Dark matter illustrated as a darkly colored substance strung throughout a large, sample expanse in the universe, with heavier concentrations colored black and thinner concentration rendered in light gray. Normal, luminous matter appears clustered into glowing galaxies and galaxy clusters found along the filaments of the dark matter cosmic web. (Image Credit: AMNH/KIPAC/SLAClab/Stanford)
Dark matter is a theoretical type of matter thought to comprise about 80 percent of all matter in the universe. Unlike the "normal" matter that makes up stars, the Earth and everything recognizable in daily life, dark matter is completely invisible. The only way dark matter is known to interact with normal matter is through the force of gravity. One way astrophysicists originally inferred dark matter's existence decades ago was by measuring the rotation rates of galaxies, finding that the gravity generated by available visible matter is insufficient to keep galaxies from flying apart. Further evidence for dark matter comes from "gravitational lensing," wherein unseen dark matter in clusters of galaxies gravitationally warps the fabric of space, causing light from background objects to bend and magnify. Leading models of cosmology indicate dark matter has played a key role in building up the weblike structure of galaxies throughout the universe. Scientists have proposed several hypothetical particles that could compose dark matter and that might fit into the framework of particle physics, called the Standard Model. The hunt for signs of the dark matter particles is taking place in special detectors deep underground, particle accelerators, and radiation beaming from space.
The prevailing view of the universe has just passed a rigorous new test, but the mysteries of dark matter and dark energy remain frustratingly unsolved. Three astrophysicists—Scott Dodelson, Risa Wechsler and George Efstathiou—discuss the implications.
On October 6, The Kavli Foundation hosted a Google+ Hangout to learn more about proposed High Definition Space Telescope, a kind of "Super Hubble" that could launch in the 2030s. We spoke with two of the proponents: Julianne Dalcanton of the University of Washington and Marc Postman of the Space Telescope Science Institute. This is a transcript of that discussion.
On October 6, The Kavli Foundation hosted a Google+ Hangout to learn more about proposed High Definition Space Telescope, a kind of "Super Hubble" that could launch in the 2030s. We spoke to Julianne Dalcanton of the University of Washington, who co-chaired the committee that put forward the proposal, as well as committee member Marc Postman of the Space Telescope Science Institute.
Two astrophysicists and a theoretical physicist discuss how the Large Synoptic Survey Telescope will probe the nature of dark matter and dark energy by taking an unprecedentedly enormous scan of the sky.
The NSF Physics Division hosted a live hour-long Google Hangout with Michael S. Turner, director of the Kavli Institute for Cosmological Physics (KICP). Turner will be joined by other members of KICP to talk about the exciting science going on at the institute including research on the cosmic microwave background and dark matter.
Fresh from the January Rossi Prize Lecture, the scientists who discovered the “Fermi bubbles,” two of the largest structures in the Milky Way, say the bubbles can tell of our galaxy’s past – and even help find dark matter.
Scientists working on the three newest dark matter experiments are hopeful that we’ll soon understand a quarter of the universe – but they’re making no promises.
Three recently funded dark matter experiments have a good shot at glimpsing these long-sought particles. Three scientists on these projects debate the state of the hunt for dark matter, discuss the status of their experiments, and answer your questions.
Three new dark matter experiments are moving ahead with funding from the U.S. Department of Energy and the U.S. National Science Foundation — will one of them finally capture a glimpse of the universe's most elusive material?