Professor Erik Verlinde, a theoretical physicist at the University of Amsterdam in the Netherlands, shocked the physics world last month. His emergent gravity theory introduced in 2010, received a major boost. A group of astrophysicists from the Netherlands, Germany, United Kingdom and Australia put to the test Verlinde’s theory by observing and analyzing over 33,000 galaxies.
After exhaustive observations the scientists concluded that Verlinde’s theory and Einstein’s gravitational theory explain equally well the bending of light due to the gravity of close objects. Verlinde added that this discovery clearly shows that dark matter does not exist.
The scientific community is comfortable with the laws of gravity formulated three hundred years ago by Isaac Newton—along with the relativity theory it amply explains gravity throughout the universe. These two theories offer the best explanation for the behavior of the universe, but we know that the outer regions of galaxies, like our Milky Way, rotate much faster around the center of their galaxies than can be explained by these theories. The amount of ordinary matter surrounding these celestial objects at the outer regions of galaxies is too small to account for the gravitational force needed to produce the high rotation spins. Something else must be responsible for the amount of gravitational force needed to produce this effect, so physicists proposed the existence of dark matter and dark energy, which is responsible for the accelerated expansion of the universe. Dark matter, according to these theories must comprise more than 80 percent of all matter in the universe. For many years dark matter has dominated scientific thought, but scientists have not been able to observe not even a single dark matter particle.
In the new paper published last month on the ArXiv preprint server at the Cornell University Library, Verlinde explained that there is no need to add the reclusive dark matter particles to explain gravitation, putting Einstein’s theory on the back burner. Instead he says that his theory accurately predicts the velocities of the star rotation outside and inside their galaxies, including our Milky Way. He proposed that the excess gravity in galaxies is the consequence of emergent gravity.
"We have evidence that this new view of gravity actually agrees with the observations," says Verlinde. "At large scales, it seems, gravity just doesn't behave the way Einstein's theory predicts."
The emergent gravity theory proposes that gravity is not a fundamental force, like electromagnetic or nuclear forces, but rather is the manifestation of the entropy of the universe (it “emerges” from or is the result of entropy), which always increases according to the second law of thermodynamics. This causes the universe objects to distribute in a way to maximize entropy. The effect of this distribution produces a “entropic force” that acts similar to gravity, and from this principle one can derive Einstein’s equations of general relativity, as Verlinde proved.
The emergent gravity theory provides a way to reconcile the contradictions between gravity on large systems and quantum mechanics at the atomic levels, but it is not a totally proven theory. Most physicists don’t believe it is a solid theory, but the idea is worth exploring. This latest publication adds a new interest because gravitational theory doesn’t combine well with quantum mechanics, so a new paradigm is needed. Both theories, the crown jewels of 20th century science, cannot be true at the same time. "Many theoretical physicists like me are working on a revision of the theory, and some major advancements have been made,” says Verlinde. “We might be standing on the brink of a new scientific revolution that will radically change our views on the very nature of space, time and gravity.”