Originally posted by @moonbus doesn't pull evenly everywhere on the planet. As the article linked below explains, it can affect measuring instruments and have long-term political consequences
"'Gravity doesn't pull evenly everywhere on the planet" isn't any surprise at all. It isn't any news, this has been known for long. It differs from the equator to the poles, it differs between different elevations, it differs over ore deposits, and more. It doesn't change an objects mass, only its weight.
It can have long-term political consequences? How?
Originally posted by @moonbus The Mason-Dixon line, for example.
Tell me what the Mason-Dixon line has to do with gravity? Politics sure, but gravity?
Long term politics like having control over avalanches? Mudslides, glacier speed? What?
General talking to his troops. Ok, leathernecks, we have control over that glacier speed and we are going to run it up 100 times faster, that military base at the bottom of the mountain will be history in 10 days, THEN we attack........
The border between Pennsylvania and its immediate neighbors, Maryland and W. Virginia was in dispute, about 4,000 sq. miles of territory were at stake. Current maps were inaccurate. So a more accurate survey was commissioned.
It made a great deal of difference to certain people, whether they were born on one side of the boundary or the other. Anyone born on the Pennsylvania side was born free; certain people born on the other side were born into slavery. I guess one could call that a political issue, since the country went to war over it a hundred years later.
What has gravity to do with the Mason-Dixon Line? Mason and Dixon were using a telescope to sight stars in order to determine latitudes and longitudes. To get an accurate fix on a star, the telescope had to be pointed at a known angle. To get the telescope pointed at a known angle, a plumb bob was used to determine the vertical as a reference point. One tends to assume that a plumb bob will always point straight down; not so. The lead weight was pulled off true vertical by massive bodies in the vicinity (e.g., mountain ranges), thus skewing the angle of the telescope and distorting the measurements, in places by as much as 900 feet. Mind you, Mason and Dixon could not have known this; they did exemplary work given the level of knowledge and technology available to them. Still, …
… suppose someone was born in that zone of error during the hundred years between the laying down of the markers and the Emancipation Proclamation; it could have made a freeman into a slave, or v.v, depending on which way the error ran.
Originally posted by @moonbus What has gravity to do with the Mason-Dixon Line? Mason and Dixon were using a telescope to sight stars in order to determine latitudes and longitudes. To get an accurate fix on a star, the telescope had to be pointed at a known angle. To get the telescope pointed at a known angle, a plumb bob was used to determine the vertical as a reference point. One ten ...[text shortened]... own this; they did exemplary work given the level of knowledge and technology available to them.
As I said earlier: It has nothing to do with gravity - more like lack of knowledge at those times.
Originally posted by @ogb almost all of gravity is in another dimension. which proves string theory is correct.
How do you know that? The ongoing tests of the inverse square law at closer and closer distances have gotten now to about 100 microns apart of test masses with no variation from inverse square, which is not to say getting even closer will show variations which would be taken as indications of interference with gravity by extra curled up dimensions but so far nuttin. It gets very tedious to make accurate readings to verify inverse square when distances go less than 100 microns separation of the test masses. Not sure why exactly but that is what the papers I read indicated.