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DAMA/Libra claim confirmation of direct dark-matter detection |
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| Apr22-08, 05:00 AM | #1 |
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DAMA/Libra claim confirmation of direct dark-matter detection
A recent newspaper story by Dennis Overbye in the New York Times
http://www.nytimes.com/2008/04/17/sc...ce/17dark.html (probably needs signup-for-user-tracking-registration to view) and elsewhere http://www.iht.com/articles/2008/04/...ience/dark.php reports that A team of Italian and Chinese physicists on Wednesday renewed a controversial claim that they had detected the mysterious dark matter particles that astronomers say swaddle the galaxies in halos and direct the evolution of the universe. The team, called Dama, from "DArk MAtter," and led by Rita Bernabei of the University of Rome, has maintained since 2000 that a yearly modulation in the rate of flashes in a detector nearly a mile underneath the Gran Sasso mountain in Italy is the result of the Earth's passage through a "wind" of dark matter particles as it goes around the Sun. Other groups of hunters of dark matter have just as consistently failed to find any evidence of the putative particles. At a meeting in Venice, Dr. Bernabei reported that a new, bigger experiment named Dama/Libra had now observed the same modulation. Can anyone point to a more technical account of the claim? Is there a preprint out? -- -- Jonathan Thornburg <J.Thornburg@soton.ac.uk> School of Mathematics, U of Southampton, England "It is especially difficult to find exact solutions of the equations, as the equations are nonlinear." -- Einstein, fall 1913, discussing nonlinear gravitational radiation with Born (quoted in MTW chapter 35) |
| Apr23-08, 05:00 AM | #2 |
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I asked if anyone had more technical info on the DAMA/Libra claim of
a direct dark-matter detection. To follow up on my own query :), here are some pointers I've found in the last day-and-a-half: * Details of the claim: http://arxiv.org/abs/0804.2741 * Non-technical overview (I think lacking a suitable degree of skepticism) at Bad Astronomy: http://www.badastronomy.com/bablog/2...tter-detected/ * Criticism by doriga at http://dorigo.wordpress.com/2008/04/...-libra-result/ * Strong criticism by Juan Collar at Cosmic Variance: http://cosmicvariance.com/2008/04/21...ter-detection/ ciao, -- -- "Jonathan Thornburg [remove -animal to reply]" <J.Thornburg@soton.ac-zebra.uk> School of Mathematics, U of Southampton, England "ActiveX as a security component? Isn't that like Ben and Jerry's ice cream as a diet component?" -- Bill Unruh, sci.crypt, 18.Jul.2003 |
| Apr23-08, 05:00 AM | #3 |
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Hello.
I know - there is April now - so it's good time for various, crazy proposals. Anyway the whole idea does not looks mad enough for me in order to be considered true. Physics is an empirical science. If you claim something - you have to prove your claims experimetally. I am highly sceptical in that issue you've just described. Only new approach, new experiment proposals, carefull consideration if those exp make sense and realization of the most interesting ideas can push our knowledge forward. Regards Pawel Karwowski On Apr 21, 10:44 pm, "Jonathan Thornburg [remove -animal to reply]" <J.Thornb...@soton.ac-zebra.uk> wrote: > A recent newspaper story by Dennis Overbye in the New York Timeshttp://www.nytimes.com/2008/04/17/science/space/17dark.html > (probably needs signup-for-user-tracking-registration to view) > and elsewherehttp://www.iht.com/articles/2008/04/17/healthscience/dark.php > reports that > A team of Italian and Chinese physicists on Wednesday renewed a > controversial claim that they had detected the mysterious dark > matter particles that astronomers say swaddle the galaxies in halos > and direct the evolution of the universe. > > The team, called Dama, from "DArk MAtter," and led by Rita Bernabei > of the University of Rome, has maintained since 2000 that a yearly > modulation in the rate of flashes in a detector nearly a mile > underneath the Gran Sasso mountain in Italy is the result of the > Earth's passage through a "wind" of dark matter particles as it > goes around the Sun. Other groups of hunters of dark matter have > just as consistently failed to find any evidence of the putative > particles. > > At a meeting in Venice, Dr. Bernabei reported that a new, bigger > experiment named Dama/Libra had now observed the same modulation. > > Can anyone point to a more technical account of the claim? Is there > a preprint out? > > -- > -- Jonathan Thornburg <J.Thornb...@soton.ac.uk> > School of Mathematics, U of Southampton, England > "It is especially difficult to find exact solutions of the equations, > as the equations are nonlinear." -- Einstein, fall 1913, discussing > nonlinear gravitational radiation with Born (quoted in MTW chapter 35) |
