Slashdot Mirror
Mysterious X-ray Signal Hints At Dark Matter
Astronomers using the Chandra X-ray Observatory and the XMM-Newton have recorded an unusual emission of X-ray light from a remote cluster of galaxies which may turn out to be evidence of dark matter.
Astronomers think dark matter constitutes 85% of the matter in the Universe, but does not emit or absorb light like “normal” matter such as protons, neutrons and electrons that make up the familiar elements observed in planets, stars, and galaxies. Because of this, scientists must use indirect methods to search for clues about dark matter. he latest results from Chandra and XMM-Newton consist of an unidentified X-ray emission line, that is, a spike of intensity at a very specific wavelength of X-ray light. Astronomers detected this emission line in the Perseus galaxy cluster using both Chandra and XMM-Newton. They also found the line in a combined study of 73 other galaxy clusters with XMM-Newton. ... The authors suggest this emission line could be a signature from the decay of a "sterile neutrino." (Abstract.) Sterile neutrinos are a hypothetical type of neutrino that is predicted to interact with normal matter only via gravity. Some scientists have proposed that sterile neutrinos may at least partially explain dark matter.
Umm.. Can someone translate this into English?
Phlogiston, the luminiferous aether, the Rutherford atom, dark matter, dark energy, the Higgs field...
Maybe one day we'll explore the idea that the geometry of space-time isn't flat, and that most of our constants aren't.
Here, I broke it down for you.
Not without a bong.
Granted I know nothing about such matters, but I wondered why time couldn't be dark matter?
Be seeing you...
"When the Sun shines upon Earth, 2 – major Time points are created on opposite sides of Earth – known as Midday and Midnight. Where the 2 major Time forces join, synergy creates 2 new minor Time points we recognize as Sunup and Sundown. The 4-equidistant Time points can be considered as Time Square imprinted upon the circle of Earth. In a single rotation of the Earth sphere, each Time corner point rotates through the other 3-corner Time points, thus creating 16 corners, 96 hours and 4-simultaneous 24-hour Days within a single rotation of Earth – equated to a Higher Order of Life Time Cube."
I just realized this reference may be too old, and that made me sad.
Tried that. Still gibberish... Maybe I should try again...
Courtesy of Omicron Persei 8.
Prepare to die, human scum!
Not without a bong.
Tried that. Still gibberish... Maybe I should try again...
You also need a bag of Oreo flavored Doritos...
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
Lrrr here, that x-ray burst was just Ndnd blowing up another microwave oven with tin-foil.
If photons with a frequency in the visible spectrum don't react with "dark matter" than why would photons with a frequency in the xray spectrum?
Anyone who does not agree with the preceding statement is probably an educated stupid fool.
Hey look, it's $something_we_dont_understand, and ooh, I can claim it's evidence for $todays_fad!
Astrophysics is big, messy, complicated, and difficult to measure. We just can't send probes to other galaxies to see what's really going on. Most of the time these things have more mundane explanations. But, until we figure out why galactic rotation curves are wonky, everyone will claim everything is due to dark matter.
1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0.
Do you have a newsletter?
Why do these crackpot-darkmatter-theories-du-jour all smell like mysticism?
What is the best discussion of galactic rotation curves? Best for a layperson, I should say.
If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
Because you don't understand them, so you assume they must be hokum.
The Time-Life Building isn't in Time Square. It's on 6th Avenue.
Hey look, it's $something_we_dont_understand, and ooh, I can claim it's evidence for $todays_fad!
Astrophysics is big, messy, complicated, and difficult to measure. We just can't send probes to other galaxies to see what's really going on. Most of the time these things have more mundane explanations. But, until we figure out why galactic rotation curves are wonky, everyone will claim everything is due to dark matter.
Today's fad? Dark Matter as an idea has been around for many decades (in some form since the 30s). It's supported by a massive amount of observational evidence - its not just rotational curves of galaxies. Its lensing observations and cosmic microwave background observations and velocity dispersion measurements etc. If you are going to claim that scientists don't know what they are doing, at least take the time to read the wikipedia article on Dark Matter or something similar - it would give you some idea of all the evidence you are unaware of.
On top of that, many of these observations use completely independent areas of physics. For example, rotational curves of galaxies use Newtonian Mechanics, while lensing observations of clusters of galaxies use General Relativity. These are completely independent sets of physics, yet they predict consistent amounts of dark matter. So why would completely independent sets of physics all predict the same amount of dark matter from observations? Well, the most mundane answer is that dark matter is real.
Weed isn't going to get you that far out. Try some ketamine!
I dunno about Time Cube, but I feel like the Thyme Cube guy is on to something.
But, until we figure out why galactic rotation curves are wonky, everyone will claim everything is due to dark matter.
Well, rotation curves, gravitational lensing by galaxies, missing amounts of matter needed in the beginning universe to show us what we are seeing today, and about four other separate methods of observations that are all hinting at the same thing. Thing is that this isn't a fad, it's been one of many different theories put forth and tested since these observations started popping up in the early part of the 20th century. So far, everything theory that hasn't been "matter that doesn't interact with EM radiation" has failed while "dark matter" actually has successes such as the Bullet Cluster. Meanwhile, such explainations such as MOND, modified gravitational equations, have yet to come up with even a hypothetical example that matches what we see. It's not a fad at this point, just tested science. Difference is that you are just hearing about it. It is a developing theory, less than a hundred years old from the first observational evidence, but at this point, if what is causing all of these observations isn't "matter that doesn't interact with EM radiation", it's something that acts just like it and is much stranger.
