogram and see some sort of disturbance going on, even it it is not visible as a sunspot, sunspeck, or plage area.
Not today.
Left: SOHO MDI “visible” image Right: SOHO Magnetogram
Click for larger image
Wherefore art though, cycle 24?
In contrast, September 28th, 2001
Oh, my english- perturbation, moderator please correct.
Leif Svalgaard (08:18:47) :
Geoff Sharp (07:30:35) :
You were asserting [“move Earth closer to the moon and you would expect another trade off”] that there is a relation between distance and LOD and there is not.
————————————–
If you were to shrink the Moon’s orbit [moving the Earth closer to the Moon] the Earth would indeed speed up because of conversation of AM. similarly, if you were to shrink [make the semi-major axis smaller] the Jupiter’s orbit by 1.2 million km, the Sun would speed up. Shrinking Jupiter’s orbit by 1.2 million km every time around would make Jupiter crash into the Sun in 7688 years
I am wondering if you typed this correctly? You seem to be agreeing with me.
The Sun is constantly moving in relation to the barycenter, moving away for about 10 yrs then coming back for 10 years. This would have an acceleration/deceleration effect keeping the system in balance. The jovians are like yoyo’s on a string with no danger of crashing into the Sun or being flung into other galaxies. This also totally explains why we have stronger solar cycles when angular momentum is high, there is more acceleration/deceleration in the system. When we have a disturbance like we are entering now that normal pattern is disrupted, and in the case of Type “A” disturbance (inner loop) the Sun would normally be accelerating (majority of Jovians are closer) but that process is brought to a halt, perhaps entering a limbo state of very slow or zero acceleration/deceleration.
Check JPL as I described earlier and this is easily seen, The Sun is changing its distance to the Jovians everyday. The method I suggested eliminates any confusion associated with Aphelion/Perihelion distances.
There is no need to include any discussions about tides.
anna v (13:09:54) :
the tides expected if the sun were a ball of gas up to 0.1628 AU. If there were spin orbit coupling more than tidal effects, it would show.
The expected tide (h) can be calculated from h/R = (m/M) (R/a)^3
where radius of the body on which the tides will appear is R, its mass M and the distance to the body, with mass m, raising the tide is ‘a’.
Example [all mks or SI units] where I have used accurate values [from reference texts] rather than the usual ‘back-on-the-envelope’ numbers we remember by heart:
for Moon on Earth: M = 5.97E24, R = 6.378E6, m = 7.3483E22, a = 3.84403E8, h = 0.36752
for Jupiter on Sun: M = 1.99E30, R = 6.96E8, m = 1.8986E27, a = 7.7792E11, h = 0.0004765
Geoff Sharp (13:21:49) :
when angular momentum is high, there is more acceleration/deceleration in the system.
It seems we are back to square one. The angular momentum of the system is constant. The accelerations/decelerations cannot be felt in a free fall.
The Sun is changing its distance to all bodies of the solar system all the time, Jovians, Earth, comets, interplanetary dust, etc. The changing distance cannot be felt except for tidal forces. If you jump of the Eiffel Tower you will change the distance to the Earth all the time, but feel nothing [until the distance stops changing 🙁 ]. Barycenter or not, doesn’t matter.
Paul,
I would say what I just said (and spell, or pronounce, perturbation correct 🙂
Leif,
If there were only the Sun and Earth, would the Earth still orbit the Sun or the barycenter? If I add Jupiter why does the Earth no longer [per Geoff] orbit the [new] barycenter as well?
The Earth would orbit the barycenter, but that would be only 470 km (from memory) from the center of the Sun. When you add Jupiter the Earth will follow the Sun around the new BC because Jupiter’s orbit is outside Earth’s orbit.
(This time I think even Leif will agree, almost..)
Several people has now asked why the question is important? What difference would it make to the argument?
It’s important because the BC is the ‘fixed’ point of the solar system, so if Jupiter accelerates around the BC so does the Sun, which will change it’s rotation.
Carsten Arnholm, Norway (10:43:29) :
Here is an example I ran a few days ago.
Take a point in time, I chose June 20 1951. Measure J distance to Sun & SSB.
Move on 1 complete orbit of J, 4339 days later we find the J to SSB distance is exactly the same as in 1951.
