- News Home
27 November 2013 12:59 pm ,
Vol. 342 ,
The new head of the National Center for Science Education promises to "fight the good fight" against attacks on...
Analyses of the H7N9 strains isolated from four new cases show that the virus is evolving rapidly, heightening anxiety...
In 2009, Jack Szostak shared a Nobel Prize for his part in discovering the role of telomeres, the end bits of...
Science has exposed a thriving academic black market in China involving shady agencies, corrupt scientists, and...
Paper-selling agencies flourish in the aura of reputable businesses. For some scientists, it may be difficult to tell...
Featuring the first lunar rover in 40 years, Chang'e-3 is seen as an important milestone on China's quest to send a...
Data collected by satellites and floating probes have chronicled a 2-decade rise in the temperature and thickness of a...
Cholesterol, the artery-clogging molecule that contributes to cardiovascular disease, has another nasty trick up its...
- 27 November 2013 12:59 pm , Vol. 342 , #6162
- About Us
ScienceShot: Gregarious Galaxy Groups
29 June 2012 11:30 am
Although the big bang happened long ago, it's still with us because photons from the universe's hot birth pervade space and constitute the cosmic microwave background (shown). Now these ancient photons have revealed the motions of groups and clusters of galaxies born long after the big bang. As the photons zip through hot gas in galaxy groups and clusters, the gas boosts the photons' energy and shortens their wavelength, producing the so-called Sunyaev-Zel'dovich effect, named for two Russians who predicted it before astronomers observed it. But Rashid Sunyaev and Yakov Zel'dovich also predicted that the motions of galaxy groups should affect the photons, something no one ever saw. Now, in the 20 July issue of Physical Review Letters, astronomers will report that they have summed up weak signals from thousands of galaxies and detected the so-called kinematic Sunyaev-Zel'dovich effect, finding to no one's surprise that galaxy groups tend to move toward one another under the influence of their gravity. Future observations could be more revelatory: They may help pin down the nature of the mysterious force that is accelerating the universe's expansion.
See more ScienceShots.