Message boards :
Science (non-SETI) :
Dark matter/Dark Energy
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Author | Message |
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Lynn Send message Joined: 20 Nov 00 Posts: 14162 Credit: 79,603,650 RAC: 123 |
Study says: Earth Might Have Hairy Dark Matter The solar system might be a lot hairier than we thought. A new study publishing this week in the Astrophysical Journal by Gary Prézeau of NASA's Jet Propulsion Laboratory, Pasadena, California, proposes the existence of long filaments of dark matter, or "hairs." Dark matter is an invisible, mysterious substance that makes up about 27 percent of all matter and energy in the universe. The regular matter, which makes up everything we can see around us, is only 5 percent of the universe. The rest is dark energy, a strange phenomenon associated with the acceleration of our expanding universe. http://www.nasa.gov/feature/jpl/earth-might-have-hairy-dark-matter |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
The XENONIT experiment at Gran Sasso National Laboratory has started. It uses 3500 kg of liquid Xenon ccoled at -95 C temperature to look for dark matter. The experiment is managed by the INFN (Istituto Nazionale di Fisica Nucleare) and has as Director Elena Aprile of Columbia University. Another top woman, like Fabiola Gianotti, Director of CERN from next January. Tullio |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
A Chinese Long March D2 rocket has launched a research satellite built by Istituto Nazionale di Fisica Nucleare Italy to search for dark matter. It is called DAMPE from DArk Matter Particles Explorer. Tullio |
Lynn Send message Joined: 20 Nov 00 Posts: 14162 Credit: 79,603,650 RAC: 123 |
A Chinese Long March D2 rocket has launched a research satellite built by Istituto Nazionale di Fisica Nucleare Italy to search for dark matter. It is called DAMPE from DArk Matter Particles Explorer. Thanks for the update tullio :) |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
Maybe I was too enthusiastic after reading a news release of the Istituto Nazionale di Fisica Nucleare. Only one of the four detectors aboard DAMPE for various particle kinds was built and tested in Italy. But what is important is the cooperation between Italian and Chinese scientists. Tullio |
Julie Send message Joined: 28 Oct 09 Posts: 34060 Credit: 18,883,157 RAC: 18 |
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tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
Very interesting article. I happen to know prof. Melchiorri, he was one on my authors when I worked at Edizioni Scientifiche Mondadori in Milano. Now he is a professor in Rome. Tullio |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
The Gran Sasso National Laboratories are starting the XENONIT experiment looking for dark matter particles using a tank containing 3500 kg of liquid Xenon at a depth of 1400 m below the Gran Sasso Mountain. Dark matter particles hitting a Xenon nucleus should emit a flash of light of a particular wavelength and be recorded by detectors. Tullio |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
Is Dark Matter being swallowed up by Dark Energy? Dark energy is the energy ascribed to the Vacuum that is ostensibly causing the universe to expand. Dark matter can be ascribed to possibly particles that we have not yet found. Some suggest neutrinos and so on; but, maybe they are tiny black holes. In any event they are dark because they don't interact with photons. The large black holes that we can infer are there do not account for the apparently missing mass. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
XENONIT at Gran Sasso is looking for WIMPS (Weakly Interacting Massive Particles). If it does not find them the whole story of Dark Matter must be rewritten. But it took thirty years to detect neutrinos. Tullio |
Julie Send message Joined: 28 Oct 09 Posts: 34060 Credit: 18,883,157 RAC: 18 |
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William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
Will dark matter go away if it is assumed that the universe itself is rapidly spinning--if so, then how fast are we spinning? |
Julie Send message Joined: 28 Oct 09 Posts: 34060 Credit: 18,883,157 RAC: 18 |
Will dark matter go away if it is assumed that the universe itself is rapidly spinning--if so, then how fast are we spinning? One half the speed of light, is my thought. The LIGO article on the discovery of gravitational waves leaps to mind. During the final fraction of a second, the two black holes collide into each other at nearly one-half the speed of light and form a single more massive black hole, converting a portion of the combined black holes’ mass to energy, according to Einstein’s formula E=mc2. rOZZ Music Pictures |
Julie Send message Joined: 28 Oct 09 Posts: 34060 Credit: 18,883,157 RAC: 18 |
Will dark matter go away if it is assumed that the universe itself is rapidly spinning--if so, then how fast are we spinning? Blogged something I was pondering over last night.. http://juliedetavernier.wix.com/rozz#!What-about-the-Universal-Spin/d0xmh/56d92b040cf20d226f1e3603 rOZZ Music Pictures |
Lynn Send message Joined: 20 Nov 00 Posts: 14162 Credit: 79,603,650 RAC: 123 |
If not dark energy, what's making the universe expand? "Russian Doll" Galaxy Clusters Reveal Information About Dark Energy Astronomers have used data from NASA’s Chandra X-ray Observatory, ESA’s Planck and a large list of optical telescopes to develop a powerful new method for investigating dark energy, the mysterious energy that is currently driving the accelerating expansion of the universe. The technique takes advantage of the observation that the outer reaches of galaxy clusters, the largest structures in the universe held together by gravity, show similarity in their X-ray emission profiles and sizes. More massive clusters are simply scaled up versions of less massive ones. http://www.nasa.gov/mission_pages/chandra/russian-doll-galaxy-clusters-reveal-information-about-dark-energy.html Space's Deepest Secrets Hunt for Dark Energy EPISODE INFO Meet the scientists across the world on the hunt for dark energy, an unknown form of energy which is hypothesized to permeate all of space and may be accelerating the expansion of the universe. 61 Min. | PG |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
What is making the Universe expand is the Big Bang. What is apparently making the Universe expand faster is also the Big Bang. Let me explain. Suppose you have a balloon with closely spaced dots and you blow it up at a constant rate. As the balloon gets larger and larger the dots will separate from each other at a faster and faster rate even though the input to this process is constant. Apply this thinking to 3 dimensions and you may have yourself an explanation for "Dark Energy". You would think that gravity might eventually slow down the rate of acceleration--maybe it will or already has. |
Gary Charpentier Send message Joined: 25 Dec 00 Posts: 31009 Credit: 53,134,872 RAC: 32 |
What is making the Universe expand is the Big Bang. What is apparently making the Universe expand faster is also the Big Bang. Let me explain. Suppose you have a balloon with closely spaced dots and you blow it up at a constant rate. As the balloon gets larger and larger the dots will separate from each other at a faster and faster rate even though the input to this process is constant. Bad analogy William. As the volume of the balloon gets bigger it goes up with the cube of the radius. So to have space expand at a constant rate you need to be pumping gas into the balloon faster and faster. |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
I didn't say that space was expanding at a constant rate only that the amount of air entering the balloon was constant--what I said was as the balloon gets larger the dots on the balloon move faster and faster. The surface area increases as the square of the radius |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
Yes: Maybe it is slowing down. What we see at the edge of the visible horizon was what was happening 13 billion years ago when acceleration was faster? What do you say ? |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
I say we most likely have less than 10% of the information needed to discover the true nature of the universe. Especially since most of it is made of stuff we call dark energy and dark matter which are names that have been assigned to components we know little or nothing about. Bob DeWoody My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events. |
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