This date is April 7 1963. Then measure J to Sun and compare with 1951 figure. The result is .0046AU longer, this translates to roughly 700,000 kilometers.
If we also measure the Sun to SSB distance over the same timescale we get .0053AU difference which looks to be perfect. The sun doesnt return to the 1951 position in 1963 so there is some loss in the arc and the full offset is not taken up.
Geoff Sharp (13:21:49) :
Leif Svalgaard (08:18:47) :
If you were to shrink the Moon’s orbit [moving the Earth closer to the Moon] the Earth would indeed speed up because of conversation of AM.
I realize now that this can [would] be misunderstood and taken out of context. What was meant was if you could change the orbit that would change the rotation. but the point that is missing is that you cannot change the orbit in the contemporary solar system except by friction which goes only one way. And perhaps drag by the solar wind’s magnetic field [which is minuscule]. When the solar system was first born, solar activity and the solar wind were MUCH stronger than today and did in fact change the orbits [making them larger] and slow the Sun’s rotation [from less than a day to 25 days] by magnetic braking of the Sun, thus transferring angular momentum to the planets – one of the reason the planets have several hundred times more AM than the Sun has now. Right now, noe of these mechanisms are effective and the orbits and solar rotation do not change, and such change there is, is one-way: slowing down the Sun [always].
idlex (10:41:59) :
The orbital period of Jupiter is 11.85920 yrs or 4331.57 days. According to my simulation model on 1 Jan 1940 the distance of Jupiter from the Sun is 7.4044526E11 m, and the distance of Jupiter from the SSB is 7.3948122E11 m. 11.85 years later takes us to early November 1951, when my simulation says the distances are 7.4027794E11 m and 7.4020631E11 m.
The Aphelion/Perihelion distances are masking whats going on in the background and they need to be stripped away to see the detail. This is probably why it has not been noticed in the past.
anna v:
Lets see if I understand this: The objective is to nail the spin orbit business by a different angle, by demonstrating that a ball bearing on a solid sun would get a tangential ( that is what transfers spin) motion consistent in size with the tides .
I wasn’t really thinking of the spin orbit business. I was thinking more about what sorts of things, which had nothing to do with the Sun’s angular momentum or spin momentum, might happen on the surface of the Sun.
The ball bearings (I was thinking of sprinkling quite a few of them liberally all over the sun) just seemed to be one way to think about events on the Sun’s surface. Maybe the ball bearings would do something obvious, like all collect under Jupiter. But I don’t think they would. I think they would maybe pursue some interesting “orbits” around the surface of the Sun. For example, if a ball bearing rolled all the way round the Sun towards Jupiter, then when it got to the point below Jupiter on the Sun’s surface it wouldn’t stop there, but would carry on moving, only now decelerating. Or so I imagine. Maybe I’d see something like “weather systems” of ball bearings eddying around on the surface of the Sun. The initial conditions would also have an effect. If I placed the ball bearings in stationary positions, they would all start to accelerate in one direction or other across the surface of the sun, and would take a while to ‘get their act together’. Or maybe I’d have to start with a Sun with no planets. Would the ball bearings go round and round on the rotating sun with no planets, and behave like islands? Or would they stay exactly where I’d put them, because there was no rolling resistance, the Sun turning under them?
I really don’t know how they would behave. But my simulation model might be able to tell me. Whether it would be meaningful experiment is another question, because the Sun isn’t really like that at all.
I think that a heliocentric satellite would change rotation rate so would lose synchronization , the magnitude should be commensurate with the tides expected if the sun were a ball of gas up to 0.1628 AU. If there were spin orbit coupling more than tidal effects, it would show. I am hand waving of course.
It’s an interesting wave of the hand, though. But I think there are two separate ‘experiments’ here. I agree that the satellite would lose synchronisation, because it would always be being tugged forwards or backwards by the planets, and going too fast or too slow. If it moved too fast, it would move further away from the Sun, and if too slow it would move nearer the Sun (something the ball bearings can’t do). And, if they are to be in heliostationary orbit, these satellites would have to be restricted to the Sun’s equatorial plane. The ball bearings could be put anywhere.
