Physicists suggest possible existence of other kinds of dark matter

(Phys.org) —A team of Harvard University physicists has proposed the possible existence of a type of dark matter not described by current physics models. In their paper published in the journal Physical Review Letters, the team suggests it's possible that not all dark matter is cold and collision-less.

In the visible universe, galaxies form into a disk shape—the Milky Way is a good example. All of its members align roughly along a single plane, this due to the forces of gravity and spin. Objects form into masses which, over time, spread out into a disk shape. Dark matter, on the other hand, appears to hover around galaxies like a halo, at least according to current models. It's seen as dark, cold and with so little energy that dark matter particles rarely if ever run into one another. The researchers in this new study suggest there may be other types of matter, however, that behaves more like visible matter. And, because of that, they suggest it could bunch up due to dark-matter-type gravity and form disks as well. These disks, which they describe as dark matter component double-disk dark matter, could represent as much as 5 percent of all existing dark matter.

For dark matter to clump, it would need to have other properties similar to visible matter as well. For that reason, the researchers suggest it's possible that there exists dark atoms, dark photons, and likely some form of dark electromagnetic force as well.

Research on dark matter over the years has led to a model that describes dark matter as existing in a ball shape—galaxies sit in the middle of the ball, which would mean observers living in a galaxy would "see" it as existing everywhere around them. But it's possible that other types of shapes exist as well, the researchers suggest, because there are other types of matter in the visible universe. They note that baryonic matter (matter made of strongly acting fermions known as baryons) is believed to make up approximately 5 percent of all matter in the known universe. For that reason, they conclude that it would appear likely that similar differences in dark matter would occur as well, and perhaps in nearly equal proportions.

If true, it would mean there could be whole dark galaxies out there, undetectable, yet as real as those we can see with the naked eye. Much more research will have to be done in this area before adding such types of dark matter to models in general use, of course. Until then, it will remain an abstract theory.

Abstract
We point out that current constraints on dark matter imply only that the majority of dark matter is cold and collisionless. A subdominant fraction of dark matter could have much stronger interactions. In particular, it could interact in a manner that dissipates energy, thereby cooling into a rotationally supported disk, much as baryons do. We call this proposed new dark matter component double-disk dark matter (DDDM). We argue that DDDM could constitute a fraction of all matter roughly as large as the fraction in baryons, and that it could be detected through its gravitational effects on the motion of stars in galaxies, for example. Furthermore, if DDDM can annihilate to gamma rays, it would give rise to an indirect detection signal distributed across the sky that differs dramatically from that predicted for ordinary dark matter. DDDM and more general partially interacting dark matter scenarios provide a large unexplored space of testable new physics ideas.

3.8 /5 (26 votes)

I think a lot of the problem arises from sheer inertia built into the university system from the tenure system. The old guard is protective of its turf by its very nature and add tenure to academe and then political granting and funding of research dollars based on giving too much weight to the “Appeal-to-Authority Fallacy” and new ideas and new scientists don’t get the attention they deserve.

It is especially difficult if the good scientific work is being done on the side that has been politically “demonized” so that good scientists will dismiss the topic out of hand because scientist X has publicly denounced it as pseudoscience. Such was the case with Carl Sagan’s denunciation of the works of Immanuel Velekovski. . . Velekovski’s work became anathema in science, even though a scientist who had read a good portion of his pre-publication draft had found many of his facts and hypotheses compelling, because of Sagan’s very public criticism. . . yet Sagan later admitted he had NOT BOTHERED TO READ THE WORKS HE SO VEHEMETELY CRITICIZED! He stated that it was obvious they were wrong because they challenged the “known facts” that the Solar System was pretty much now as it always has been as has the Earth and there is no room for catastrophism. The scientist who HAD read Velekovski’s work felt compelled enough to write the forward to his first book “Worlds in Collision.” His name? Albert Einstein. Of course he didn’t publish his forward in the national scientific press.

It is quite interesting to note that Velikovski made specific predictions about conditions on Venus in 1950, a time when orthodox Astronomers and cosmologists like Carl Sagan were predicting Venus would be found to have a planet girdling ocean with a high carbon dioxide atmosphere with a surface temperature of only about 40° over that of the Earth’s own temperature, with an atmosphere much like Earth’s and that it would be possible for mankind to mount a manned expedition to Venus and colonize it. Venus was considered by some as a “second Earth” with a habitual temperate zone near the poles. Velikovski, on the other hand, basing his argument on Mythology which holds that Venus is a newly born planet that was once a comet born out of Jupiter, predicted that Venus would be an inhospitable oven of a planet still cooling from the heat of its creation and its atmosphere would be a reducing atmosphere of acids at nearly 90 atmospheres pressure composed of aldehydes and methane, at temperatures hot enough to melt tin and lead. No water would be found anywhere as the heat and pressure would preclude its formation. Guess who was proved right, the orthodox astronomers like Sagan or the “pseudoscientist” Velikovski when the Russian Venera project probes touched down on the Venusian surface and lasted only hours because of the 90 bar atmosphere at 860° F (hot enough to melt tin and lead), composed of acidic, reducing gasses including large percentages of methane and aldehydes and NO WATER)??? So, was Carl Sagan right to criticize and demonize and dismiss out of hand a work he did not even bother to read, thus creating a modern shibboleth that most scientist believe to this day: “Immanuel Velikovski is worthless tripe?”

We are seeing similar demonization in climatology today. Anyone who disagrees with the anthropogenic global warming crowd is labeled a “denier” and ostracized, defunded, and considered somehow “evil” and “sick.” They, too, are being labeled “pseudoscientists.” In case readers don’t recognize it, that’s another logical fallacy called argument ad hominem. In other words, don’t attack the case, attack the messenger.

P.S. no peer review has been able to refute Velikovski’s scholarship on comparative mythology. You may disagree on his conclusions, and I do on a lot, but his facts and research are impeccable.

Gather sufficient evidence and it will go bye-bye. And that’s the way it should be.

The evidence has been overwhelming for years. . . But the orthodox cosmologists and astronomers will strain at gnats and shove camels through eyes of needles to ignore that evidence. When the Electric Universe Cosmologists made 19 specific predictions about what would happen when the Deep Impact space probe struck comet Tempel 1, those paragons of science bent over backwards to ignore them. When every single one of the nineteen proved to be right on the money, they redoubled their efforts to ridicule them, despite their complete accuracy and vindication of events. One of those predictions was that the impact would reveal there would be no H₂O, let alone ice found on the "dirty snow ball" that the "accepted theory of comets" maintained they were composed of. The impact revealed ZERO water. . . Which astounded the orthodox astronomers and cosmologists because they were certain that comets were "dirty snow balls!" But, instead of saying "Congratulations, you were right!" To the Electric Universe Cosmologists who predicted this finding, they claimed to find water when they analyzed the dust and found a Hydroxyl molecule (OH), Hydrogen, and Oxygen among the ejecta and announced officially "Voila! We found Water! Or, at least chemicals, that in the right conditions can combine to make water. . ." Without saying that there was less than 0.01% of the amount required even IF they magically combined to make the water! The other 18, including the double bolt of lightning that blew out the on board electronics a split-second before the craft hit the comet, have gone unexplained in the standard, orthodox cosmology. . . and are being ignored, swept under the carpet. That is willful ignoring of the facts and evidence. . . and there is plenty of evidence of deliberate sabotage of the work of Electric Universe cosmologists, from deliberately canceling grants, deep-sixing papers, and the blackballing or refusal of tenure to educators who dare to research, publish or even discuss the concept. . . Despite the fact that a couple of Electric Universe cosmologist have won Nobel prizes.

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