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dark matter mapped
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It is the invisible material that makes up most of the cosmos. Now, scientists have created the first image of dark matter By Steve Connor, Science Editor Published: 08 January 2007 One of the greatest mysteries of the universe is about to be unravelled with the first detailed, three-dimensional map of dark matter - the invisible material that makes up most of the cosmos. Astronomers announced yesterday that they have achieved the apparently impossible task of creating a picture of something that has defied every attempt to detect it since its existence was first postulated in 1933. Scientists have known for many years that there is more to the universe than can be seen or detected through their telescopes but it is only now that they have been able to capture the first significant 3D-image of this otherwise invisible material. Unlike the ordinary matter of the planets, stars and galaxies, which can be seen through telescopes or detected by scientific instruments, nobody has seen dark matter or knows what it is made of, though calculations suggest that it is at least six times bigger than the rest of the visible universe combined. A team of 70 astronomers from Europe, America and Japan used the Hubble space telescope to build up a picture of dark matter in a vast region of space where some of the galaxies date back to half the age of the universe - nearly 7 billion years. They used a phenomenon known as gravitational lensing, first predicted by Albert Einstein, to investigate an area of the sky nine times the size of a full moon. Gravitational lensing occurs when light from distant galaxies is bent by the gravitational influence of any matter that it passes on its journey through space. The scientists were able to exploit the technique by collecting the distorted light from half a million faraway galaxies to reconstruct some of the missing mass of the universe which is otherwise invisible to conventional telescopes. "We have, for the first time, mapped the large-scale distribution of dark matter in the universe," said Richard Massey of the California Institute of Technology in Pasadena, one of the lead scientists in the team. "Dark matter is a mysterious and invisible form of matter, about which we know very little, yet it dominates the mass of the universe." One of the most important discoveries to emerge from the study is that dark matter appears to form an invisible scaffold or skeleton around which the visible universe has formed. Although cosmologists have theorised that this would be the case, the findings are dramatic proof that their calculations are correct and that, without dark matter, the known universe that we can see would not be able to exist. "A filamentary web of dark matter is threaded through the entire universe, and acts as scaffolding within which the ordinary matter - including stars, galaxies and planets - can later be built," Dr Massey said. "The most surprising aspect of our map is how unsurprising it is. Overall, we seem to understand really well what happens during the formation of structure and the evolution of the universe," he said. The three-dimensional map of dark matter was built up by taking slices through different regions of space much like a medical CT scanner build a 3-D image of the body by taking different X-ray "slices" in two dimensions. Data from the Hubble telescope was supplemented by measurements from telescopes on the ground, such as the Very Large Telescope of the European Southern Observatory in Chile and the Japanese Subaru telescope in Hawaii. Details of the dark matter map were released yesterday at the annual meeting of the American Astronomical Society in Seattle and published online by the journal Nature. The map stretches half way back to the beginning of the universe and shows that dark matter has formed into "clumps" as it collapsed under gravity. Other matter then grouped around these clumps to form the visible stars, galaxies and planets. "The 3-D information is vital to studying the evolution of the structures over cosmic time," said Jason Rhodes of the Jet Propulsion Laboratory in Pasadena. Astronomers have compared the task of detecting dark matter to the difficulty of photographing a city at night from the air when only street lights are visible. Scientists said the new images were equivalent to seeing a city, its suburbs and country roads in daylight for the first time. Major arteries and intersections become evident and a variety of neighbourhoods are revealed. "Now that we have begun to map out where dark matter is, the next challenge is to determine what it is, and specifically its relationship to normal matter," Dr Massey said. "We have answered the first question about where the dark matter it, but the ultimate goal will be to determine what it is." Various experiments on Earth are under way to try to find out what dark matter is made of. One theory is that it is composed of mysterious sub-atomic particles that are difficult to detect because they do not interact with ordinary matter and so cannot be picked up and identified by conventional scientific instruments. Comparing the maps of visible matter and dark matter have already pointed to anomalies that could prove critical to the understanding of what constitutes dark matter. |

im just really impressed that something only science fiction a couple of decades ago has been shown to most likely exist. respect to those people looking at the universe for something nobody can see
Great book that's easy to get into is Stephen Hawking's
"Universe Explained". And only has one equation.
Source:
http://news.independent.co.uk/world...icle2134891.ece
Thats sweet.
I don't buy it.
The whole "Dark Matter" thing.
I think that our current theories are unable to determine yet what actually happens out there in the void, and we keep building on TOP of old theories, instead of taking steps backwards to rectify errors. The reason we can't do this is most likely because our system of arithmetic itself may be the root of the problem, disallowing the cohesion of absolute information and theoretical inquery.
So yeah... we can't actually ascertain the weight of galaxies and solar systems, so we sloppily make up a variable, "dark matter", to encompass everything that we don't yet understand or doesn't fit correctly into our models.
I don't doubt that there are entire spectrums of vibrational waves as well as material objects that we can't even detect in *any* possible way yet. Overlapping universes, new types of states of matter beyond plasma, or maybe just errors in how mass actually functions in its non-dimensional reality.
Why is there even matter?
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| Originally posted by DJ Shibby I don't buy it. The whole "Dark Matter" thing. I think that our current theories are unable to determine yet what actually happens out there in the void, and we keep building on TOP of old theories, instead of taking steps backwards to rectify errors. The reason we can't do this is most likely because our system of arithmetic itself may be the root of the problem, disallowing the cohesion of absolute information and theoretical inquery. So yeah... we can't actually ascertain the weight of galaxies and solar systems, so we sloppily make up a variable, "dark matter", to encompass everything that we don't yet understand or doesn't fit correctly into our models. I don't doubt that there are entire spectrums of vibrational waves as well as material objects that we can't even detect in *any* possible way yet. Overlapping universes, new types of states of matter beyond plasma, or maybe just errors in how mass actually functions in its non-dimensional reality. |
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| Originally posted by DJ Shibby I don't buy it. The whole "Dark Matter" thing. I think that our current theories are unable to determine yet what actually happens out there in the void, and we keep building on TOP of old theories, instead of taking steps backwards to rectify errors. The reason we can't do this is most likely because our system of arithmetic itself may be the root of the problem, disallowing the cohesion of absolute information and theoretical inquery. So yeah... we can't actually ascertain the weight of galaxies and solar systems, so we sloppily make up a variable, "dark matter", to encompass everything that we don't yet understand or doesn't fit correctly into our models. I don't doubt that there are entire spectrums of vibrational waves as well as material objects that we can't even detect in *any* possible way yet. Overlapping universes, new types of states of matter beyond plasma, or maybe just errors in how mass actually functions in its non-dimensional reality. |
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| Originally posted by DJ Shibby I don't buy it. The whole "Dark Matter" thing. I think that our current theories are unable to determine yet what actually happens out there in the void, and we keep building on TOP of old theories, instead of taking steps backwards to rectify errors. The reason we can't do this is most likely because our system of arithmetic itself may be the root of the problem, disallowing the cohesion of absolute information and theoretical inquery. So yeah... we can't actually ascertain the weight of galaxies and solar systems, so we sloppily make up a variable, "dark matter", to encompass everything that we don't yet understand or doesn't fit correctly into our models. I don't doubt that there are entire spectrums of vibrational waves as well as material objects that we can't even detect in *any* possible way yet. Overlapping universes, new types of states of matter beyond plasma, or maybe just errors in how mass actually functions in its non-dimensional reality. |
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| Originally posted by pkcRAISTLIN you're gonna have to do better than that, if youre gonna fly in the face of popular expert opinion. |
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| Originally posted by DJ Shibby Hm... actually, I don't. I think I can have a different opinion than the general opinion if I please, whether you like it or not. And as your cute little oxymoron, where exactly do the popular experts get their qualifications? Oh... that's right, their models are mostly based on Einstein's model of relativity, in which he himself said that our theories are guesses that attempt poorly to mold to what is actual reality and not vice versa. You're gonna have to do better than that. peace |
We are one step closer!
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| Originally posted by pkcRAISTLIN what i meant was- these scientists are the ones that are looking for it (dark matter), theyre the ones crunching the numbers and evaluating the models. if youre going to disagree with them, then you should also be working through the same hypotheses, to show why theyre not accurate. basically im gonna accept their assessment at face value coz i certainly cant do the work myself. perhaps you can, and if so id love for you to explain it to me |
)
You know there's a scientist who wants to create a universe in a
lab? Supposedly it's 'safe'....
http://www.casavaria.com/sentido/sc...ew-universe.htm
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| Originally posted by DJ Shibby Hm... actually, I don't. where exactly do the popular experts get their qualifications? Oh... that's right, their models are mostly based on Einstein's model of relativity, in which he himself said that our theories are guesses that attempt poorly to mold to what is actual reality and not vice versa. |
The first post in this thread is fascinating. Dunno, how I missed that. One interesting article I did read was about the image of the Universe's first objects !! And here it is !
The right panel is an image from NASA's Spitzer Space Telescope of stars and galaxies in the Ursa Major constellation. This infrared image covers a region of space so large that light would take up to 100 million years to travel across it. The left panel is the same image after stars, galaxies and other sources were masked out. The remaining background light is from a period of time when the universe was less than one billion years old, and most likely originated from the universe's very first groups of objects � either huge stars or voracious black holes. Darker shades in the image on the left correspond to dimmer parts of the background glow, while yellow and white show the brightest light
Read the entire article here
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| Originally posted by Omega_M That was how they proved the Big Bang theory. |
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| Originally posted by Q5echo well, not trying to be smart ass, but why is it still called a theory? what the guys you're talking about did was reinforce the current "cosmological paradigm" within the community. |
IOW, no better scientific explaination for the expansion itself, but the origin is another question?
Of course not. What makes you think I'm saying it's another question ? Besides, proof of big bang does not mean that all the questions about the origin have been answered.
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| Originally posted by Omega_M Of course not. What makes you think I'm saying it's another question ? Besides, proof of big bang does not mean that all the questions about the origin have been answered. |
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| Originally posted by DJ Shibby I think that our current theories are unable to determine yet what actually happens out there in the void, and we keep building on TOP of old theories, instead of taking steps backwards to rectify errors. The reason we can't do this is most likely because our system of arithmetic itself may be the root of the problem, disallowing the cohesion of absolute information and theoretical inquery. So yeah... we can't actually ascertain the weight of galaxies and solar systems, so we sloppily make up a variable, "dark matter", to encompass everything that we don't yet understand or doesn't fit correctly into our models. |
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| Originally posted by Renegade First of all "dark matter" is not just a "variable" that has just been arbitrarily "made up" by astrophysicists to compensate for their "sloppy" arithmetic. The cohesion of galaxies indicates that they are bound by a gravitational force that far exceeds what we would expect given the amount of baryonic matter within them (I believe that there is only about 4% of the baryonic matter necessary to sustain the sort of structures that galaxies arrange themselves in). If this is the case, then there are basically two options: either our theory of gravity is wrong, or there is some unseen element that accounts for the missing gravitational force. You seem to favour the first option. That is, that either our assumptions about the gravitational constant are wrong or that gravity somehow behaves differently on scales as large as those of galaxies (which would constitute sloppy arithmetical padding were it to be a alternative seriously advanced by astrophysicists). When I say "wrong" here, by the way, I'm not talking about being wrong in our assumptions about gravity by a few minor degrees: I'm talking about being wrong by a factor of about 25. Given how well we can use our current models of gravity to explain the behaviour of bodies on virtually all scales - from the terrestrial to the celestial - the idea that our assumptions about the strength of the gravitational force could be wrong by such a huge factor is simply inconceivable. I understand from other discussions we've had that you fancy yourself as something of a Popperian epistemologist, but your assumption that we could be so fundamentally mistaken about the nature of gravity simply flies in the face of basically all empirical data. If you're going to seriously advcance the idea that our arithmetic concerning gravity is so fundamentally flawed, then I'd be interested to hear how it is you think that we can accurately predict the orbital paths and speeds of all orbiting bodies (tiny perturbations in these predictions allowed us to postulate the existence of Pluto before it was discovered - or was that just a "sloppy" variable too?) or send probes successfully to Neptune. Perhaps our theory of gravity could turn out to be wrong, but there is no possible way that it could turn out to be wrong enough to account for the stability of galaxies without introducing some previously unknown element. As for dark matter itself, its introduction to the equation says nothing about its nature. We don't know whether it's baryonic matter (almost certainly not), whether it is affected by the electromagnetic or nuclear forces (most likely not) or how much of it - in terms of volume - actually exists (we have no idea). At the moment it's still just a theoretical particle, but then so were all other particles at one point: everything on the scale of the molecule, down to the atom, to the baryons and leptons, all the way to level of the quark were all just abstract equations before their existence could be empirically demonstrated in a laboratory setting. I suspect that in the next decade or so, exactly the same will be made true with regards to so-called "dark" matter. |
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| Originally posted by Omega_M Physics is based on solid experimentation. It is not hypothetical or empirical. |
Actually I saw a doco on radiation the other day on telly, about the re-evaluation of the effects of things like Chernobyl which had a fairly convincing arguement in terms of a lot of the hazards being 'overstated' by fairly much all the scientific community.
http://news.bbc.co.uk/1/hi/sci/tech/5173310.stm
Sadly doesnt exist on google.vids or anything yet.
Aside from that, rest of the thread may as well be in chinese to me.
And no Shibby, not everyone can be a scientist. Especially me!
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| Originally posted by DJ Shibby Are you fucking kidding me? |
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| The problem with people today is that they put so much faith in the current models that they don't realize that there are any number of similar models that could work just the same but which would answer other problems. |
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| Also, anyone can be a scientist, so don't throw elitist bullshit at me. If you can perform experiments and come up with (often) testable ideas then you can be a scientist. |
Come on, how hard is it ? But why can't everybody become a philosopher ? | quote: |
| The problem is that our modern world (read: us, our tendency for habit and comfort) has turned us into nonthinking drones lacking creativity and common sense. We are sent to school so that we can learn the exact same methods and theories that have been determined to be "true", we get out of school and work as nonthinking drones in labs. |
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| I'm reading a chemistry book at the moment from 1902; it's fantastic. The best part is that I can see how people thought and felt about science -- alchemy and chemistry -- before the big world wars and before the population boom and before the new model of chemistry arose (READ: NEW as in... the Greeks thought it up and our backwards christian world delegated its logical genius to the backburner for 2000 years...). Yeah, I'm talking about atoms.It's also cool because it's the critical transitional period between romantic magic and solid scientific fundamentalism, objective observations fit into the ephemeral models we build to explain those phenomena. |
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| The only thing a person needs to be a good scientist is to question everything. |
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