The data is still open to some interpretation, and it's also only in the theoretical stage, but it appears that scientists have determined the probable mass of a single particle of dark matter.
I'm not certain I understand all the scientific jargon, but it SEEMS that someone got the idea of not just looking for dark matter, but also dark antimatter. And basically, these scientists have detected the dark matter based on the radiation that is produced by the annihilation of dark matter and dark antimatter.
If this is even halfway accurate, it's a really exciting development. And according to the calculations, one can find a few dozen dark matter particles in every cubic centimeter of space, right here on Earth! (Of course, it remains to be seen whether they can actually DETECT them...)
Apparently, one of the most unexpected parts of this is that the dark matter particle is so "light," and so far almost all scientists (especially the ones using the particle accelerators) have been looking for much more massive particles, and so the light ones probably slipped by undetected.
So, will it now be renamed to light matter? B)
Posted by Ritten (Member # 417) on :
Dark light matter. Black light matter. Out-of-sight light matter. Does it matter?
Posted by Balaam Xumucane (Member # 419) on :
dork matter.
Posted by Ritten (Member # 417) on :
Ouch....
Posted by MinutiaeMan (Member # 444) on :
Ritten, are you writing for a Dr. Seuss book now? Posted by Jason Abbadon (Member # 882) on :
quote:Originally posted by Balaam Xumucane: dork matter.
Proof of that can be seen each week on Kevin Sorbo's Andromeda. Posted by Ritten (Member # 417) on :
Yes but the title escapes me.....
Posted by Guardian 2000 (Member # 743) on :
Call me crazy, but given that we haven't yet determined just how much regular matter there is even in our own neighborhood -- new moons and asteroids being found all the time in this system, brown dwarf stars thought to exist all over the place (perhaps even closer than Alpha Centauri, according to some), planets everywhere, larger-than-thought concentrations of intergalactic gas and dust, the recent discovery of a ring of material extending north and south of the galaxy due to the Milky Way "eating" one of the Magellanic Clouds, and so on and so forth -- this whole concept of exotic dark matter is just really bothersome to me.
I get especially pissed off when they realize they've missed normal matter like brown dwarf stars or dead white dwarf stars that might exist all throughout the galaxy, and then hype that as "normal" or "baryonic" dark matter, and imply that it serves as proof of the more exotic stuff.
No, guys, that's just shit that you missed.
Posted by Ritten (Member # 417) on :
Gee, 2k, you can be such a downer man....
Posted by MinutiaeMan (Member # 444) on :
quote:given that we haven't yet determined just how much regular matter there is even in our own neighborhood
Compared to the mass of stars, finding ANY planets or asteroids is insignificant comparatively. In these locales, Jupiter is not even 0.1% of the mass of Sol itself!
A single galaxy has hundreds of millions -- or even billions -- of stars in it. Compared to that, who the hell cares if they miss a couple dozen or hundreds of stars? A single galactic cluster has several dozen galaxies in it, ranging in size from the dwarves that have only a few dozen thousand stars in them, to the truly massive ones that have billions.
Face it -- on the scale of the universe, individual stars are totally and completely insignificant. Take a look at this enlightening Map of the Universe within 14 billion light-years and try zooming in to see how close you need to get before you can see anything recognizable.
The simple fact is, that scientists can fairly accurately measure mass without needing to find every single star ahead of time. They can observe how other bodies are pulled by yet-unseen objects. They can measure the apparent brightness of Cepheid variables, which have a very specific and well-known period-to-luminosity relationship, letting astronomers determine pretty accurate distances to other galaxies. They can measure the Doppler shifts of emission lines from distant galaxies to actually determine their rotational speeds, and therefore also their collective mass.
If you know anything about astronomy in the large-scale universe at all, G2K, you'd know that it's impossible to explain the rotation of spiral galaxies like the Milky Way without dark matter. Without dark matter, a spiral galaxy could not maintain its uniform shape over time, because the stars would all have differing orbital velocities -- and stars orbiting further out from the galactic core would orbit at a much slower speed. (This is exactly why Mercury whips around the sun in less than two months, while it takes Pluto 250+ years to make a single orbit -- the same effect should be seen in the Milky Way, which would rip the spirals apart within a few million years.) For a spiral galaxy to maintain its shape, all of the stars in its spiral arms must have about the same orbital velocity. And that requires the presence of a large, previously-undetected mass that is concentrated around the edge (and beyond the edge) of the visible galaxy to affect the velocities of all those stars.
If you want more, I'd recommend looking at an astronomy textbook. I took an astronomy class last spring at the University of Delaware (taught by a professor who participated in the 2MASS survey, one of the most famous and productive civilian astronomy projects in the past decade). The textbook came with the CD for all of its material in it -- I'd be happy to send you a copy of the HTML file for the chapter on dark matter. Maybe after reading that, you can know what you're talking about.
Dark matter is not just some bizarre theory made up for the amusement of astronomers, so they can giggle at everyone who tries to report on their studies. It's a bizarre theory that tries to explain bizarre happenings in the universe. (I'd be willing to bet that a lot of scientists considered Einstein's theories as very bizarre before THEY were proven...)
Oh, and that "ring" of matter you alluded to was actually the Sagittarius Dwarf Galaxy, not one of the Magellanic Clouds... Posted by Ritten (Member # 417) on :
Tell me there is no God, who else can make a galaxy jump through a hoop???
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