I have read through this article and must conclude that it is of GA standards. It is well written, exhaustively referenced, and contains content of vital importance. Though the article is perhaps over long, it is clear that much effort has gone into it. It is my opinion that it should be listed as a Good Article. J.T Pearson (talk) 13:00, 18 July 2008 (UTC)
The various equations surrounding force abound. To say that gravity is a force requires one to verify that gravity can be substituted for a force in all the equations. The problem is, you can't. It simply doesn't hold, despite Wikipedia's article on force which contends otherwise.
It boils down to this (ie, the following statements, as stated, are true):
1. All bodies in non-gravitational free-fall which experience a force experience a correlating acceleration which is equal to the ratio between the force and the mass.
That acceleration can be measured by an on-board accelerometer.
2. All bodies in free-fall experiencing a change in their velocity relative to a neighboring massive object (such as the Earth) appear to be accelerating in a direction parallel to the line between the body's center of mass and the object's center of mass.
That acceleration can NOT be measured by an on-board accelerometer.
The point is that regardless of the differences between gravity and traditional forces, there is a difference. It's that difference which sets gravity apart from a force.
Gravity is not a force. It's a warping of the space-time in which all affected matter and energy exist, as both matter and energy are affected by gravity.
Consider Newton's First Law: "A particle will stay at rest or continue at a constant velocity unless acted upon by an external unbalanced force." Thus, a planet will continue in a straight line unless acted upon by a force.
But is gravity really a force? No. Gravity simply warps space-time in the solar system such that a planet's orbit really is a straight line. All on-board accelerometers can measure any force enacted upon a free-falling body. No on-board accelerometer can measure the effect of gravity upon a free-falling body. Thus, gravity is not a force. —Preceding unsigned comment added by 87.177.21.106 (talk) 19:27, 27 July 2008 (UTC)