| Apr23-08, 05:00 AM | #4 |
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DAMA/Libra claim confirmation of direct dark-matter detection
Jonathan Thornburg -remove -animal to reply- wrote:
> A recent newspaper story by Dennis Overbye in the New York Times > http://www.nytimes.com/2008/04/17/sc...ce/17dark.html > (probably needs signup-for-user-tracking-registration to view) > and elsewhere > http://www.iht.com/articles/2008/04/...ience/dark.php > reports that > A team of Italian and Chinese physicists on Wednesday renewed a > controversial claim that they had detected the mysterious dark > matter particles that astronomers say swaddle the galaxies in halos > and direct the evolution of the universe. > > The team, called Dama, from _DArk MAtter,_ and led by Rita Bernabei > of the University of Rome, has maintained since 2000 that a yearly > modulation in the rate of flashes in a detector nearly a mile > underneath the Gran Sasso mountain in Italy is the result of the > Earth's passage through a _wind_ of dark matter particles as it > goes around the Sun. Other groups of hunters of dark matter have > just as consistently failed to find any evidence of the putative > particles. > > At a meeting in Venice, Dr. Bernabei reported that a new, bigger > experiment named Dama/Libra had now observed the same modulation. > > Can anyone point to a more technical account of the claim? Is there > a preprint out? > RESULTS ON DARK MATTER AND DECAY MODES BY DAMA AT GRAN SASSO http://arxiv.org/abs/0704.3543 First results from DAMA/LIBRA and the combined results with DAMA/NaI http://arxiv.org/abs/0804.2741 Dark Matter search http://arxiv.org/abs/astro-ph/0307403 Rita Bernabei et al Dip. di Fisica, Università di Roma Tor Vergata and INFN-Roma Tor Vergata, 00133 Roma, Italy In regards to DAMA observed annual oscillation, a question comes to mind in terms of the following logic: Given the statement: -- The Milky Way is moving at around 600 km/s with respect to the photons of the Cosmic Microwave Background (CMB). This has been observed by satellites such as COBE and WMAP as a dipole contribution to the CMB, as photons in equilibrium at the CMB frame get blue-shifted in the direction of the motion and red-shifted in the opposite direction. -- and also: -- the solar system is orbiting galactic center at about 200 km/sec -- and also: -- the earth has a velocity of 30 km/sec around the sun. -- and also -- ref: Dark Matter search http://arxiv.org/abs/astro-ph/0307403 Fig 10 Harmonic DAMA/NaI experimental data indicates an annual oscillation of detected radiation flux detected on earth. -- Has anyone done the trigonometry in order to calculate the correlation of annual DAMA/NaI experimental data on earth due to earth_solar annual differential velocity projection to CMB velocity vector? I have found some information to answer the question. Possibly someone could comment. The CMB 'hot spot' or 'wind origin' is in constellation Leo http://aether.lbl.gov/www/projects/u2/ Now the earth moves around the sun at 30 km/sec The hypothesis would be that average flux would be when earth - sun line would be parallel to earth - Leo line which occurs September 1 (sun in Leo) and March 1. with maximum flux (earth against the CMB dipole wind) on December 1 and minimum (CMB dipole wind to earth's back) on June 1. This is 180 degrees out of phase with your data but perhaps that is a reflection of dark matter reality This CMB dipole wind and earth solar rotation are then approximately 180 degrees of phase with data expressed in: http://arxiv.org/abs/astro-ph/0307403 Fig 10 http://arxiv.org/abs/0704.3543 Figure 2 where t0 = 152.5 is June 1 (maximum flux) Is this a coincidence or an indication of connection between DAMA/NaI observed data and CMB dipole wind. Richard Saam |
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