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  Looking for solid information about characteristics gravitational field effects

+ 0 like - 3 dislike

first maybe I should start with... is the quote from this site accurate? (quote follows link)
"The same dilemma comes up in many guises: Why do photons from the Sun travel in directions that are not parallel to the direction of Earth’s gravitational acceleration toward the Sun? Why do total eclipses of the Sun by the Moon reach maximum eclipse about 40 seconds before the Sun and Moon’s gravitational forces align?" 

If the described events do happen and indicate a faster than light speed for gravitational acceleration...


Second; the area of a containing mass is not mentioned (density of a thing), so if a mass equivalent to earth was felt at the distance of the moon, but instead of being in 1.08e+12 km^3(what it is) was actually in 2.38e+17 km^3 (radius of distance to moon) wouldn't that be the same acceleration?  ( earth's density 5.51 g/cm³  or 5.51e+12 kg/km^3; atmosphere density at sea level 1.225e+9 kg/km^3; ... which is only 1000 different so the resulting volume would be very roughly another 100 less dense than air )

So if a very distant star explodes, other than the small amount of matter converted to energy, isn't the overall mass of that area going to be the same effect?  So why would they presume that LISA could measure such events as gravitational waves?   http://lisa.nasa.gov/ (LISA) or LIGO https://en.wikipedia.org/wiki/LIGO

asked Jan 3, 2016 in Experimental Physics by d3x0r (-15 points) [ revision history ]
edited Jan 9, 2016 by d3x0r

Hmmm.  According to Wikipedia  the author : "The Thomas C Van Flandern (June 26, 1940 – January 9, 2009) was an American astronomer and author specializing in celestial mechanics. Van Flandern had a career as a professional scientist, but was noted as an outspoken proponent of non-mainstream views related to astronomy, physics, and extra-terrestrial life. He also published the non-mainstream Meta Research Bulletin"

A mainstream  explanation for the observation  is given here : "Strictly speaking, gravity is not a "force" in general relativity, and a description in terms of speed and direction can be tricky.  For weak fields, though, one can describe the theory in a sort of newtonian language.  In that case, one finds that the "force" in GR is not quite central—it does not point directly towards the source of the gravitational field—and that it depends on velocity as well as position.  The net result is that the effect of propagation delay is almost exactly cancelled, and general relativity very nearly reproduces the newtonian result."

I love that on can ask a reasonable question that isn't a duplicate (yes I did search first), and get negative votes :)

Okay; So I suppose that the distortion exists perpetually, so it doesn't really propagate...although the creation/destruction of such a spacial distortion would propagate?  And the next step would then be does the same rule apply for magnetic fields?  Such that if I have a magnet spinning, does the attractive/repulsive force lag according to it's actual position?  Since the field already exists, it won't have a propagation delay.

I would be more interested in the GR theory that cancels out the effect... I remember reading a paper to that effect but I don't remember what or where it was.  I mean light travels at the speed of light, but it definitely travels at the speed of light, it's not instantaneous like the gravitational acceleration.  (Yes it's not a force since force = mass * acceleration and mass is irrelevant as illustrated by hammer(bowling ball)/feather drop in a vacuum indicates) 

Also, I tried to do some searching for 'when gravity isn't towards the center of gravity at a velocity' but didn't find any such information, need more input.

I think you're getting downvotes because Physics Overflow is supposed to be "graduate level" questions, and it's "undergraduate level" knowledge that e.g. gravitation is not instantaneous in general relativity. Physics Forums or Physics Stack Exchange are more suited to that level of discussion. 

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