Roger Clague (01:55:45) :
http://www.wxresearch.org/papers/orbit2004.htm
I was in contact with Jill Hasling last week when looking for some evidence on the Jovian orbit point. Their papers inspired me to look further. Sadly Dr. Freeman passed away Nov 2004.
Leif Svalgaard (13:40:39) :
What was meant was if you could change the orbit that would change the rotation. but the point that is missing is that you cannot change the orbit in the contemporary solar system except by friction which goes only one way.
But we ARE seeing a change in orbit of the Jovians not related to friction?
lgl (13:47:51) :
The Earth would orbit the barycenter, but that would be only 470 km (from memory) from the center of the Sun. When you add Jupiter the Earth will follow the Sun around the new BC because Jupiter’s orbit is outside Earth’s orbit.
(This time I think even Leif will agree, almost..)
So if I add Pluto, it would follow the Sun because Jupiter in inside Pluto’s orbit. And even the Sun is inside Jupiter’s orbit. No, this is nonsense.
so if Jupiter accelerates around the BC so does the Sun, which will change it’s rotation.
No, as we have seen so many times. There is no transfer of AM.
Here is What Shirley of JPL has to say:
Axial rotation, orbital revolution and solar spin–orbit coupling
James H. Shirley
Jet Propulsion Laboratory, California Institute of Technology, MS 183-601, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
Accepted 2006 January 19. Received 2005 November 23
ABSTRACT
The orbital motion of the Sun has been linked with solar variability, but the underlying physics remains unknown. A coupling of the solar axial rotation and the barycentric orbital revolution might account for the relationships found. Some recent published studies addressing the physics of this problem have made use of equations from rotational physics in order to model particle motions. However, our standard equations for rotational velocity do not accurately describe particle motions due to orbital revolution. The Sun’s orbital motion is a state of free fall; in consequence, aside from very small tidal motions, the associated particle velocities do not vary as a function of position on or within the body of the Sun. In this note, I describe and illustrate
the fundamental difference between particle motions in rotation and revolution, in order to dispel some part of the confusion that has arisen in the past and that which may yet arise in the future. This discussion highlights the principal physical difficulty that must be addressed and overcome by future dynamical spin–orbit coupling hypotheses.
P.S. Shirley used to believe in this [has published papers with Fairbridge], but has seen the light. The bottom line is that if one wants to believe in the correlations, there is no known physical mechanism. So, one can cross out: “so if Jupiter accelerates around the BC so does the Sun, which will change it’s rotation”. It will not.
Geoff Sharp (13:58:10) :
The Aphelion/Perihelion distances are masking whats going on in the background and they need to be stripped away to see the detail. This is probably why it has not been noticed in the past.
How do you ‘strip away’ the distances? and what has not been ‘noticed in the past’?
Leif Svalgaard (14:59:55) :
Geoff Sharp (13:58:10) :
The Aphelion/Perihelion distances are masking whats going on in the background and they need to be stripped away to see the detail. This is probably why it has not been noticed in the past.
How do you ’strip away’ the distances? and what has not been ‘noticed in the past’?
You might need to read back, some of my comments were caught in the moderation queue.
To see the changing length of the semi-major axis between the Sun and Jovians that is not a product of the normal Aphelion/Perihelion function, you strip away the difference by doing a complete orbit and coming back to the exact point in space and time (allowing for movement though the galaxy)to eliminate all the Aphelion/Perihelion effects. This will leave you with 2 identical semi-major axis lengths when measuring from the planet to the SSB. Then you simply look at the difference in the planet to Sun distance over those 2 time frames.
Leif Svalgaard (14:57:38) :
Here is What Shirley of JPL has to say:
What he is saying is that you can believe in correlations [as he himself does or at least did 20 years ago], but you cannot use the AM-mechanism and accelerations/decelerations and barycenters and any of that as the mechanism, if you want to stay within physical law. You have to come with something else. Angles perhaps 🙂 but not AM.
Leif Svalgaard (14:59:55) :
The Aphelion/Perihelion changes are significant at around 100,000 kilometers per week, making it very difficult to see the Sun to SSB changes which are much smaller over a week. This has hidden the semi-major axis changes that are happening from the shift in SUN to SSB distance. I think it might be an example of two different angular momentum trade off’s occurring simultaneously.
