A pdf copy of Ian Wilson's talk to the Lavoisier Group AGM (11th July 2008) in Melbourne, Australia, is posted at:
http://www.lavoisier.com.au/papers/articles/IanwilsonForum2008.pdf
Ian Wilson was born in Ipswich , QLD, in 1955. He graduated in physics from the UNE in 1977 and obtained his PhD in astronomy in 1982 from the ANU, having worked at the Mt. Stromlo & Siding Spring Observatories.
He was subsequently a Junior Research Fellow at the Royal Greenwich Observatory, a Research Fellow at Harvard, Ass. Professor at the Universities of Toledo and Oklahoma , and Operations Astronomer at the Hubble Space Institute in Baltimore MD.
Since 1995 he has taught science and mathematics in Queensland and is now teaching in Toowoomba.
For those that are interested, you might want to have a look at a scientific article whichactualy backs my position:
"Impact of variations in solar activity on variations on hydrological decadal patterns in Northern Italy". by Zanchettin et al. Jounal of Geophysical Research, 2008, Vol 113, D12102.
http://adsabs.harvard.edu/abs/2008JGRD..11312102Z
Arnost said..."If all the planets were aligned on the same side of the Sun, the combined center of mass would lie about 500,000 km above the Sun's surface".
Thanks for reply, Arnost. I have a pretty decent understanding of CM from engineering math (washer regions, etc.)and binary stars in astrophysics. I also know that CM has a significance, but in the case of all the planets lining up on one side of the Sun, we've approached that haven't we? Don't you think a CM at 500,000 km would create a distinct wobble?
I'm reminded of Mark Twain's humour with regard to the Mississipi River. As you know, it's a meandering river and is subject to shortening as ox-bows in the river are breached by floods. Twain said:
"In the space of one hundred and seventy six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over a mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oölitic Silurian Period, just a million years ago next November, the Lower Mississippi was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-pole. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo [Illinois] and New Orleans will have joined their streets together and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact".
I like his comment at the end about science:
"One gets such wholesale returns of conjecture out of such a trifling investment of fact".
Ian Wilson...don't worry about it, I didn't take any offense.
I don't have anywhere near the qualifications you have and I wasn't trying to infer you are wrong. I was merely questioning something that didn't make sense to me. That wouldn't be the first time either. I usually speak up when something doesn't seem right to me. I have the habit of raising questions by making inferences, a quality that doesn't appeal to many people, and is often misunderstood.
Arnost,
My 2009 Russian paper tries to explain why there might be an apparent conection between the motion of the Sun about the Barycentre of the Solar System and the Earth's rotation.
I assert that there is no physical connection between the two phenomena. They just appear to related to each other because each shares a common driving mechanism.
The motion of the Sun about the Barycentre is just a reflection combined gravitational effects of the Jovian planets upon the Sun.
Hence, the synchronization that we observe between the Sun motion and the Earth's rotation suggest that phenomenon that is driving the changes in the Earth's rotation must be synchronized with the motion of the Jovian planets (unlikley as this may be).
The only reasonable explanation that I could come up with goes roughly along these lines:
[before anyone jumps on this explanation please realize that I beieve that this is NOT the only possible explanation].
"We know that the strongest planetary tidal forces acting on the lunar orbit come from the planets Venus, Mars and Jupiter. In addition, we known that, over the last 4.6 billion years, the Moon has slowly receded from the Earth. During the course of this lunar recession, there have been times when the orbital periods of Venus, Mars and Jupiter have been in resonance(s) with the precession rate for the line-of-nodes the lunar orbit. When these resonances have occurred, they would have greatly amplified the effects of the planetary tidal forces upon the lunar orbit. Hence, the observed synchronization between the precession rate of the line-of-nodes of the lunar orbit and the orbital periods of Venus, Earth, Mars and Jupiter, could simply be a cumulative fossil record left behind by these historical resonances."