Let's have some fun. Also remember that luminiferous aether was an idea that was around for a long time as well. Dark matter is a difficult-to-disprove fad, without any real competing ideas. That will not always be the case.
1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0.
Well yes but if I had typed all that in my original post it would not have been as pithy and interesting. I'm not just hearing about this, I've written many academic papers on it, and I have serious reservations about the idea. *sigh* back to work...
1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0.
It depends what kind of english?
Normal human with average IQ and understands that science is real?
Or
Extremist right wing moron speak?
Wikipedia is usually a good reference. These two articles talk about it. It's the oldest evidence for "dark matter". Either that or it's evidence that gravity doesn't behave entirely the way described by Einstein. The latter view has fallen out of favor due to the lack of good theories adopting that viewpoint. The former has fallen into favor due to the copious selection of theories containing a particle with little or no interactions (it's easy to do). Neither of these theory-spaces has been proven to be correct (yet).
1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0.
The AC is saying that we should pity the fools, those nutless neutrons.
But, until we figure out why galactic rotation curves are wonky, everyone will claim everything is due to dark matter.
Actually this is explained by most of the Global Warming models.
Gee, it would be a real shame to lose pithiness and interest by not oversimplifying something to the point of possibly being misleading...
Normal human with average IQ and understands that science is real?
Or
Extremist right wing moron speak?
I was hoping you could translate it into left wing moron speak, perhaps using a metaphor involving healing crystals and/or homeopathy. That'd be super, thanks. If that's too hard, perhaps just translate it into some sort of yoga-energy-manipulation example, or maybe use the interaction of wind turbines killing thousands of bats as an analogy to the sterile neutrons decaying.
Don't disappoint your bird dog. Go to the range.
I think of this like string theory. They've got an answer searching for a problem.
Dark matter is one of those as well. They've theorized dark matter and attributed each unexplained item in astrophysics to it but have no real evidence it exists. As the other reply said to you this is not any different than the luminiferous aether that preceded it. Dark mater may or may not exist, but it would be foolish to attribute that which we can't explain to something that we can't see or measure. All those attributes of dark matter could easily be explained by other possible items including cosmic strings, wormholes, etc.
Dark matter is currently in vogue, that doesn't mean it's reality. Much of the hype behind dark matter is that if it exists and there is enough of it then it would explain the big bang. This has created a desire among some in the scientific community to want it to be true because it presents a nice clean solution with a recyclable universe. My personal feeling on it is that we're missing something big, that something is the explanation for where all the anti-matter went and it might explain many of these other anomalies that some are attributing to dark matter. I'm probably wrong, but I'm willing to bet so are the dark matter proponents.
It's a flock of pigeons.
The Slashdot armchair physicist brigade is out in force I see...
They've got an answer searching for a problem.
Right or wrong, dark matter is a textbook case of the exact opposite, an answer posed in response to a very specific problem...
Dark matter is currently in vogue
As is bashing dark matter via internet comments.
This has created a desire among some in the scientific community to want it to be true because it presents a nice clean solution with a recyclable universe.
This is all science is, the collection of theories that give the cleanest solutions. If you want the truth behind reality, go to a philosophy department instead.
Dark matter is one of those as well. They've theorized dark matter and attributed each unexplained item in astrophysics to it but have no real evidence it exists.
No. You got it exactly backwards. It's entirely the opposite of string theory. String theory was born as a theoretical construct and they're trying to figure out how to make predictions with it so they can see if it matches the real world.
When it comes to dark matter, what they have is a ton of observations which does not match the predictions of our current theories. What they see is mass being affected by something we can't see. So they've given it a label until we figure out what it is: dark matter.
So, just to repeat, dark matter is just a label given to what we can see happening but which we cannot currently explain with our established theories (GR and Standard Model). Hence it absolutely is reality!
And no, having "enough" dark matter would not explain the big bang. However certain dark matter theory-candidates give predictions which can explain the matter distribution in the galaxy, which neatly solves another puzzle.
You can read up on some details here about the latter: http://www.illustris-project.org/about/#public
Really, the "4-simultaneous 24-hour Days" of Time Cube are just so many words to express the concept of dividing the world into four time zones. That's it. Now let's go play some GameCube.
Can you share your alternative theory/papers? i am sure people here would be interested.
Do you have a newsletter?
No, just a buddy with keys to the Colorado research division of ConGlomCo...
but I may have said too much...
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
And certainly not University of Drexel. https://phys.cst.temple.edu/directory/faculty/tao.html [temple.edu]
Basically the dark matter may be nothing more than another type of neutrino, and we finally found its calling card.
It took me 30 seconds searching to find a couple of dozen papers in this general field of research, by someone called "McElrath". I know that it may seem heretical to you near-7 digiters, but some people use their real names (or in my case, profession) here, and have done for approaching two decades now.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"