Geoff Sharp (13:58:10) :
The Aphelion/Perihelion distances are masking whats going on in the background and they need to be stripped away to see the detail. This is probably why it has not been noticed in the past.
What on earth do you mean? You’ve moved the goalposts! You described a “simple test”, and I went and worked out the answer. There wan’t anything about perihelion or aphelion distances in that test.
Geoff Sharp (06:39:06) :
There is a simple test, measure a Jovian planet’s distance to the SSB and then move forward exactly 1 orbit in time, the distance will be the same (give of take a few days) then look at the planet’s distance to the Sun on both occurrences, it will be vastly different. End of story.
I wrote: “According to my simulation model on 1 Jan 1940 the distance of Jupiter from the Sun is 7.4044526E11 m, and the distance of Jupiter from the SSB is 7.3948122E11 m. 11.85 years later takes us to early November 1951, when my simulation says the distances are 7.4027794E11 m and 7.4020631E11 m.” And when I took a look at NASA’s positions of Jupiter, and worked out the same numbers using their figures, they agreed with mine.
So, I did exactly what you said, and measured the distances. And I did it in two different ways. And the answers I got agreed with each other. And Jupiter’s distance from the SSB wasn’t the same after one orbit of 11.85 years like you said it would be. Neither was the distance to the Sun “vastly different”.
Look. There are two points. There’s position of Jupiter (xj1, yj1, zj1) and the position of the SSB (xb1, yb1, zb1) on the same date, and there’s the distance between them, d1. And 11.85 years later there are another two points, (xj2, yj2, zj2) and (xb2, yb2, zb2) and another distance between them, b2. It’s very, very simple. You said that d1 and d2 would be the same. But they’re not. And there’s nothing “masking what’s going on in the background” that needs to be “stripped away”.
Not unless your Jupiter and SSB inhabit some sort of separate reality which is inaccessible to mathematics. For this is just a mathematical problem, not a physical one. We can get these points from the NASA Horizons website without doing any physics at all.
Maybe it is indeed end of story.
Geoff Sharp (15:20:01) :
doing a complete orbit and coming back to the exact point in space and time (allowing for movement though the galaxy) to eliminate all the Aphelion/Perihelion effects.
I didn’t think one can ever come back to the same time [and what is the allowing for movement though the galaxy – how do you do that?] as a complete orbit takes ~12 years.
This will leave you with 2 identical semi-major axis lengths when measuring from the planet to the SSB. Then you simply look at the difference in the planet to Sun distance over those 2 time frames.
One can compute the semi-major axis, a, as the half the sum of the minimum and maximum distance and do this separately for a sun-centered and a SSB-centered orbit. I have done that for two complete orbits [and will do for many more when the computer is done grinding]. for the first orbit [1940+] we find
aSUN = 5.165150842 AU, aSSB = 5.158674340 AU, and for the second [1951+]
aSUN = 5.164615727 AU, aSSB = 5.160087547 AU.
Ideally the ‘real’ orbit is the one [if we want to define an orbit] with the least variation of ‘a’ with time [as the SSB moves around].
The difference between the SUN ‘a’s is dSUN = -0.000535115, and between the SSBs: sSSB = 0.001413207 or almost three times as large. The difference will not be zero as there are residual perturbations. But it seems that dSUN is the most stable…
idlex (15:43:21) :
Your completely missing my point…its not easy to get this across on here.
I am talking about using the figures off JPL to derive distances from Jupiter to SSB.
Here is my scenario again.
Take a point in time, I chose June 20 1951. Measure J distance to Sun & SSB.
Move on 1 complete orbit of J, 4339 days later we find the J to SSB distance is exactly the same as in 1951.
This date is April 7 1963. Then measure J to Sun and compare with 1951 figure. The result is .0046AU longer, this translates to roughly 700,000 kilometers.
If we also measure the Sun to SSB distance over the same timescale we get .0053AU difference which looks to be perfect. The sun doesnt return to the 1951 position in 1963 so there is some loss in the arc and the full offset is not taken up.
Do this exercise yourself (if JPL is online today) and you will quickly see my point. The Jupiter to SSB distance does not vary if we take a start and end point in the orbit as being the same (1 complete orbit, in my case 4339 days). The Jupiter to SUN distance will vary 700000 kilometers.