"At first glance, there does not appear to be an obvious physical phenomenon that would link the Sun’s motion about the Solar System’s CM to the Earth’s rotation rate. However, such a link could occur if the rate of precession of the line-of-nodes of the Moon’s orbit were synchronized with orbital periods of Terrestrial planets and Jupiter, which in turn would have to be synchronized with the orbital periods of the three remaining Jovian planets. In this case, the orbital periods of the Jovian planets, which cause the asymmetries in the Sun’s motion about the CM, would be synchronized with a phenomenon that is known to cause variations in the Earth’s rotation rate, namely the long term lunar tides."
Gordon Robertson,
I am deeply sorry for lashing out at you in my post. I apologise for what I said.
I misunderstood your original post and my words were those of someone who was tired and dispirated. The words I used were unexcusable and I wish that I could withdraw them.
I am very tired right now but I will try to answer your questions in a day or so.
Gordon, thanks for the replies…
This is my take on things:
Any two gravitationally bound bodies ALWAYS orbit around the combined centre of mass of the entire system – the barycentre. If two orbiting bodies are of the same mass, the centre of mass will be half way between the two. If the bodies differ in mass, the centre of mass may be within the larger. See the following orbital representations:
http://en.wikipedia.org/wiki/Center_of_mass#Animations
The solar system is a multi-body system. If the planets are evenly distributed around the sun, the combined centre of mass would be deep within the sun. If all the planets were aligned on the same side of the Sun, the combined center of mass would lie about 500,000 km above the Sun's surface. This is a representation of the position of the solar barycentre with respect to the centre of the sun:
http://i173.photobucket.com/albums/w45/CarlSmith_2007/Sun%20SSB/ssb-orbit-col.gif
And every day is a slightly different length by a few microseconds – sometimes longer, and sometimes shorter – and this is measured as the Length-of Day (LOD).
http://geology.about.com/od/tectonicsdeepearth/a/lodresearch.htm
Variations of the atmospheric angular momentum (the AAM) is thought to be responsible for almost all of the LOD variation on time scales from several days to several years. The variations in ENSO and Quasi-Biennial Oscillation (QBO) phases drive the AAM and so can explain LOD variations. Google [QBO ENSO LOD]…
Now Ian tells us that the suns wobbles around the solar system barycentre and the earths LOD are correlated… Hmmm… IF there is a CAUSAL correlation, I’m pretty much well of the opinion that gravity will have very little to do with this. Even though the Jovian planets are pretty massive, because gravity follows the inverse square law, their influence on the sun will be quite low… Venus probably will have a larger gravitational effect on the Sun than Jupiter (or at least Saturn). So what else is there…?
Arnost said "Three types of torque operate between the solid Earth and its fluid envelope (the atmosphere and oceans): pressure, gravitational and frictional torques".
Arnost...thanks for explanation. If you draw a freebody diagram of the Earths as it rotates on it's axis and revolves in it's orbit, there are only two significant forces on it. One is the gravitational force from the Sun and the other is the gravitational force of the Moon.
Even though the Moon causes the oceans to rise on Earth due to it's gravitatiojnal effect on us, it does not slow the Earth's angular velocity. Neither does the G-force from the Sun. The Earth will continue to spin at its current velocity because there is no external force acting on it tangentially.
I am aware of the forces you talk about, that act internally, but they do not affect rotational speed or orbital speed. If they did, the Earth would be slowing down and speeding up in both. The angular velocity of the Earth's rotation is constant because there are no external frictional forces acting on it. If there was, it would slow down.
The atmosphere and oceans travel with the Earth because they are bound to it by gravity. The Earth is not moving through them. Any torques occuring within the system are not going to affect the system itself in it's rotation or it's orbit. If you were turning on a merry-go-round, you could press as hard as you want against the device, in a direction opposite it's rotation, and nothing would happen.
