Posts about dark matter

Is Dark Matter an Illusion?

Open access letter asks – Is dark matter an illusion created by the gravitational polarization of the quantum vaccum? by Dragan Slavkov Hajdukovic, CERN

Assuming that a particle and its antiparticle have the gravitational charge of the opposite sign, the physical vacuum may be considered as a fluid of virtual gravitational dipoles. Following this hypothesis, we present the first indications that dark matter may not exist and that the phenomena for which it was invoked might be explained by the gravitational polarization of the quantum vacuum by the known baryonic matter.

Let us start with a major unresolved problem. The measured galaxy rotation curves remain roughly constant at large radii. Faster than expected orbits, require a larger central force, which, in the framework of our theory of gravity, cannot be explained by the existing baryonic matter. The analogous problem persists also at the scale of clusters of galaxies.

The favoured solution is to assume that our current theory of gravity is correct, but every galaxy resides in a halo of dark matter made of unknown non-baryonic particles (for a brief review on dark matter see for instance: Einasto, 2010). A full list of the proposed dark matter particles would be longer than this letter; let us mention only weekly interacting massive particles and axions. In spite of the significant efforts dark particles have never been detected…

The scientific inquiry process continues to be used to try and explain the evidence we gather. Unsettled areas of science show how difficult the discovery process is. Once we have settled on theories it is so easy to explain why basic truths of evolution, geology, chemistry… result in what the evidence shows. But getting to the scientific consensus is a challenging process.


Dark Matter Is an Illusion, New Antigravity Theory Says

Physicist David Evans called the new study a “very interesting theoretical exercise,” but he said he isn’t ready to abandon dark matter just yet. “The evidence for dark matter is now very compelling,” said Evans, of the University of Birmingham, who leads the U.K. team for the ALICE detector at CERN’s Large Hadron Collider.

For example, in 2006 astronomers unveiled a photo of two colliding galaxies known as the Bullet cluster that purportedly showed the separation of matter from dark matter. A similar effect was observed in the Pandora cluster earlier this summer, said Evans, who was not involved in the study.

Hajdukovic said he is currently expanding his theory to account for these observations. His preliminary calculations, he said, suggest that “what is observed in the Bullet cluster and more recently at the Pandora cluster may be understood in the framework of the gravitational polarization of the quantum vacuum.”

CERN physicist Michael Doser agreed that Hajdukovic’s ideas are “unorthodox” but did not immediately dismiss the new theory…
“In a few years,” Doser said, “we should definitely be in a position to confirm or refute [Hajdukovic’s] hypothesis.”

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More Dark Matter Experiment Results

A dark-matter experiment deep in the Soudan mine of Minnesota now has detected a seasonal signal variation similar to one an Italian experiment has been reporting for more than a decade.

The new seasonal variation, recorded by the Coherent Germanium Neutrino Technology (CoGeNT) experiment, is exactly what theoreticians had predicted if dark matter turned out to be what physicists call Weakly Interacting Massive Particles (WIMPs).

“We cannot call this a WIMP signal. It’s just what you might expect from it,” said Juan Collar, associate professor in physics at the University of Chicago. Collar and John Orrell of Pacific Northwest National Laboratory, who lead the CoGeNT collaboration, are submitting their results in two papers to Physical Review Letters.

WIMPS might have caused the signal variation, but it also might be a random fluctuation, a false reading sparked by the experimental apparatus itself or even some exotic new phenomenon in atomic physics, Collar said.

Dark matter accounts for nearly 90 percent of all matter in the universe, yet its identity remains one of the biggest mysteries of modern science. Although dark matter is invisible to telescopes, astronomers know it is there from the gravitational influence it exerts over galaxies.

Theorists had predicted that dark matter experiments would detect an annual modulation because of the relative motion of the Earth and sun with respect to the plane of the Milky Way galaxy.
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Looking for Signs of Dark Matter Over Antarctica

Dark Matter Proof Found Over Antarctica?

High-energy electrons captured over Antarctica could reveal the presence of a nearby but mysterious astrophysical object that’s bombarding Earth with cosmic rays, researchers say. Or the electrons may be the long-awaited physical evidence of elusive dark matter.

Either way, the unusual particles are exciting for astrophysicists, who say they could someday confirm or deny decades of unproven theories. “In the first case, we have now seen for the first time a nearby source of cosmic rays.

Cosmic rays are not beams per se but are any protons, electrons, and other subatomic particles that careen toward Earth from a variety of sources, including the supernova explosions that mark the deaths of stars.

Most of the cosmic electrons that reach Earth are low-energy, because the highest-energy ones fizzle the fastest and don’t last long enough to get here.

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