Physicists to discuss dark matters at the Smithsonian
From: symmetrybreaking, Sept. 19, 2008
Scientists know a lot about the 4 percent of the universe that makes up visible matter such as planets and people.
But the other 96 percent remains a mystery.
What makes up that combination of undiscovered matter and cosmic energy, dubbed dark matter and dark energy, poses one of the greatest questions in modern science.
And physicists have ideas about where to find the answer. Astrophysicist Rocky Kolb, of the University of Chicago, and Fermilab particle physics theorist Joe Lykken will explain at a lecture next week in Washington, D.C. , how particle accelerators, satellites, telescopes and underground detectors are preparing to shine light on dark matter and dark energy.
Unraveling that mystery could open the door to a radical new understanding of our universe.
“Dark matter and dark energy are the two most important topics in all of science,” said cosmologist Michael Turner, who will moderate the lecture. Last year at the Smithsonian, Turner moderated a sold-out, lively debate about String Theory, one of the most controversial concepts in particle physics.
Turner, of the University of Chicago, is known for drawing speakers out of their comfort zones with provocative questions.
“He’s a master at it,” said Melody Curtis, senior program coordinator for the Smithsonian Associates. “He brings out the best in people.”
The lecture will be held at 7 p.m. on Wednesday, Sept. 24, at Smithsonian’s National Museum of Natural History. General admission is $20.
Scientists first found evidence of dark matter in 1935. They theorized that clumps of dark matter formed the backdrop to individual galaxies, holding them together as planets and stars formed.
About a decade ago, scientists discovered that an opposite force was pushing the universe apart, expanding its boundaries at an increasing rate. This could be caused by dark energy, Turner said.
“Dark matter and dark energy are the two dark titans that have controlled the evolution of the universe,” he said.
Like dark energy, dark matter has eluded direct detection so far. Other than that, the tow don't seem to have much in common.
“Dark matter is unevenly distributed out there in the universe,” Lykken said. “There’s hunks of it here, and there’s hunks of it over there.
“Dark energy, on the other hand - if it exists at all - is evenly spread out through the whole universe. So there’s just as much dark energy in this office as there is in a same-sized cube out in intergalactic space.”