One of the first tests of Einstein’s theory of general relativity was to explain the precession of the perihelion of Mercury, which had long bamboozled astronomers. Newton’s law of gravity simply cannot account for it. But relativity does.
Now it’s Saturn’s turn to flummox astrophysicists. The Russian astronomer Elean Pitjeva, who heads the Laboratory of Ephemeris Astronomy at the Institute of Applied Astronomy in St Petersburg, has analysed a huge data set of planetary observations dating back to 1913, including 3D observations of the Cassini spacecraft now orbiting Saturn.
She says that the precession of Saturn’s perihileon, as predicted by general relativity, needs to be corrected to fit the data. The correction is tiny: -0.006 arcseconds per century.
That’s an astonishing claim but perhaps not surprising given the growing body of evidence that some kind of correction to gravity is needed to explain various puzzling phenomena such as the Pioneer and Flyby anomalies.
Obviously Pitjeva’s work needs to be independently verified but already the astronomy-mill is hard at work guessing what might cause the deviation from Einsteinian physics.
It’s possible that known physics will do the trick: for example, our knowledge of trans-neptunian objects may have enough uncertainty to allow for this kind of correction.
Lorenzo Iorio at the National Institute of Nuclear Physics in Pisa Italy, outlines various explanations of known physics:
Our knowledge of trans-neptunian objects may have enough uncertainty to allow for this kind of correction but this turns out to generate a prograde precession no the retrograde precession found by Pitjeva
The Lense-Thirring effect generates a force that is four orders of magnitude too small to account for the difference
Mutual cancellations among unmodelled or mismodelled effects may have conspired to cause the effect but Iorio says this looks exceedingly unlikely
Neither do various exotic modifications of gravity or the DGP braneworld model explain the figures, says Iorio
So what’s left? A magnificent conundrum for astronomers to puzzle over until they get better data and/or a new theory of gravity that explains all.
Ref: arxiv.org/abs/0811.0756: On the Recently Determined Anomalous Perihelion Precession of Saturn
I’ve heard rumors that the Goedel’s cosmology (rotating universe) could explain the Pioneer anomaly. Has anyone looked into applying Goedel’s cosmology to the Saturn precession?
Or maybe the data was miss-analysed. What are the statistical & systematic uncertainties from using data dating back to 1913?
Or maybe the Saturn hexagon is a living creature and actively keeping its pure-water fresnel rings pointing at the home system. This seems like the simplest explanation.
Wait, wasn’t the flyby anomaly explained by special relativity?
http://arxivblog.com/?p=629
So surely that couldn’t be supporting evidence for modifying general relativity.
Or maybe Logunov’s theory could give us the explanation for this unexpected result, only God knows it.
One of the first tests of Einstein’s theory of general relativity was to explain the precession of the perihelion of Mercury, which had long bamboozled astronomers. Newton’s law of gravity simply cannot account for it. But relativity does.
It is so comforting to read this mythology repeated once again in the blogosphere. This is like claiming that the theory of Zeus explained lightning. It’s comfortingly cargo science but wrong anyhow.
“Newton’s law of gravity simply cannot account for it” is one of the biggest lies ever told by physicists. If you take a look at LeVerrier’s computations you will see that he is not using Newton’s theory of gravity. He is simply using trigonometric methods to fit observations.
And is it really the general relativity that explained Mercury’s perihelion or is it the good old equation of the ellipse with an addition of ad hoc term? The truth is, the latter.
The writer of this blog post obviously is a marketing person who is repeating the standard physics puns and tropes as if they were absolute truths. Poor physics has been turned into a cargo cult in the hands of post Einsteinian physicists and their collaborators in the media.
When Iorio writes that this effect “can be explained neither by any of the standard classical and general relativistic dynamical effects mismodelled/unmodelled in the force models of the EPM2008 ephemerides nor by several exotic modifications of gravity recently put forth to accommodate certain cosmological/astrophysical observations without resorting to dark energy/dark matter” he is using the same kind of trick where he names some coefficients in his fits to be general relativistic on totally arbitrary grounds. The tradition continues.
According to the Iorio’s paper, Pitjeva obtained a formal, statistical error of 0.0007 arcseconds/century, while the realistic one is 0.002 arcseconds/century, i.e. three times larger.
Aliens have been observing our Earth for a long time.
Now soon they are about to be detected.
Can it be their huge ship that causes these anomalies?