Do We Know What Causes Gravity?
Gravity may be caused by quantum information.
We’re often told that general relativity makes astonishingly accurate predictions, and that it’s passed every experimental test in the past 100 years. That’s only part of the truth. In simple systems general relativity works well. In complicated systems, like galaxies or the universe as a whole, its performance is abysmal.
Galaxies have more gravitational lensing and rotate faster than we expected. These findings, and a slew of related phenomena, show that in complicated systems gravity is stronger than what general relativity predicts. The source of this gravity is often attributed to dark matter, even though dark matter has not been directly detected in spite hundreds of millions of dollars in research funding.

Another problem with general relativity is that the universe appears to be expanding at an increasing rate, when general relativity predicts that gravity should slow the expansion of space. This accelerating expansion has been attributed to dark energy, which is like dark matter in that it has never been directly detected.
It’s possible that both the dark matter phenomena and the expansion of the universe can be explained by a better theory of gravity. I proposed a theory to do just that, the entropy scale factor. My theory was recently published in Physics Essays, and a version is available on my website.
The crux of my theory is that gravity may not depend on mass, like in Newtonian gravity, or energy and momentum, as in general relativity, but on entropy. Entropy is a measure of the hidden information in a system. A theory of gravity that depends on information could work better than general relativity for galaxies because galaxies contain both information about their constituent stars and information about how these stars relate to one another. This “extra” information about how the stars relate to one another would make the gravity of galaxies stronger in my theory, while not changing the predictions for individual stars that have already been verified by tests of general relativity.
The amount of entropy (and information) in the universe is always increasing. The scale of space is always increasing. Rapid periods of expansion have already been linked to rapid increases in the universe’s entropy due to particle creation and the growth of black holes. My theory adds to this by providing a mechanism for this expansion, and by linking it to other phenomena, like those attributed to dark matter.
Many studies will be needed to tell if the entropy scale factor is correct. Given the stagnation of research into dark matter and dark energy it may be time to look into this new theory.