Featured Research

from universities, journals, and other organizations

Have Constants Of Nature Have Changed Since The Dawn Of The Universe?

Date:
April 29, 2006
Source:
National Institute of Standards and Technology
Summary:
Physicists at JILA have performed the first-ever precision measurements using ultracold molecules, in work that may help solve a long-standing scientific mystery -- whether so-called constants of nature have changed since the dawn of the universe.

Physicists at JILA have performed the first-ever precision measurements using ultracold molecules, in work that may help solve a long-standing scientific mystery--whether so-called constants of nature have changed since the dawn of the universe.

The research, reported in the April 14 issue of Physical Review Letters,* involved measuring two phenomena simultaneously--electron motion, and rotating and vibrating nuclei--in highly reactive molecules containing one oxygen atom and one hydrogen atom. The researchers greatly improved the precision of these microwave frequency measurements by using electric fields to slow down the molecules, providing more time for interaction and analysis. JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.

Compared to the previous record, set more than 30 years ago, the JILA team improved the precision of one frequency measurement 25-fold and another 10-fold. This was achieved by producing pulses of cold molecules at various speeds, hitting each group with a microwave pulse of a selected frequency, and then measuring how many molecules were in particular energy states. The apparatus and approach were similar to those used in the NIST-F1 cesium atomic fountain clock, the nation's primary time standard, raising the possibility of designing a clock that keeps time with molecules, instead of atoms.

The JILA team's ability to make two molecular measurements at once enables scientists to apply mathematical calculations to probe the evolution over time of fundamental natural properties such as the fine structure constant, which is widely used in research to represent the strength of electromagnetic interactions. Another research group at the National Radio Astronomy Observatory plans to make similar frequency measurements soon of the same molecules produced in distant galaxies, which are so far from Earth that they represent a window into ancient history. By comparing precision values for the fine structure constant on Earth and in distant parts of the universe, scientists hope to determine whether this constant has changed over 10 billion years. Because the fine structure constant is used in so many fields of physics, these measurements are a way to test the consistency of existing theories. The JILA measurements could enable any change in the fine structure constant over time to be determined with a precision of one part per million.

The work at JILA is supported by the National Science Foundation, NIST, the Department of Energy, and the Keck Foundation.

*E.R. Hudson, H.J. Lewandowski, B.C. Sawyer, and J.Ye. 2006. Cold molecule spectroscopy for constraining the evolution of the fine structure constant. Physical Review Letters. April 14 (Vol. 96, 143004).


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology. Note: Materials may be edited for content and length.


Cite This Page:

National Institute of Standards and Technology. "Have Constants Of Nature Have Changed Since The Dawn Of The Universe?." ScienceDaily. ScienceDaily, 29 April 2006. <www.sciencedaily.com/releases/2006/04/060429124748.htm>.
National Institute of Standards and Technology. (2006, April 29). Have Constants Of Nature Have Changed Since The Dawn Of The Universe?. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2006/04/060429124748.htm
National Institute of Standards and Technology. "Have Constants Of Nature Have Changed Since The Dawn Of The Universe?." ScienceDaily. www.sciencedaily.com/releases/2006/04/060429124748.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins