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Astronomers Make Important Dark Matter Discovery
saudadelinux writes "To quote a press release on NASA's site, astronomers using the Chandra X-ray Observatory have discovered 'how dark and normal matter have been forced apart in an extraordinarily energetic collision.' There will be a briefing at noon, August 21 ET, on this discovery, with streaming media provided by NASA, and some details of the research posted on Harvard's Chandra site just beforehand."
How about waiting for the 21st and THEN posting a story. There is literally nothing of substance yet. Oh wait, this is Slashdot. We'll just have it posted again in two days, then on the 21st, then on the 25th, etc.
If you shine a torch at some dark matter what does it become?
Isn't dark matter just all the none illuminated items in the universe?
Rocks and stones and humans and plants and animals and silicon and paper and all these things are what I would consider dark matter, I might be wrong but someone could add some illumination on the subject I would be most grateful.
liqbase
It says "noon"... maybe RTFS before trying for a first post?
Now dark and normal matter will be one big family again, obviously with court supervision.
As long as NASA doesn't try to measure DM in metric units, everything should go just fine.
"We are all geniuses when we dream"
- E.M. Cioran
August 21 Eastern Time? Wow, great.
This is news to announce there will be news at a later date.
the future will be here, any day now
A feeling of having made the same mistake before: Deja Foobar
Due to recent events at NASA, we'd appreciate everyone helping out by recording the stream of the event, and puttting it... well somewhere you can find it later.
Cool! Now I can get started on my warp engine!
Yours, Zephram Cochrane
Dark Reflection
So what's the matter, NASA?
Full Tilt
Will Hannibal Lector please stop eating the brains of astrophysicists.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
We like to refer to it as "matter of color."
GetOuttaMySpace - The Anti-Social Network
How about "Slashdot Announces NASA Announces Announcement of Dark Matter Discovery"?
Less is more.
And on monday August 21, 2006 at 12:00 PM CST WDAF Channel 4 Fox News in Kansas City will air an hour long program detailing the latest news, weather and sports for their local viewing area.
Details as yet are unclear as to the specific content.
Someone's giving us ADVANCE NOTICE on Slashdot and you're COMPLAINING?!?!?!
I can't count how many times I've read something on Slashdot about something cool that's already happened, just barely, and said "Once again, information I could have put to much better use YESTERDAY!!!
Zonk, pay no attention to the criticism; I for one WELCOME some in-advance info (might even vote for it for "overlord"...)
This space intentionally left (almost) blank.
It's never been about how many planets are enough, and it's not just about Pluto. It's about how you define a planet.
It's, in a nutshell, about science: attempting to actually classify and understand the universe. Just proclaiming "ok, I hereby do dub Pluto a planet" is ok for everyday life, but a bit too vague for science. It's like you can talk generically about "radiation" in casual conversation or in super-hero comics, but to a scientist that's uselessly vague. A scientist will be more interested in what _kind_ of radiation (i.e., the exact particle), at what energies, etc.
The same happens in astrophysics. You can't just say "ooh, that's a pretty star", because that doesn't give you much to work with. Is it a planet? An asteroid? A comet? A star? A nova? A white dwarf? What? There are very good reasons to split hairs there, because out of such splitting hairs comes the understanding of what they are and how they work.
E.g., from the splitting of hairs as to how we classify stars came such categories as "white dwarf." In turn, that let us wonder about how big a white dwarf can be, which gave us the Chandrasekhar limit. In turn that told us that when a star goes over (actually it later it turned out that when it's just right under) that limit, it goes *KABOOM* in a spectacular Type Ia supernova. Since it happens at the exact same point, it tells us that every Type Ia supernova is exactly the same as any other one. Which in turn lets us use them to measure distances and velocities in distant galaxies. And from those came a bunch of other astrophysics stuff.
_That_ is why for science it's important to worry about such distinction. Sure, you can get through your everyday life without ever worrying about the difference between Pluto and an asteroid, or between a Type Ia and a Type 1b supernova. But for scientists, it's an entirely different situation.