If you have trouble I can provide the original files I downloaded from JPL
Leif Svalgaard (15:50:27) :
Geoff Sharp (15:20:01) :
doing a complete orbit and coming back to the exact point in space and time (allowing for movement though the galaxy) to eliminate all the Aphelion/Perihelion effects.
———————————————–
I didn’t think one can ever come back to the same time [and what is the allowing for movement though the galaxy – how do you do that?] as a complete orbit takes ~12 years.
I phrased that badly, time should not have been mentioned. A better way to say it would be that Jupiter comes back to the exact point on the orbit ellipse as it was 4339 days before. The J to SSB distance is exactly the same in JPL for both of the time frames I mentioned, you dont need to calculate anything, its all in JPL.
Geoff Sharp (16:05:54) :
Move on 1 complete orbit of J, 4339 days later we find the J to SSB distance is exactly the same as in 1951.
Except that the period is 4332 days, not 4339 days…
I’m following this discussion about comparing the respective distances of the Sun & BC from J.
In a general sense, what is needed is a comparison of the 2 spreads, measured by (for example) range, IQR, variance, &/or SD.
…But that hides a lot of interesting & useful info, so better yet:
A plot of the deviations from the mean for both Sun & BC on the same plot. Both will be jumping around, but we’ll be looking to see which one is jumping around less.
With a long enough series (i.e. many J cycles – & preferably a good number of U-N cycles or a whole 2402 year cycle), there won’t be any need to worry about seasonal/elliptic/epitrochoid confounding obscuring our view.
Geoff Sharp (16:05:54) :
Take a point in time, I chose June 20 1951. Measure J distance to Sun & SSB. Move on 1 complete orbit of J, 4339 days later we find the J to SSB distance is exactly the same as in 1951.
this is where your selection effect comes into play. You look for a time where the distance is the same and then wishfully assert that that is a complete orbit 4339 days. It is not, because the SSB has moved in the mean time. The orbital period is 4332 days. Since you define a full orbit as the time from a given distance to the same distance no wonder that the distance doesn’t vary. This is wrong. But it all doesn’t matter because it is irrelevant. The AM is what it is without making any assumption or test of what orbits what, and there is complete balance between what the Sun has and the planets have, so no going back and forth between them and changes to rotation periods or anything. Take it from the reformed sinner [Shirley] from JPL http://www.leif.org/research/Spin-Orbit-Coupling-Shirley-JPL.pdf and learn from him if you don’t want to learn from us. There is no spin-orbit coupling and it doesn’t matter what orbits what. Let not the progress we have all achieved here slide back into obscurantism again. Real progress has been made, one branch has been lopped off, and you can blaze a new trail down another branch [tides, General Relativity, gravitomagnetism (you’ll have lots of fellow travelers on that one].
I just read the Shirley (2006) paper to which Leif referred. [See Leif Svalgaard (14:57:38).] That was a constructive exercise.
My sense of “something fishy” (from reading the abstract) was warranted.
No attempt is made in the article to address rotation, let alone differential rotation. The treatment is too simplistic and surely will not be the final influence on our thinking.
And before there is any opportunistic distortion: I am not arguing for spin-orbit coupling.
Also noteworthy: It was interesting to see an error in De Jager & Versteegh (2005) pointed out.
Geoff Sharp:
I am talking about using the figures off JPL to derive distances from Jupiter to SSB.
Let me stop you right there and ask you what you mean by “the figures off JPL”. Earlier today I went to the NASA Horizons website and asked for this::
Ephemeris Type [change] : VECTORS
Target Body [change] : Jupiter [599]
Coordinate Origin [change] : Solar System Barycenter (SSB) [500@0]
Time Span [change] : Start=1940-Jan-01 00:00:00.0000, Stop=1940-Jan-15 00:00:00.0000, Step=1 d
Table Settings [change] : output units=KM-S; quantities code=2
Display/Output [change] : default (formatted HTML)
This is exactly what I did. What exactly did you do to get “the figures off JPL”?
I’ll return to the matter tomorrow, if I have time, and pursue you step by step the rest of the way.