2007 May 2007 (Discover Magazine): No web copy available


Particle no-show pans former find

Geoff Brumfiel; Published May 6, 2004 (Nature)
The most powerful search yet for the Universe's missing matter has come up empty handed, contradicting an earlier study that claimed to have seen new particles.

Researchers from the Cryogenic Dark Matter Search II (CDMSII) say they are pleased with their first results, which show that their detector is working and set new constraints on how the so-far undetected matter can behave, if it exists.

For decades, physicists and astronomers have known that conventional particles of the type that make up atoms, stars and people only account for a tiny fraction of the Universe's mass. The rest of the mass is referred to as dark matter, as its identity is unknown. It is thought to come from a variety of heavy particles that rarely interact with regular matter and can pass through conventional objects unseen.... Read more at Nature

Dark matter detector limbers up

Dr David Whitehouse; Published May 5, 2004 (BBC News)
A US team has released the first results from a super-sensitive hunt for the mysterious "dark matter".

This form of matter comprises more than 70% of the Universe's mass, far more than the stars and galaxies we can see.

The Cryogenic Dark Matter Search uses equipment at the bottom of a Minnesota mine to filter out all interference.

Writing in the Physical Review Letters, the team says that while a detection has yet to occur, there is now a better idea of how much dark matter must exist... Read more at BBC News

Missing Matter... Still Missing

Timothy; Published May 5, 2004 (Slashdot)
"Nature.com, PhysicsWeb, and the BBC all report on the latest results from the Cryogenic Dark Matter Search. 'The most powerful search yet for the Universe's missing matter has come up empty handed, contradicting an earlier study that claimed to have seen new particles.' 'A favoured theory is that the dark matter consists of Wimps (weakly interacting massive particles) about a thousand times more massive than a proton, one of the particles found in an atom's nucleus... on the rare occasions a Wimp strikes an ordinary atom, the effect should be noticeable.' 'Writing in the Physical Review Letters, the team says that while a detection has yet to occur, there is now a better idea of how much dark matter must exist.' They 'hope to improve the sensitivity of the experiment by another factor of 20 over the next few years.' What's 20 times 0? And don't tell me zero!" Read more at Slashdot

Dark Matter Still Elusive

Charles Seife; Published May 4, 2004 (Science)
DENVER--Dark matter has just become a shade darker. Physicists have presented the first results of a high-tech search for the invisible particles of dark matter that theorists believe make up most of the mass in the universe. Even though the new instrument is much more sensitive to dark matter than previous ones, it failed to get even a tiny glimpse of the elusive dark matter particle. The finding nails shut the coffin on the controversial claim to have spotted dark matter, but it makes the no-show particle an even more troubling hole in scientists' understanding of our universe. Read more at Science

May 4, 2004 (Washington Times): No web copy available


Scientists Doubting Discovery of New Dark Matter in Space

James Glanz; Published February 23, 2002 (New York Times)
MARINA DEL REY, Calif., Feb. 22 - Two years ago at a scientific meeting here, a team of physicists based at the University of Rome shook the world of physics by announcing that they had made what would have been one of the greatest discoveries in the history of science: a detection of particles that may flit through space almost unnoticed, in such numbers that they make up most of the mass of the universe.

Today, that claim came close to dying a quiet death as three separate groups, including one at Stanford University, said that despite their best efforts, they had been unable to find the so-called dark matter particles suggested by the Rome experiments.

"To tell you the truth, I don't think a lot of people believe the results," said Dr. Olivier Martineau of the Institute for Nuclear Physics in Lyon, France, who is working on a dark matter experiment called Edelweiss in the French-Italian Alps. He and his colleagues have seen no sign of the particles.... Read more at New York Times


Astronomers find clues to elusive dust

David Perlman; Published March 23, 2001 (San Francisco Chronicle)
For 70 years astronomers have puzzled over one of the great mysteries in the universe: What keeps our galaxy -- indeed all galaxies -- spinning like pinwheels, and what prevents them all from flying apart?

The scientists have calculated the mass of all the visible stars and gas in the galaxies, and find that there isn't nearly enough observable matter in them to exert the gravitational force that's needed to hold everything together.

