The Gravity Cannon Experiment

The Gravity Cannon Experiment is a simple test that could be conducted in Earth’s orbit that would easily verify the Equivalence Principle. The main advantage of this test over other experimental verifications of the Equivalence Principle is that it can be used to differentiate between the various physical theories used to explain the nature of gravity. While most competing theories of gravity tend to predict the same results for gravity experiments, this experiment would yield quite different results depending on which theory is correct.

Not only would the gravity cannon test differentiate between competing theories of gravity, it would probe the Equivalence Principle to the deepest level of its meaning.

Gravity theories tend to fall into four distinct groups: attraction theories, mathematical theories, pushing gravity theories and empirical gravity theories.

In attraction theories, an attractive force is exerted between bodies across vast distances of space. Newton’s theory of Universal Gravitation is an example of an attraction theory that views gravity as a metaphysical bond between all matter and as such does not require a physical mechanism to make it work.

In mathematical theories, complex geometric equations are crafted to coincide with measurements of gravitational motion. Einstein’s theory of General Relativity is an example of a mathematical theory. Whereas Newton was unable to offer any mechanism by which his “action at a distance” could operate, Einstein proposed that the mass of bodies caused the space and time around them to move in a non-intuitive way that could only be described as a curvature. This curved space and time resulted in the apparent attraction between bodies of matter. In Newton’s system, bodies of matter move through an inert space as a defintion for a constant time. The Equivalence Principle is not required by the system and appears merely as a curious artifact of the measurement process. In Einstein’s system bodies move through inertial space and also move through each body’s own personal gravitational space. The meaning of the Equivalence Principle cannot be addressed in this system because it is used as a metaphysical constant within the equations.

In pushing gravity theories, the force of gravity is produced by the absorption of tiny unidentified high speed particles that are assumed to exist uniformly distributed throughout all of space. For example, bodies are pushed against the surface of the earth because they absorb more of these particles coming down from space than coming up through the earth because the mass of the earth has absorbed some of the particles coming up from that direction. These theories have no explaination for the Equivalence Principle and generally ignore the concept altogether.

In empirical gravity theories, gravity is described totally in terms of its physical measurements and no metaphysical principles such as equivalence are offered to nullify the readings of measuring instruments. The apparent attraction of gravity is caused by the easily measured constant upward acceleration of the earth’s surface. Gravity is caused by the gradual and constant expansion of matter and time. According to these theories the Equivalence Principle has no meaning because it has no measurable characteristics. A falling body does not accelerate downward because no such motion can be measured. It remains motionless while the surface of the earth is measured to accelerate upward.

The gravity cannon experiment is very simple yet decisive, and could be performed very easily and inexpensively. All that would be required is an apparatus similar to that described here and a video camera to record and time the gravitational motion that occurs. Aside from the large cost of transporting it into Earth’s orbit aboard the space shuttle, the cost of the equipment itself would be minimal. Besides being able to differentiate between competing gravity theories this experiment would also provide a means to verify earthbound measurements of the gravitational constant. Also, it would provide the ultimate test of the Equivalence Principle.

The apparatus to be used in this experiment consists of a glass tube, two glass spheres, and a gold ball, which is somewhat smaller than the hole through the center of the tube. One glass sphere (A) has a hole through the middle, which is the same size as the outside diameter of the tube, so that it can slide up or down on the tube. The other glass sphere (B) has a hole the size of the tube that is only half way through it, and also a recess cut into its center so that the gold ball can rest at its center. The size of the glass spheres is such that each has the same mass.
In the pushing theories of gravity the assumption is made that multitudes of tiny momentum carrying particles impinge upon matter from all directions and impart a portion of their momentum to the bodies that they pass through. In these drawings a cross section of the experimental apparatus is shown with black lines at 5 degree intervals representing the paths of the particles. The dotted lines show the paths of the particles as they pass through the glass tube and the glass spheres and impart some of their momentum to them. The white arrows show the direction of force being applied to the gold ball when located at that particular position in the apparatus. To determine the direction and magnitude of the force exerted on the gold ball we merely measure the lengths of the dotted lines on each side of the gold ball. Force is exerted in the direction of the greatest number of dotted lines.
In Absolute Motion Theory, gravity is caused by the expansion of matter and time. In these drawings the glass tube and gold ball are shown at equal intervals in time as each expands gravitationally. As can easily be seen from this sequence of drawings the motion of the ball toward the center of the tube is apparent rather than real. It is only the extremities of the tube and ball that move while their centers of gravity, represented by the dotted lines, remain the same distance apart within absolute inertial space.

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