Dark-matter search plunges to new depths

U. CHICAGO (US)—Researchers are expecting a bubble chamber more than a mile underground will reveal dark matter’s secret identity.

Scientists are deploying a 4-kilogram bubble chamber at SNOLab, part of the Sudbury Neutrino Observatory in Ontario, Canada, in anticipation that dark matter particles will leave bubbles in their tracks when passing through the liquid in one of the chambers.

A second 60-kilogram chamber will follow later this year.

Dark matter accounts for nearly 90 percent of all matter in the universe. Although invisible to telescopes, scientists can observe the gravitational influence that dark matter exerts over galaxies.

“There is a lot more mass than literally meets the eye,” says Juan Collar, associate professor of physics at the University of Chicago. “When you look at the matter budget of the universe, we have a big void there that we can’t explain.”

Likely suspects for what constitutes dark matter include WIMPS (Weakly Interacting Massive Particles) and axions.

Theorists originally proposed the existence of both groups of subatomic particles to address issues unrelated to dark matter.

“These seem to be perfect to explain all of these observations that give us this evidence for dark matter, and that makes them very appealing,” Collar says.

SNOLab will be the most ambitious in a series of underground locations, Collar says. In 2004, he and colleagues established the Chicagoland Observatory for Underground Particle Physics (COUPP) at Fermi National Accelerator Laboratory.

“We started with a detector the size of a test tube and now have increased the mass by a factor of more than a thousand,” says Andrew Sonnenschein, a physicist at Fermilab.

“It’s exciting to see the first bubble chamber being sent off to SNOLab, because the low level of interference we can expect from the cosmic rays there will make our search for dark matter enormously more sensitive.”

COUPP extends to the city of Chicago’s flood-control infrastructure, called the Deep Tunnel.

The city has granted COUPP scientists access to the tunnel, 330 feet underground, to test prototypes of their instruments. The collaboration also tested instruments in a chamber 350 feet below Fermilab, and in a sub-basement of the Laboratory for Astrophysics and Space Research on the UChicago campus.

The troublesome underground radiation sources consist of charged particles that lose energy as they traverse through a mile or more of rock. But rock has no impact on particles that interact weakly with matter, such as WIMPS, thus the move to Sudbury.

“SNOLab is a very special, spectacular place, because the infrastructure that the Canadians have developed down there is nothing short of amazing,” Collar says.

“Even though SNOLab sits atop a working nickel mine, conditions there are pristinely antiseptic.

Collar also is a member of the Coherent Germanium Neutrino Technology (CoGeNT) collaboration, which operates a detector that sits nearly half a mile deep at the Soudan Underground Mine State Park in northern Minnesota.

The 60–kilogram detector that Collar and colleagues will install at SNOLab later this year, meanwhile, undergoes testing in a tunnel 350 feet beneath Fermilab.

“Most of us have been concentrating on intermediate-mass WIMPS for decades,” Collar explains.

“In the last few years the theoreticians have been telling us more and more, look, under these other sets of assumptions, it could be a lighter WIMP. This device is actually the first of its kind in the sense that it’s targeted specifically for light WIMPS. We’re seeing interesting things with it that we don’t fully understand yet.”

Collar estimates that it’ll take a decade or more for physicists to become completely convinced that they’ve seen dark-matter particles.

“It’s going to take a lot of information from very many different points of view and entirely independent techniques. One day we’ll figure it out.”

Researchers from Indiana University contributed to the study.

More news from University of Chicago: www-news.uchicago.edu

chat5 Comments


  1. divineadvancedhumanbeings.com

    First of all, there is no such thing as black holes! There is only misunderstanding about how stars and their systems move in space. When scientists finally understand how our own planet moves around the sun in a downward spiral orbit while our sun moves down through space in a shallow orbit; then they will begin to understand the relative motion of the other star systems, which are moving toward us and away from us and in all directions. When we learn how particles move through space, which includes the sun and its orbiting planets, we will then, understand much more about this machine we call the universe.

    Particles in space are always moving in a spiral orbit moving from low pressure to high and then back again. However, this pressure exists not just from the outside pushing in but also from the inside pushing out. Understanding these pressures and how they work is the heart of “other dimensional science.” Understanding how these star systems move through space, will also accurately answer the questions of red giants and white dwarfs, as well as…the death and birth of stars, which do not exist.

    It is true that stars get bigger and smaller as they orbit from one pressure zone to another and consequently, they do change color as a result, but stars do not nova and then disappear. I would love to view a star nova through a powerful telescope, a star nova is a spectacular thing to see but when it’s all over with, that star is still there, we just can’t see it any longer because it has moved from one pressure spectrum to another!

    Currently, the earth is orbiting down from low pressure into high pressure. It takes 12,000 years to complete this quarter cycle before we enter, into the next cycle, which will take us once again… from relative low pressure to high, and we begin another 12,000 year cycle.

    The earth and the machinery which surrounds it, work a lot like a washing machine or any machine, for that matter. When you have working parts, the parts of the machine get hot in certain places and so the machine changes gears. It all works like a clock in a way. Pressure builds up and finally moves the minute hand into the next position. This explains the motion of the poles which are shifting, the rising of water, which result in major floods and often permanent water displacement, volcanoes, earth quakes, hot and cold cycles, etc.…

    There comes a point where we reach the end of a cycle when the earth is at the maximum internal pressure which exists at the quantum level of space, and it must let that pressure go. It reacts much like a spring that has been wound so tight that it finally let’s go. When this happens… particles, which are attached to one another in long chains, expand rapidly, which causes everything on the earth to expand just a bit; the greatest effect is in the waters of the earth.

    Now, the sun is also under great pressure and when we reach the end of a cycle, the sun which has been compressed changing colors as it goes through the different pressure spectrums, expands rapidly. This effect, like the water of the earth, affects the sun in the same manner because of its molten nature. The visual effect is much more spectacular when the sun once again, regains homeostasis. However, we do not see it as it has passed into the next cycle hidden by a blanket of electrons. These huge electron conduits, separate one macro particle structure from another.

    Scientists will learn and understand this in the next few years as they continue to put particles under extreme pressure in the laboratory but will understand much more when they discover how to get a frequency signal inside of an electron conduit. When they can overcome the pressure of what I call E. Space and get a frequency signal inside, they will then be able to map the structure of an atomic particle which works exactly the same way as our solar system. Eventually, they will also understand “other dimensional particles” and how they fit into the machine and why.

  2. zcjk02

    I casually follow articles like this. Since we’re going a mile below the surface instead of space, is it thought that dark matter surrounds all of us right now? Are WIMPS and axions particles that reside in mass around us?

  3. Steve Koppes

    Yes, there are a lot of WIMPS around, assuming they exist.

  4. josh


  5. Mr. A

    I visited Divines website and have to agree with josh. This new theory might be worse than creationism….

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