So somewhere, they reason, the galaxies must contain vast quantities of invisible material -- something astronomers have long called the "missing mass, " or the "dark matter," of the universe.... Read more at San Francisco Chronicle


Darkest Puzzle of the Cosmos

Usha Lee McFarling; Published March 20, 2000 (Los Angeles Times)
PALO ALTO--It's happening again. Some physicists are claiming to have solved the greatest mystery in the universe
They say they have found "dark matter"--impossibly elusive particles that make up nearly all of the universe, yet have never been captured, created in a lab or even detected.
Previous claims have popped up regularly since the early 1980s. But as the charmingly named dark-matter candidates--neutrinos, monopoles, MACHOs, black holes and dwarfs of various colors--fail to stand up to experimental and theoretical proofs, they fade faster than presidential campaign promises... Read more at Los Angeles Times

February 29, 2000 (Boston Globe): No web copy available

In the Dark Matter Wars, Wimps Beat Machos

James Glanz; Published February 29, 2000 (New York Times)
MARINA DEL REY, Calif., Feb. 27 -- The last hopes for a universe filled with familiar stuff behaving in comprehensible ways died here in Los Angeles County last week. It showed in the head-turning attire of at least two of the scientists who carried the news to a major conference on cosmology in a hotel across the street from a restaurant called Killer Shrimp.

But never mind the shrimp. Dr. Joel Primack spoke about the overall contents of the universe while wearing a midnight blue jacket and a tie that bore the likeness of Van Gogh's "Starry Night," in which some ominous presence between the stars overwhelms the visible bodies themselves. In her own talk, Dr. Katherine Freese heralded "The Death of Baryonic Dark Matter" in an all-black pantsuit.

Baryons are the ordinary particles, like protons and neutrons, of which stars, asteroids, comets, planets, people and textiles are made. By measuring the gravitational pull of some unknown "dark matter" on the visible stars and galaxies, astronomers have determined that this mysterious material which seems to permeate the universe has a weight that is 60 times that of the stars and 7 times that of all baryons, including gas and solid material in space.... Read more at New York Times

February 29, 2000 (Stanford University Press Release): No web copy available

New cryogenic detectors probe recent evidence for dark matter particle

Robert Sanders; Published February 29, 2000 (UC Berkeley News On-Line)
A new generation of particle detector that operates at temperatures near absolute zero has proven extremely accurate in identifying the particles that crash through it, an international team of scientists reported last week.

The novel detector, buried 35 feet underground on the Stanford University campus, has dedicated itself for more than a year to the search for exotic and elusive particles that, according to some theories, make up more than 90 percent of the mass of the universe.

Though the device has yet to find evidence of such particles - known collectively as WIMPs, or weakly interacting massive particles - it has proved to have a keen ability to discriminate between the different kinds of particles that zip through it.... Read more at UC Berkeley News On-Line

Matter Mystery May Be Coming Out of the Dark

Curt Suplee; Published February 28, 2000 (Washington Post)
After four years of searching, an Italian-Chinese research team may have finally detected one of the most fervently sought commodities in modern science: a particularly weird form of the invisible "dark matter" that makes up at least 90 percent of everything in the cosmos.

"If it's true, it's exceedingly important, and would shed light on how galaxies formed in the early universe," said astrophysicist Virginia Trimble of the University of California at Irvine and the University of Maryland.

Indeed, many physicists would regard a definitive sighting of the coveted dark-matter candidates called "WIMPs"--for weakly interacting massive particles--as guaranteed to win a Nobel Prize.... Read more at Washington Post

Experiments at Stanford Shake Dark-Matter Claim

James Glanz; Published February 26, 2000 (New York Times)
MARINA DEL REY, Calif. Feb. 25 - A team of physicist announced today that a highly sensitive experiment at Stanford University to detect the so-called dark matter particles that could account for most of the mass in the universe had contradicted a stunning and controversial announcement by a team of Italian and Chinese physicists last week that they had detected the elusive particles... Read more at New York Times

As 2 Efforts to Find 'Dark Matter' Clash, Mystery of Universe Remains

Faye Flam; Published February 26, 2000 (Philadelphia Inquirer)
Scientists have searched for years forevidence of "dark matter," invisible particles that are believed to make up far more of the universe - from here to there to everywhere - than what we can actually see.

Astronomers are sure it exists because they can see its effects millions of light-years away. Out there, a giant sea of dark matter appears to exert a gravitational pull strong enough to move whole galaxies, like so many leaves swept along in a current. Particle physicists have predicted that it would be found on Earth in the form of new particles that exhibit the requisite slippery properties of the dark matter. They fancifully namedthem WIMPs, for Weakly Interacting Massive Particles. Entire careers have been spent trying to find WIMPs caught in devices built for millions ofdollars in England, France, German, Italy and the United States.... Read more at Philadelphia Inquirer

February 19, 2000 (New York Times): No web copy available

February 16, 2000 (New York Times): No web copy available

This work is supported by the National Science Foundation and the Department of Energy