Detection of a cosmic effect

The first observation of a cosmic effect theorized 40 years ago could provide astronomers with a more precise tool for understanding the forces behind the universe's formation and growth, including the enigmatic phenomena of dark energy and dark matter.

Proposed in 1972 by Russian physicists Rashid Sunyaev and Yakov Zel'dovich, the kSZ effect results when the hot gas in galaxy clusters distorts the cosmic microwave background radiation — which is the glow of the heat left over from the Big Bang — that fills our universe. Radiation passing through a galaxy cluster moving toward Earth appears hotter by a few millionths of a degree, while radiation passing through a cluster moving away appears slightly cooler

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Nuclear Clock Accurate Over Billions of Years

A clock accurate to within a tenth of a second over 14 billion years – the age of the universe – is the goal of research being reported this week by scientists from three different institutions. To be published in the journal Physical Review Letters, the research provides the blueprint for a nuclear clock that would get its extreme accuracy from the nucleus of a single thorium ion.

This RF ion trap holds individual thorium atoms while they are laser-cooled to near absolute zero temperature. (Click image for high-resolution version. Credit: Corey Campbell)

 

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