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A pair of researchers from the University of Nevada, Reno, in an attempt to detect and better define dark matter, have pulled off a pretty amazing science experiment. The team used 16 years worth of GPS data to turn the whole planet into a massive detector that might detect clumps of dark matter that could extend beyond the solar system.
Dark matter makes up roughly 85% of all matter in the universe, which is a real bummer for us humans — as we simply have no idea what it is, what it looks like, nothing. Astrophysics has provided multiple evidence that it actually exists, but so far, it’s always been beyond our grasp. As generally tends to happen when faced with great unknowns, we do however have quite a lot of hypotheses pertaining to its nature.
"So, the two gathered data from the 32 satellites that make up the 31,000-mile-wide GPS constellation and ground-based GPS stations, retrieving figures recorded every 30 seconds for the last 16 years. Data was retrieved from sources around the world, and in particular from NASA’s Jet Propulsion Laboratory. They then used a model to sift through this data, looking for irregularities in atomic clock signals.
[...] Aaaaaaand they didn’t find anything. It’s a bit disappointing, sure, but it’s not really surprising given how elusive dark matter has proven itself to be up to now. It has to be said, however, that while the team didn’t find any definitive proof to support their theory, it could be that the effect is simply more subtle than anything we can pick up, or that the Earth crosses lumps of dark matter very rarely."
https://www.zmescience.com/science/earth-dark-matter-sensor-gps/
(Score: 2) by takyon on Sunday November 05 2017, @01:18AM (3 children)
Sounds like a false premise:
https://www.space.com/25359-dark-matter-milky-way-galaxy-fermi-discovery.html [space.com]
https://en.wikipedia.org/wiki/Dark_matter_halo [wikipedia.org]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by FatPhil on Sunday November 05 2017, @01:48AM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 5, Interesting) by Gaaark on Sunday November 05 2017, @02:44AM
Playing the linky game:
1. https://arxiv.org/abs/astro-ph/0601581 [arxiv.org]
"To make dark matter fit general relativity to the oberved galaxy rotations you have to assume that it stays spread out in a halo around the galaxy, and therefore does not have structure on small scales. Scarpa et al. looked at globular clusters which are small areas within the Milky Way, where the stars are arranged slightly more densely than in surrounding areas. They found that the globular clusters behaved like little galaxies: whenever their internal accelerations dropped below a critical acceleration, a0, their dynamics became non-Newtonian. Their crucial point was that you can't use dark matter to explain the anomalous dynamics of tiny globular clusters since to fit it to galaxies you've already specified it must spread out: you can't have it both ways." http://physicsfromtheedge.blogspot.ca/2013/04/data-points-way-globular-clusters.html [blogspot.ca]
2. https://arxiv.org/abs/astro-ph/0204521 [arxiv.org]
"Dark matter usually only needs to be added to the edges of galaxies since in their centres they behave normally. Sanders and McGaugh (2002) pointed out that the radius at which galaxies start to spin too fast for their own good, and to need dark matter, is not a set distance, but it always occurs where the rotational acceleration drops below 1.2*10^-10 m/s^2: a very low acceleration called 'a0': a regime not previous encountered by our experiments. This is difficult to explain by dark matter - you'd have to invent a kind of matter that suddenly appears when accelerations are below this value."
https://arxiv.org/abs/astro-ph/0601581 [arxiv.org]
"Since dark matter is needed only at the galactic edge, its supporters need to have some new physics that keeps it smooth and diffuse. Brilliantly poking a hole in that, Scarpa et al. (2006) looked at globular clusters which are small dense congregations of stars within the galaxy, a bit like clumps of mistletoe in an oak tree. They found that whenever the 'internal' acceleration of these clusters drops below 1.2*10^-10 m/s^2 (a0 again) they spin far too fast to be stable, just like the full-sized galaxies, but in these globular clusters this anomaly cannot be explained by dark matter, since to work for galaxies dark matter must be smooth on these smaller scales."
3. https://phys.org/news/2015-03-galaxy-clusters-collidedark-mystery.html [phys.org]
"Harvey et al. have looked at the light from familiar objects like galaxies as seen from behind galaxy clusters, and looked at the distortion in the images due to gravitational lensing. They know what a typical galaxy looks like: a disc, so if it looks like a U-bend instead when it's behind the galaxy cluster, then they can infer the bending of the light that must be occurring and assume this bending is due to dark (invisible) matter in the cluster. They looked at 72 galaxy cluster collisions, and have modeled the collisions using several kinds of dark matter, and have shown that the only kind of dark matter that fits the observations, is a kind that doesn't interact with itself. I'd like to point out here that this makes the dark matter hypothesis self-contradictory since the dark matter particles have to be given a lot of kinetic energy (momentum) so that inertial/centrifugal forces keep them spread out in their usual orbital halo, but if you now imagine that two clouds of dark matter hit each other there should be a 'push' as the particles collide. This study proves there isn't any such push, so the simplest solution is that there is no dark matter. "
--- Karl Popper made a statements that should by engraved above the entrance to every proud physics department:
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 2) by maxwell demon on Sunday November 05 2017, @07:19AM
Your spoiler apparently is made of dark matter.
The Tao of math: The numbers you can count are not the real numbers.