Tom Van Flandern (1940-2009) was a free-thinking physicist who with perplexion made the observation (along with Laplace and also Newton of course) that the Earth on its path around the Sun at every instant in time accelerates in the direction of the actual position of the Sun, which is about 20 arc seconds ahead of the position of the Sun as seen in the sky from the Earth, because of the 8 minutes it takes for light to travel the distance from the Sun to the Earth. See also this review of Van Flandern’s work.
This observation is in accordance with Newtonian gravitation, which is assumed to propagate with infinite speed. If gravitation propagated with the speed of light, the acceleration would be instead in the direction of the visible Sun, but this is not what is observed (because it would be unstable).
I have discussed this observation in various posts with conclusion that the connection between mass density $\rho (x,t)$ and gravitational potential $\phi (x,t)$ as given by Poisson's equation in Newtonian gravitation
- $\Delta\phi (x,t)=\rho (x,t)$
with $\Delta$ the Laplacian with respect to a space coordinate $x$ and $t$ being a time coordinate, is to be interpreted as a relation where mass $\rho (x,t)$ somehow is "created" at $x$ at time $t$ by the local operation of differentiation through the Laplacian $\Delta$ acting on the gravitational potential $\phi (x,t)$.
This is different from the standard interpretation where instead the presence of mass $\rho (x,t)$ at a specific point in space at time $t$ contributes to $\phi (x,t)$ for all points $x$ somehow through instant action at distance. Like Tom Van Flandern I view instant action at distance as physically impossible, while local instant action may be physical. The creation of mass from gravitational potential through the Laplacian thus may be possible, while its detailed physics remains to be discovered...
In any case the observation of the acceleration of the Earth towards the actual position of the Sun is only compatible with a speed of propagation of gravitational waves (if they exist), which is much bigger than the speed of light. This observation is in accordance with Newton's mechanics (with both the new and old interpretations of the mass-potential connection), but not with Einstein's mechanics.
What is your conclusion concerning who describes physics of gravitation best? Newton or Einstein? Be careful when you look at the Sun for answer.
The current wisdom among physicists is that despite the above Earth-Sun observation, for sure there are gravitational waves because Einsteins so says, waves which propagate with the speed of light and that these waves can be detected, not gravitational waves from the Sun, but from distant mergers of black holes and stuff. Do you buy this?
Sorry to say Tom passed away in 2009, but his ideas live.
PS Of course there is a cover up suggesting that also in Einstein's mechanics does the Earth accelerate in the direction of the current position of the Sun, even if the speed of gravitational waves is the finite speed of light, because there is a subtle cancellation of the effect of the 8 minute delay from another effect, a most happy and welcome cancellation which allows a stable observable planetary system not only according to Newton but also for Einstein. But why Einstein if Newton explains what is observed? No wonder that Einstein begged for pardon in his: "Newton, forgive me!".
What is your conclusion concerning who describes physics of gravitation best? Newton or Einstein? Be careful when you look at the Sun for answer.
The current wisdom among physicists is that despite the above Earth-Sun observation, for sure there are gravitational waves because Einsteins so says, waves which propagate with the speed of light and that these waves can be detected, not gravitational waves from the Sun, but from distant mergers of black holes and stuff. Do you buy this?
Sorry to say Tom passed away in 2009, but his ideas live.
PS Of course there is a cover up suggesting that also in Einstein's mechanics does the Earth accelerate in the direction of the current position of the Sun, even if the speed of gravitational waves is the finite speed of light, because there is a subtle cancellation of the effect of the 8 minute delay from another effect, a most happy and welcome cancellation which allows a stable observable planetary system not only according to Newton but also for Einstein. But why Einstein if Newton explains what is observed? No wonder that Einstein begged for pardon in his: "Newton, forgive me!".
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Claes, what if the gravitational waves detected in LIGO provide a clue to this?
SvaraRaderaPerhaps, as the sun translates through space it 'plows' a 'furrow', a gravitational wave. The spin of the sun (frame dragging) causes this gravitational wave to be in the form of a spiral away from the sun, and the planets 'ride' in this 'furrow'.
Sort of like this:
https://www.storyblocks.com/video/stock/gravitational-waves-or-gravity-waves-formed-by-two-orbiting-stars-visualization-animation-version-6-sc_gkktfiru7dhfc
... but with only one star. You'll note each star has a 'furrow' behind it. If that's the case, then so does our star, and I'd bet that frame-dragging and translational movement causes that 'furrow' to trail along behind and expand outward from the sun. And I'd bet the planets ride along in this 'furrow'.
So before we state anything about 'instantaneous' this or 'action at a distance' that, we should look out into space and see if we can see any planets which are:
1) accelerating toward a position ahead of the actual position of the star at the time differential between star and planet;
2) accelerating toward a position behind the actual position of the star at the time differential between star and planet;
3) accelerating toward a position exactly equal to the actual position of the star at the time differential between star and planet.
It may be that the planets in our solar system have a combination of translational movement and solar spin such that the earth just appears to be accelerating toward the actual position of the sun given the time differential between star and planet, but that slower or faster spinning, or slower or faster translating stars cause the planets to accelerate toward a different point as they ride that gravitational wave 'furrow' emanating from the sun.
Imagine one of those coin wells, where you put a coin on the outer edge and roll it, it rolls around and around, always descending toward the hole in the center.
SvaraRaderaNow, image the hole is the sun and the coin is a planet. And imagine the coin well is the geodesics of space-time, with a 'furrow', a gravitational wave, spiraling out away from and behind the sun due to frame-dragging by the spin of the sun. Of course, there's no friction in space, so the rolling of the planetary 'coins' around the sun's 'coin well' goes on for a very long time.
It would stand to reason that the planets would follow this 'furrow', arcing at the same rate as the sun arcs in its transit around the black hole at the center of our galaxy because the sun's 'coin well' is similarly arced.
Thus, the planets would always accelerate toward the direction the sun is moving, because the geodesics of space-time have been 'warped' into an arc around the black hole at the center of our galaxy by the sun's transit through that space-time.
So the black hole at the center of our galaxy is one 'coin well' which the sun rolls around, the sun itself is the 'coin well' which the planets roll around. The sun's 'coin well' is arced due to interacting with the black hole's 'coin well'.
I lack the mathematical ability to model this, alas.
Claes, would it be correct to say that the planets have elliptical orbits with the perihelion of the orbit diametrically opposite to the position of the black hole at the center of our galazy, and the aphelion closest to the position of the black hole at the center of our galaxy?
SvaraRaderaWould that account for apsidal precession, given that the sun orbits the black hole at the center of our galaxy, and the planets must account for this change in the geodesics of space-time by precessing their orbits?
https://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Precessing_Kepler_orbit_280frames_e0.6_smaller.gif/280px-Precessing_Kepler_orbit_280frames_e0.6_smaller.gif
So what I'm trying to say in the animated GIF above as regards apsidal precession...
SvaraRaderaImagine an arrow constantly pointing from the star toward the aphelion of the planet's orbit (the longest distance between sun and planet)... that would point toward the black hole at the center of our galaxy.
Imagine an arrow starting at the star and at a 90 degree angle to the first arrow (at first, pointing straight down, rotating counterclockwise as the image iterates) which would indicate the direction of motion of the star.
Thus, as the star moves, the planet's orbit must precess to account for the change in the geodesics of space-time due to the gravitational pull of the black hole at the center of our galaxy.
Or am I completely off-base here?