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Dark Matter Filament Finally Found
An anonymous reader writes "Everyone is talking about the recent Higgs boson announcement by the scientists at CERN, but another significant scientific discovery was revealed this week as well. In a study published online in the journal Nature on Wednesday, scientists show that they have successfully found the first dark matter filament."
http://www.space.com/16412-dark-matter-filament-galaxy-clusters.html
First of all, don't go to "page 2" and I use that term loosely. Secondly, it doesn't mention a single scientific detail about how they determined that the light was being bent around a filament-shaped object compared to the starts behind it actually being in the location the light suggests. It merely states "They used a model to subtract out the masses of the galaxy clusters and then fit the remaining mass with a model of what a filament might look like. They found that a filament must be present." So in other words, they didn't find anything other than a mathematical equation suggesting dark matter exists. Congratuations are in order indeed.
Aha, someone posted a hair bit of time ahead of me a much better article so let me ammend that with the short version:
There are 2 galaxies kinda far apart but they're really overlapped from Earth's point of view. Like one is almost entirely behind the other. So the back galaxy's light passes along where the filament would be estimated to be between the galaxies. So the light travels through the dark matter's gravitational field for a really long time, running practically parallel to the filament. Even after that much light gravity tugging, it's barely perceptable by our current telescopes. So someone had some pics of this set of galaxies from 2001 but never did anything with them because they didn't realize the opportunity. This new team noticed it, compared it to background light to detect additional possible lensing, and discovered unmistakeable slight lensing. So something is obviously there and it has to be a particular shape, density, and reflect no light.
Well, except that if 80% of the mass in our galaxy was simply non-luminous, we'd still see the "haze" from it, just as we can see evidence of the existing hydrogen haze by it's characteristic absorbtion spectra, especially when starlight passes through nebula where the diffuse matter density is extremely high. Perhaps the vast majority simply formed gas giants and the like that were two small to "ignite", recent evidence does suggest wandering planets may be far more common than star-bound ones, but to get the 5:1 ratio still we'd be talking about 5000 Jupiters for every sun, and the sun is actually pretty tiny as stars go - with that many dark planets whizzing around it seems likely we'd see some evidence of them, likely of the frequent "Gas giant zooms through solar system, multiple planetary orbits disrupted, news at 11" sort. If the planets were smaller the "invasions" would be even more frequent, and if they were much larger (we're not sure of the exact limit) they'd spontaneously ignite
Then again - if using general relativity rather than Newtonian gravity actually does explain the odd rotational characteristics of our galaxy without reliance on massive amounts of additional matter then you may be right. There's still things like the Bullet Cluster that show evidence of something very weird going on though - the gravitational lensing seems to have become partially disconnected from the visible matter - if "dark matter" was simply non-luminous you would expect it to still have distribution and gravitational-collision properties similar to the glowing stuff, which is not the case there. Whatever is causing the lensing is behaving in a manner fundamentally different than the matter we can see, in fact it appears to be largely unaffected by the collision at all, which would seem to at odds with many "simple" dark matter theories as well (i.e. it's like normal matter, except light passes right through it).
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Un-doing 7 well-deserved mod points to post this, so pay attention. Higgs was not a given. A particle in the same range without the ability to generate the Higgs field was also a possibility. The team explicitly stated that further confirmation is needed before they can say they found Higgs, or a Higgs-sized particle that does not do the things Higgs Boson is supposed to do.
It is still up in the air as to whether we have a Higgs Boson, or a Higgs-less theory of mass. Obviously everyone is leaning towards Higgs because it matches predictions. But what if it is Higgs sized without having the correct properties? Then you're wrong, and also an idiot for assuming it is a given.
If we indeed found it, then you're a lucky guess at best.
I agree this is more important, but only because we have been zeroing in on a Higgs-sized particle for quite some time. Dark matter has been purely theoretical until now (and still this is only the first sighting, subject to review and revision as with all experimental results). More important because it's newer.
In truth, we won't know for a hundred years which is more important. If dark matter has been theorized since 1930's and we just confirmed it, it is no more important than such ideas as gravitational lensing which have been around for decades before being confirmed. We have known it for a long time, in other words. To me, more important would be strong evidence that a 90 year old hypothesis was completely incorrect and in need of revision.
Neither one of these, to me, beats a fat man finally seeing his toes after 30 years. He had a feeling they were there, and had been told as much, but to finally see them is a whole different ball game.