The informal proclaiming which is what also doesn't scale. When you deal with a whole universe worth of stuff, you have a continuum of things, ranging from individual nuclei all the way to the super-massive black holes in the centre of galaxies. And there are trillions of trillions of them. You can't just go proclaiming for each and every single one of them if it's a planet, an asteroid, or what. You need some rule you can apply there.
A polar bear is a cartesian bear after a coordinate transform.
1) Turn off lights ...
2) stub toe on matter I can not see
3) patent dark matter and the process by which to make it
4)
5) profit
I'm god, but it's a bit of a drag really...
They're referring to the Bullet Cluster. It's a merging system where a small cluster is passing through a large cluster leaving a shockwave that looks like a bullet's wake, hence the name.
Dark Matter is collionless, i.e. the DM from the smaller system hasn't been slowed down by the collion and just zooms through. The gas is slowed down. So, the DM and gas are no longer in the same place. We can see the gas in an X-ray telescope (Chandra) and detect the mass by the gravitational lensing effect on the background galaxies.
This is the first time that this has been shown, and it basically disproves the entire category of theories that DM is an illusional caused by us not understanding the action of gravity at long ranges (MOND).
Abstract from a conference talk about this. (PDF)
Slashdot - Mutual Assured Discussion
Isn't this what a light bulb absorbs till it's full, and then you must throw it away?
I am the unwilling control for my Origin.
It *is* possible that future advances in astrophysics and cosmology will nullify the dark matter argument. It's just as likely that there *is* some sort of mass carrying matter out that that we have yet to identify. Either way it just shows how much we have left to learn.
It's a "Dark Discovery". We cannot observe it directly, but only infer its existance based on its secondary media influence.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
I would assume this is the Bullet Cluster (1E 0657-56) combined X-ray and weak lensing results that Maxim reported at the Six Years of Science with Chandra Symposium last November. The interesting bit is that in this merging galaxy cluster the hot gas (~ 30%) has collided and been brought to a stop while the dark matter (~ 70%) haloes which are collisionless have passed through each other and are offset from the gas. By plotting the weak lensing image (which shows the total mass) over the X-ray image (which shows the baryons/gas) you can therefore see the existance of dark matter, since the mass is in a totally different place from the gas you can see in the X-ray. This isn't a fundamentally new result but it is a very nice visual demonstration of the existance of dark matter. Rotation curves of galaxies and the temperatures of galaxy clusters had proved it already but with this you don't need to do any maths you can just see it. Page 25 of this 6.5 MB pdf is the one you want for the image.
Why? Thanks for asking! I'll tell you.
/. readership nonetheless mods the few informative posts up high enough that I can see them and therefore actually learn something interesting.
Because, no matter how many people post pronouncements definitively proclaiming that they, as expert perl programmers or css jockeys or what-have-you, know *quite certainly* that the term "dark matter" is just meaningless mumbo-jumbo, demonstating their amazing mental superiority over the cretinous astrophysics community and its running-dog lackeys in the Mainstream Science Media, the emergent wisdom of the oft-maligned
So thanks to drxray, and thanks to riptalon, and thanks to the readers who modded them up into my view.
This atrangely resambles those cosole pre-release press conferences where nothing new of the product is said at all. Hype machine at work for a science briefing, what's next?
16,777,216 comments ought to be enough for any forum!
Is this an advertisement for Galactus pulling a tablecloth out from under dark matter dinnerwear on "The Universe Has Talent?"
This sig seemed like a good idea at the time....
Although the press release says nothing, I would assume that there is some good evidence pointing to the detection of dark matter.
In the August 2006 Discover magazine, there was an interesting piece about Mordehai Milgrom, a physicist who does not accept the dark matter theory. Basically, he has been able to retrofit Newton's equations to allow them to predict on the galactic scale (one of the reasons for the belief in dark matter). Being only an amateur physicist, I can't tell which method is the simpler, the one that only changes the equations, but (almost) no one buys, or the one that postulates the existence of matter that absorbs all electromagnetic energy. I can't wait to hear what this press release tells us.
Actual NASA Photograph of their Dark Matter discovery can be found Here
Kent Simon Multitheft Auto