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Dwarf Galaxies Dim Hopes of Dark Matter
An anonymous reader writes Once again, a shadow of a signal that scientists hoped would amplify into conclusive evidence of dark matter has instead flatlined, repeating a maddening refrain in the search for the invisible, omnipresent particles. The Fermi Large Area Telescope (LAT) failed to detect the glow of gamma rays emitted by annihilating dark matter in miniature "dwarf" galaxies that orbit the Milky Way, scientists reported Friday at a meeting in Nagoya, Japan. The hint of such a glow showed up in a Fermi analysis last year, but the statistical bump disappeared as more data accumulated. "We were obviously somewhat disappointed not to see a signal," said Matthew Wood, a postdoctoral researcher at Stanford University who was centrally involved the Fermi-LAT collaboration's new analysis, in an email.
or can know....or something like that.
Dark Matter is the Aether of the 21st century. Eventually we'll stop wasting money on finding it.
I'm an American. I love this country and the freedoms that we used to have.
i think at some point some scientists somewhere will work out that the statistical evidence is growing to show, more and more, that dark matter *doesn't* exist...
WTF
I love it when science can't explain something yet, it means we have so much more to learn.
The Dark Matter is still there, as something (we don't know what). This doesn't "dim" the existence of DM as an effect* at all. What this does is (again) dim some faint hopes it might be WIMPS. It doesn't constrain other models / theories at all.
* : even if the DM is MOND, or some other gravity correction, it might not be matter, but the effect would still exist.
If you want to be technical about it, you are creating an excluded middle.
Thinking that the current search for dark matter is wasted effort hardly makes you anti science. It just means you don't like a particular line of research. I happen to be very pro physics research but very anti spending on ever larger accelerators. While they do get results we haven't been getting very much in spinoff from them for a very long time.
Dark Matter and Dark Energy are not terms that should conjure up weirdness in your mind. Not at this point, anyway.
Neither concept has a shred of evidence behind it indicating that anything exotic is going on. If you really want a good handle on the terms, just think of them as "We hope some sources of energy and matter we can't detect are out there because otherwise, the math behind our hypotheses doesn't work."
It's a limitation of trying to figure out what's going on incredible distances -- and times -- from us with a combination of barely functional tools, our (decent, I'm guessing) grasp of science, and the participant's intuitions.
I've fallen off your lawn, and I can't get up.
There is no dark matter... it's a glitch in the machine.
That's not a bad thing; a glitch can be exploited.
It is very easy to imagine models for Dark Matter where the DM cannot annihilate with itself. In such cases there are only two ways to detect it: create it in high energy collisions such as those at the LHC or detect it bouncing off an atomic nucleus in extremely sensitive experiments placed deep underground to shield them from cosmic rays. The fact that there is no evidence of annihilating Dark Matter does not "dim hopes of Dark Matter" it just dims hopes of one particular class of model of Dark Matter.
If the LHC sees nothing in the next few years though it does tell us something: Dark Matter is unlikely to be a a massive particle which interacts with matter via the weak force. At LHC energies we can pretty-much exclude the mass range consistent with thermal production in the Big Bang for this class of particle. There are ways around this e.g. exotic production mechanisms or multiple types of particle contributing to Dark Matter but the simplest models for weak particles will be gone and axions might start to look even more attractive as an explanation.
It doesn't matter what you call it ... declining or dilution ... the end result is fewer women in CS career fields than men. The effect is less a less robust CS field and the resulting negatives that come along with a technology field operating with blinders.
They're creating a decently highly resolution map of dark matter around many galaxies. They can map it via its gravitational lensing. It distorts space and it is quite visible in that sense. They've already found dwarf galaxy sized clusters of this "unseen" mass. If it was any form of normal matter, we'd be able to detect it, as it would interact with light and block and or emit light in some way, but we do not see that, all we see is space warping from mass.
So yes, there is A LOT of evidence of Dark Matter.
Can't be brown dwarfs, thank's to micro lensing constraints. Can't be supernova, as it was present before the microwave background. It could be smaller compact stuff - see this for the current allowed holes in the condensed matter mass spectrum, and this for some ideas and references for an alternative DM theory involving condensed matter.
Why are scientists obsessed with finding the most exotic explanation of Dark Matter without first exhausting the more prosaic explanations? It is Occam's Razor upside down. I think that the reason is there there is a Nobel Prize and fame if Dark Matter turns out to be a particle, but there is no glory if it turns out to be something more ordinary such as neutral hydrogen, dust, etc. Even a modification of Newtonian laws at a distance to explain Dark Matter is not exotic enough.....so we have to endure Crackpot Cosmology Theory (CCT) of the week from here to eternity...
Even if it was "brown dwarfs", if there was 8x more brown dwarfs than matter that we can see, all of those brown dwarfs would just turn into stars in the first place. Matter that we see naturally coalesces over time, so it seems quite ludicrous to assume that the "hidden mass" is somehow normal matter that does not coalesces. It's still a good enough hypothetical that should be ran through the math grinder just to be sure as we're already grasping at straws, but I don't know how it passes the sniff test for people regurgitating this disproven idea.
