io9: dark matter

Dark Matter Lab Dedicated 5,000 Feet Underground

Stephen Goldmeier — Tue, 23 Jun 2009 14:08:19 PDT

This week, the Sanford Lab dedicated an underground science fortress to research dark matter. The lab is 5,000 feet underground in the mountains of South Dakota, shielded from cosmic radiation.

The lab is on a site that used to do physics research, and was a gold mine before that. The current Sanford Lab, in collaboration with the Deep Underground Science and Engineering Laboratory (DUSEL), is the deepest underground lab in the world. It's divided into three levels: the shallow lab, the mid-level, and the deep campus. The deep campus is 6 and a half Empire State Buildings deep, or around 8,000 feet.

Experiments are already underway at the 5,000 foot level, but the lab intends to run its dark matter experiments as deep as possible in a lab called the Xenon detector experiment, or LUX. Doing the experiments deep inside the earth isn't just a demonstration in mad science; it's also a way to keep out interfering cosmic radiation.

The effects of dark matter in these experiments are so minuscule that any interfering radiation could throw off any experiments done at ground level. To get any real data, these experiments require a lot of shielding. Thousands of feet of earth should do the job just fine.

This $550 million project should be up and running by 2016. And soon after, it'll probably make it's SyFy channel debut as the site of a big-budget underground disaster movie!

Sanford Lab dedicated 4,850 feet underground [Sanford Lab, via Physorg]

(Top image: a 3D map of the universe's dark matter, from NASA, ESA and R. Massey. Bottom image: Zina Deretsky, National Science Foundation)

Galactic Cluster Collision Divides Ordinary Matter from Dark Matter

Ed Grabianowski — Fri, 29 Aug 2008 08:00:00 PDT

Almost six billion years ago, two of the largest gravitational structures in the universe slammed into each other with velocities in the millions of miles per hour. Galactic clusters are collections of galaxies (sometimes thousands of them) that seem to hang together in violation of the known laws of physics. Not only did this ancient collision result in a stunningly beautiful image, but it's given astrophysicists an important clue about the nature of dark matter.

The image above is a composite, combining data from the Hubble Space Telescope with x-ray imagery from the Chandra X-Ray Observatory. Hubble captured the blue areas by detecting the gravitational lensing of light shining around the cluster. Dark matter in the cluster is causing the lensing. The pink area is a mass of hot gas, made of ordinary matter, which radiates the x-rays detected by Chandra.

What's amazing about the image is how clearly it shows that the dark matter separated from the ordinary matter when the clusters collided. The gases interacted with each other gravitationally, causing them to slow down and "pile up" in the middle of the clusters. The dark matter evidently did not interact with itself, sliding to the outer edges of the clusters. Astronomers think the mass of all this dark matter is what holds clusters together - without it, the galaxies are moving too fast to stay together. The cluster collision provides a lot of direct evidence that dark matter exists. Image by: NASA/ESA.

You can see the full image in high-resolution here.

Collision of galaxy clusters captured by astronomers. [EurkeAlert!]

Could a Fictional Character Win the Nobel in Physics?

Annalee Newitz — Mon, 14 Apr 2008 15:46:46 PDT

Opening in select U.S. theaters over the next few weeks, Dark Matter is a movie about physics gone wrong. No, the Hadron Collider doesn't punch a hole in reality. Instead, it's about a much smaller and more personal explosion that occurs when a young Chinese graduate student named Liu Xing comes to the U.S. to study cosmology, and finds out that science isn't about truth but politics. Based on a true story, Dark Matter explores what happens when Liu Xing's radical theories of dark matter in the early 1990s clash with those of his academic adviser. When he refuses to toe the line, his adviser disowns him and Liu Xing hurtles towards personal destruction. The premise is intriguing, and writer Billy Shebar based his main character's ideas on real theories about superstrings.

Shebar claims that the "dark matter particle" predicted by Liu Xing could turn out to be "the real dark matter present in the universe." If so, Shebar boasts, "he could become the first fictional character to win a Nobel Prize."

While those claims may be a little far-fetched, the film itself sounds like one of those rare moments where fiction about scientists turns out to be as strange and haunting as science fiction. Though not as surreal as Darren Aronofsky's Pi, the flick deals with some of the same clashes between science-for-truth and science-for-prestige. Check the Dark Matter site for details about when it will be coming to your city.

Dark Matter [official site]