I have gathered together my sources and citations that explain accelerated surfaces in General Relativity and placed them into one thread for Diving Insight to refute if he wishes. He has yet to provide any sources or citations showing his understanding is valid. His personal opinions show evidently he does not understand what he claims.Divine Insight wrote:
I have reason to be concerned.
Here you are starting an entire sub-forum on science and you believe that General Relativity is stating that the Earth Surface is accelerating outward at 9.8 m/s/s.
That is simple false. And if you go around teaching people that this is what General Relativity is saying then you are perpetuating false information.
General Relativity is NOT describing the Earth's surface to be accelerating up toward us.
Here you are starting a Science sub-forum and you don't even understand the basics of modern science.
You better get that squared away first.
He can then feel free to apologize for his unnecessary concern and claims of propagating false information, which in fact is what he is doing.
"The key idea of general relativity, called the equivalence principle, is that gravity pulling in one direction is completely equivalent to an acceleration in the opposite direction. A car accelerating forwards feels just like sideways gravity pushing you back against your seat. An elevator accelerating upwards feels just like gravity pushing you into the floor."
http://www.pbs.org/wgbh/nova/physics/re ... osmos.html
"He proposed an experiment involving two elevators: one at rest on the ground on the Earth and another, far out in space away from any planet, moon, or star, accelerating upward with an acceleration equal to that of one Earth gravity (9.8 meters/second2). (Modern readers can substitute ``rocket ship'' for Einstein's elevator.)
"The equivalence principle was Einstein's `Newton's apple' insight to gravitation. His thought experiment was the following, imagine two elevators, one at rest of the Earth's surface, one accelerating in space. To an observer inside the elevator (no windows) there is no physical experiment that he/she could perform to differentiate between the two scenarios.
The equivalence principle is a fundamental law of physics that states that gravitational and inertial forces are of a similar nature and often indistinguishable."
http://abyss.uoregon.edu/~js/21st_centu ... lec07.html
"In a gravitational field (of small spatial extension) things behave as they do in a space free of gravitation, if one introduces into it, in place of an â€œinertial systemâ€�, a frame of reference accelerated relative to the former.
Inertia and gravity are phenomena identical in nature. From this and from the special theory of relativity it follows necessarily that the symmetric fundamental [metric] tensor gmn determines the metric properties of space, the inertial behavior of bodies in this space, as well as the gravitational effects."
http://www.sciforums.com/showthread.php ... -s-surfaceIf the ground wasn't there (e.g. all the Earth's mass was concentrated at the Earth's centre instead), then you'd free-fall towards the centre of the Earth. To stop that from happening, the ground exerts an upwards force on you.
Now, in general relativity, you need to realise that gravity is not a force. Gravity is just spacetime geometry. So, as you stand on the surface of the Earth,the only force acting on you is the ground pushing up. There's no "gravity pulling you down" force.
Newton's second law says F=ma . That is, you accelerate in the direction of the net force on you.* And when the only force is the ground pushing up, that means you must be accelerating upwards as you stand on the Earth's surface.
Here's another forum with working physicists that say the same thing...
http://www.physicsforums.com/archive/in ... 60253.htmlIn Newton's theory, a falling object is accelerating at 9.8 m/s2 in the "down" direction. In GR, the surface of the Earth is accelerating 9.8 m/s2 in the "up" direction
"The 1 g-force on an object sitting on the Earth's surface is caused by mechanical force exerted in the upward direction by the ground, keeping the object from going into free-fall. The upward force from the ground ensures that an object at rest on the Earth's surface is accelerating relative to the free-fall condition, which is the path that the object would follow when falling freely toward the Earth's center.
While acceleration is a vector quantity, g-force accelerations ("g-forces" for short) are often expressed as a scalar, with positive g-forces pointing upward (indicating upward acceleration), and negative g-forces pointing downward. Thus, a g-force is a vector acceleration. It is an acceleration that must be produced by a mechanical force, and cannot be produced by simple gravitation. Objects acted upon by only by gravitation, experience (or "feel") no g-force, and are weightless."
"The Principle of Equivalence says that we can base our calculation on the assumption that the Earthâ€™s surface is accelerating upward...
http://www.alternativephysics.org/book/ ... tivity.htm