Physicists Renew Claim, in New Experiment, of Detecting Dark Matter Particles

NY Times ^ | April 17, 2008 | DENNIS OVERBYE

[neverdem]

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. “No other experiment whose result can be directly compared in a model-independent way is available so far,” she said. The findings increase the chances that the modulation is real, outside dark matter experts say.

Dark matter has taunted astronomers and physicists ever since the astronomer Fritz Zwicky of the California Institute of Technology pointed out in the 1930s that clusters of galaxies appear to be missing enough visible matter to hold them together gravitationally. Speculation has centered on the possibility that the dark matter consists of hypothetical elementary particles left over from the Big Bang — so-called WIMPs, or weakly interacting massive particles, that are immune to most forces of nature and so can pass through us and the Earth like ghosts.

The Dama team uses sodium iodide, which flashes light when a WIMP smashes into it, as a detector. The first experiment, which ran from 1996 to 2002, had 220 pounds of sodium iodide; the second — which...

[neverdem]

Stem cell use may lead to human applications

Mounting Evidence Shows Red Wine Antioxidant Kills Cancer resveratrol again

FReepmail me if you want on or off my health and science ping list.

[Telepathic Intruder]

Theoretically, particles can exist that are not affected by any of the known forces. Nuetrinos are only weakly interacting, which means that only the weak nuclear force can affect them, making them the most elusive particles that can be detected. They are extremely low-mass however, not heavy enough to account for dark matter. Particles that are not affected by any of the known forces, except gravity, would be essentially “ghost particles”. There would be no way to detect them except fot their gravitational influence.

[Captain Beyond]

bump

[shadowgovernment]

“Particles that are not affected by any of the known forces, except gravity, would be essentially “ghost particles”. There would be no way to detect them except fot their gravitational influence.”
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make far enough away, small enough, or back millions of years and you can publish anything you wish..Scams by any other name are Scams..who can dispute Dark matter as there is no way to detect it?? ans: I can, this is baloney. can I get a federal $$ grant to study my theory: The universe is here because G_D thinks it is and he is the “Matter” that holds the universe together..I'll get a grant about as easy as Scientists who disparage Man made global warming.

[Caramelgal]

…make far enough away, small enough, or back millions of years and you can publish anything you wish..Scams by any other name are Scams..

And at one time we didn’t have telescopes strong enough to physically observe other solar systems and planets but astronomers theorized that they existed. But I guess that was all a scam….

[Telepathic Intruder]

he is the "Matter" that holds the universe together

I suppose it depends on how you choose to percieve God. If he is everything, then whatever you look at is only a part of him. There is a difference, however, in how I percieve God and how I percieve the universe. One is the creator, another is the creation. And a clock created by God might still be able to tick without him having to cause each tic; he just needs to wind it up.

[SunkenCiv]

Thanks neverdem.

[RightWhale]

evidence of the putative particles

They are looking for dark matter particles and their machine has given some readings so they must be of dark matter particles. Sure, we can just accept that. No problem and Pres Putin is busy with his gymnast right now so he won't miss his putative particles.

[shadowgovernment]

“And at one time we didn’t have telescopes strong enough to physically observe other solar systems and planets but astronomers theorized that they existed. But I guess that was all a scam….”
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the history of how science is funded is an interesting topic, today we have a system of grants (tax money) with gate keepers awarding the money without much oversight..
Politics and fads (man made global warming) and save the planet fads have sucked money from basic research that is practical (think Tom Edison as an example)..and has resulted in so called science justifying the death of the incandescent light bulb via legislation..the implications
of scams in science are obvious.