I guess what I'm getting it at, is why do people think that it's normal matter that does not act like normal matter? That makes absolutely no sense. But like I said, was still worth running through the math grinder, just to be sure, as it's still plausible.
Don't know much about physics, but Newton's laws of motion were good and still work on a small scale for most practical purposes. Then we had the theories of general and special relativity, which work on larger scales and describe spacetime. Further we have quantum field theory, which describes interactions at an extremely small scale and apparently has yet to be unified with the G/S theories of relativity. The lack of unification leads me to believe that we're either too stupid to discover the missing link or that one or both theories are inaccurate. Now that our observable universe is pretty damn huge, a larger sample size to test our various theories against, it doesn't surprise me that things don't add up. There could be dark matter/energy, other dimensions/universes bumping into ours, a godlike noncorporeal alien race using quantum teleportation as its neural network and galaxies as its body, etc., but if I had to put good money on it I'd venture that our theories are wrong. Until current "working" theories can at least be unified, I'd hold off proposing things like the majority of all matter/energy in the universe not being directly observable. Errors on a small scale are negligible, but when applied at the insane scale of the universe they can't be ignored. Even if dark matter/energy do exist, our theories are probably still wrong.
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I don't know... I kind of like the fact that the universe is still such a mystery to us. With the large hadron collider there was almost a sense of let down that nothing exotic or unexpected appeared. That everything went according to our models.
Of course it flat-lined, they were using the Fermi Large Area Telescope (FLAT)!
Special relativity may not work well with black holes or quantum level stuff, but it seems to predict everything we can measure at the atom level or higher, perfectly. If special relativity is as wrong with something like handling whatever Dark Matter is trying to fix, then special relativity should be nearly useless as a tool for anything. Yet we use special relativity for every day items such as computers, cell phones, and GPS. Well, I may be mixing up "special relativity" and "relativity". I am a bit laymen.
As early as the 1670s, Newton used the idea of aether to help match observations to strict mechanical rules of his physics.
"The motion of light was a long standing investigation in physics for hundreds of years before the 20th century."
Ether theorists: Newton, Robert Boyle, Christiaan Huygens, Faraday, Lorentz, James Clerk Maxwell, Poincare...
It is noteworthy that, despite it being impossible to prove a negative, the ether has supposedly been disproven. So why does Wikipedia add a question mark to that section's title?
My own theory of the ether, gravity and QM.
I come here for the love
There is as much evidence of dark matter as there is of climate change. Quite a lot. Just because you are ignorant of that evidence does not make such evidence disappear.
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
With topics like global warming, Scientist can do no wrong. When it comes to cosmology, every dipshit thinks they have the answer in 5 seconds flat.
You are wrong. If your weren't such a dipshit you would have bothered to read up on the data a little bit, and then you would know you where wrong before opening that mouth of yours.
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
African-American matter is the correct term.
No, there's evidence of gravitational lensing. We still don't know much about gravity. We do know it can potentially be created with just energy and not mass though. So it's still likely that dark matter doesn't exist.
"Little People" Galaxies
That sounds like it'd be Fisher-Price's attempt to cash in on the popularity of LEGO film-to-game adaptations and The LEGO Movie.
It really boggles my mind that the guys studying this stuff haven't come to the conclusion that the matter "missing from universe" that they are trying to associate with Dark Matter is more than likely brown dwarfs or dense material with just can't detect yet from super nova explosions. WTF IS WRONG WITH YOU PEOPLE!
Yeah. All those smarty-pants scientists completely missed this.
Or it could be that brown-dwarf dark matter is inconsistent with what we know about primordial nucleosynthesis, plus it was searched for by gravitational microlensing experiments, and wasn't found.
There is no doubt that there is a dark matter "effect", it is just that we don't really know we will every find a particle that is "Dark Matter". I kind of dislike the name for that reason, maybe scientist are affected by this but your common layman seem to think one day we will have bottles full of "Dark Matter" we can use in some future technology. We simply know very little about what is causing the dark matter effect and we have much more knowledge about what it isn't than what is might be. The key is to keep an open mind about what we might be looking for.
If you look for the golfball particles, perhaps you can find the Dorf galaxies?
Tracy Johnson
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BT
There is plenty of evidence that the horizon exists also. I can see it and measure how far away it is. But for some strange reason, no matter how fast you travel, you can never reach it.
-- ssoorrrryy,, dduupplleexx sswwiittcchh oonn.. -Quote found on actual fortune cookie.
How would you tell the difference between energy that stays more or less in one place and matter? And what's with this indetectable energy? The idea of matter that doesn't interact electromagnetically seems very plausible compared to what you suggested.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
Energy doesn't stay in place, it moves from high to low. We'd quickly detect if it was a form of energy, unless it was a new exotic form of energy, which it could be, but much much less likely than it being an exotic form of matter.