What if Einstein was both right and wrong? What if Newton was both right and wrong? How would we know?
By this I mean Einstein views gravity as inertial motion between two moving frames of reference in a curved space time. He believed the total amount of energy in a given space will tell the space how to bend. Yet what if it’s the force of gravity telling space how to bend?
There is a huge difference between the force of gravity and the force of magnetism. Magnetism is several orders of magnitude stronger than gravity, this discrepancy has mystified science for generations, leading to ideas about extra dimensions even a multiverse where a single force is distributed until it is the weak field we experience. One obvious difference between gravity and magnetism is one appears to be a interaction with space, while the other an interaction in space.
However if gravity was causing the bending of space, then the energy would be effectively absorbed by space, leaving only a fraction of its original intensity to be felt by objects in a given reference frame.
If gravity was a force, and that force bend space, both the predictions of Einstein and the predictions of Milgrom’s laws would be valid amd provable. Objects would still follow world lines, we would still see gravitational lenses and waves, light would still bend around large masses.
At the same time the predictions of Milgrom’s laws would also be true in the same framework as it would be the curved spacetime that would provide the Shwarzchild radius for the force to transition as predicted.
For those who don’t know the details Milgrom’s laws are often referred to as MOND, or Modified Newtonian Dynamics. Under the hood he proposes a Shwarzchild radius which allows the force of gravity to transition from an inverse square of the distance between objects to simply the inverse of that distance. This makes the force of gravity weaker faster the further you go from the center of mass, this would have the effect of an apparent acceleration on bodies at greater distances. Rather than continuing to slow as we see the planets do, things would begin to speed up. Allowing for the edge stars in galaxies to move a specific velocities without the need for dark matter.
One reason this is compelling in my mind is the only other analogous force to gravity, magnetism, experiences exactly this kind of force transition between the near and far fields. In the near field the magnetic force is the inverse cube of the distance, in the far field it is the inverse square. This effect is know to be because the electric field falls of faster than the magnetic field.
If in the equations of gravitational force the bending of space acted as the near field and beyond where it is not strong enough to curve acted as the far field the net result would be exactly the same. Einstein would be right, Newton would be right. In essence we would be splitting the difference with a new description of gravity as both force, and effect.
I wonder what kinds of predictions could be made for a binary force of gravity, and if they would be testable?