The merry-go-round slows eventually due to friction in its bearings and wind resistance from the atmosphere. But it is turning 'in' the atmosphere, the Earth is not. Think about it for a minute. The Earth's angular velocty is about 1000 miles per hour at the equator. If the Earth was traveling through the atmosphere, we'd be faced with a 1000 mile per hour wind. We feel no wind from that rotation. Wind comes from differences in heat potentials, an internal process.
Linear momentum is defined as a mass times a velocity. Newton tells us that a body at rest will remain at rest unless acted on by a force. Conversely, a body in motion will remain in motion until acted on by a force. If the torques you mention were significant, the Earth would be wobbling, but nothing will change it's momentum till you apply an external force to change either the angular velocity of it's rotation or the velocity of it's orbit.
Take for example a child's toy that is a sphere with marbles in it. If you roll the ball, the torques from the marbles moving inside may cause the ball to rotate sideways, but it is the friction on the floor that causes it to slow down. If that ball was moving through a frictionless space, it would never slow down unless another force acted on it. The internal torques don't reduce the momentum.
Ian Wilson said "No offense, but can I suggest that you enrol in a high school physics course. Most high school physics students woud have no trouble recognising the the flaws in your arguements".
I was thoroughly trained in the basics of physics as an undergraduate engineer (applied science). If you have any problem with what I have said, I think you should be specific. I'm beginning to wonder if you haven't gotten yourself caught in a theoretical void.
Engineers can't mess around with theoretical physics and rely largely on Newtonian Mechanics. Orbital motion can be perfectly explained by Newtonian Mechanics, but there are theories in theoretical physics that are so far out I doubt if they will ever find proofs.
David Bohm was a theoretical physicist admired by Einstein. Bohm tried to integrate the human mind into physics and had long dialogs with Jiddu Krishnamurti. I recall Bohm claiming once that Newtonian Mechanics and Quantum Mechanics were parallel to each other and that each had come to an end.
He thought the problem was our dependence on the parameter of time, and that we would have to re-examine phenomenon with a new parameter that will have to be discovered. When Newton devised his second law, he thought time was an absolute quantity, but Einstein proved that wrong. Bohm seems to have been saying that we need the exact relationship between force and mass, that causes it to accelerate, and is responsible for momentum and inertia, rather than the artifical man-made parameter of time.
Arnost tried to come to my defence by claiming "Gordon, I think that Ian is NOT talking about the Earth's ORBITAL variations, but rather, its ROTATIONAL variations....".
Thanks Arnost. I am perfectly aware of what Ian is saying, but he has made a claim that the Sun is moved away from the Solar System's centre of mass (CM) by the gravitational pull of the Jovian planets. I asked him what happened to Kepler's laws, but instead of answering the question, he advised me to get a course in physics.
When I studied astrophysics as a minor, we had to calculate the orbital period of the Earth based on it's mass and Kepler's laws. There were no parameters added for the gravitational effects of the Jovian planets, presumably because their gravitational effect is minimal. If I want to calculate the Earth's period about the Sun (~365 1/4 days)I don't need to include the effects of the Jovian planets on the Earth, so why should they influence a much larger mass like the Sun?
I'd like Ian to explain why a Ph.D in astrophysics taught me that, yet he claims I don't understand physics.
My compliments to you Ian for an excellent presentation. Gavin is just trying to muddy the waters, again.
One point that jumped out in the discussion of the 150km wide oceanic bands with variations in sea level was where these bands sat in relation to the 12 Pacific Ocean measurement stations that CSIRO claim to show significant sea level rise over the past half century.
For a start this sample is no-where near adequate, is highly contaminated by coral subsidence and is not evenly distributed. So is there any chance of doing an overlay to determine if these bands are also influencing the result?
Ian: this new concept of yours is hard to swallow on other grounds. The thermal lag after warming - cooling cycles every 12 hours has not been accounted for yet (a least to my satisfaction).
I guess the real question is, how does it go down with your peers in the long run?