Refining a cosmic clock

Physicists will soon have a better measure of the age of our galaxy, thanks to experiments described in a trio of papers appearing in the journal Physical Review C.

The papers report on experiments at the CERN neutron time-of-flight (n_TOF) facility and the Karlsruhe Van de Graaff accelerator that clarify the processes that affect the abundance of the element osmium-187. The element is created when rhenium-187 decays. Because rhenium-187 was produced in the first stellar explosions after the birth of the galaxy, measuring the amounts of rhenium-187 and osmium-187 we observe today can provide an estimate of the galaxy's age. In effect, the elements act as a cosmic clock that started ticking when the galaxy was born.

Unfortunately, there are various processes that can affect the amounts of osmium we measure. Uncertainties in our understanding of those processes have limited the accuracy of the cosmic clock to more than a billion years. The CERN and Karlsruhe experiments involve firing pulses of neutrons into an osmium target to determine how frequently the element is likely to capture neutrons and convert to another material. The data the researchers collected has reduced uncertainties in the rhenium-osmium cosmic clock to less than a billion years, allowing a better estimate of our roughly 14 billion year old galaxy.

For further information, see a synopsis of papers on the APS Physics website (physics.aps.org).

About APS Physics:

APS Physics (http://physics.aps.org) publishes expert written commentaries and highlights of papers appearing in the journals of the American Physical Society.

Media Contact

James Riordon EurekAlert!

More Information:

http://www.aps.org

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors