U study reveals more about dark matter

Ethan Nelson

Dark matter might not be as obscure as astronomers once thought.
 
The nebulous substance that makes up more than 85 percent of the universe’s mass may interact with itself, rather than exclusively with gravity like research previously explained, according to a University of Minnesota study published last week.
 
University astrophysics professor Liliya Williams and an international team of researchers found clumps of dark matter lagging behind others in a group of galaxies, which could be the result of friction between particles of dark matter. If that’s the case, researchers now know more about the mysterious matter.
 
The study’s results aren’t definitive and need further study, though it could nix several theories about dark matter’s origin and properties, including a well-known theory that suggests it interacts with next to nothing.
 
Williams said the most accepted model that explains the properties of all matter, known as the Standard Model, can’t explain the researchers’ findings.
 
Most evidence points to dark matter being composed of particles, she said, which means it could be detected within the Earth’s atmosphere
And researchers hope to capture it.
 
University researchers are hoping dark matter will excite germanium or silicon particles enough for them to detect it in a lab setting, an experiment which University professor Priscilla Cushman is trying to do in the school’s Soudan Underground Laboratory in northern Minnesota.
 
Williams’ team used images from the Hubble Space Telescope and an observatory in Chile to view a galaxy cluster 1.4 billion light-years away. 
 
Her method is one of three approaches to studying dark matter. The others include smashing particles together and detecting dark matter in a lab — the method Cushman plans to use.
 
Cushman said scientists have yet to detect the matter in a lab setting, but Williams’ findings could potentially change how the universe is viewed.
 
“An effect like this has to be something totally new,” Cushman said.
 
Dark matter can’t be seen with the naked eye, so researchers observe the light that galaxies bend around themselves — an effect called gravitational lensing — to examine it.
 
Other researchers are conducting their own studies on dark matter.
 
Another international team created a map of dark matter this month, and the Large Hadron Collider in Switzerland is beginning to search for dark matter.
 
Despite all of the work being done to make sense of dark matter, scientists still don’t know a great deal about its properties.
 
“We know very little,” said University astronomy professor Keith Olive. “We know it should exist.”