Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Examination of radiation left from birth of universe could alter theories

03.04.2007
Using relic radiation from the birth of the universe, astrophysicists at the University of Illinois have proposed a new way of measuring the fine-structure constant in the past, and comparing it with today.

By focusing on the absorption of the cosmic microwave background by atoms of neutral hydrogen, the researchers say, they could measure the fine-structure constant during the “dark ages,” the time after the Big Bang before the first stars formed, when the universe consisted mostly of neutral hydrogen and helium.

The fine-structure constant characterizes the strength of the electromagnetic force, which is one of the four fundamental forces in physics. But, the fine-structure constant may not be constant. Recent observations of quasars – starlike objects billions of light-years away – have found a slightly different value for the fine-structure constant.

“If the fine-structure constant does vary over time and space, we could use it as a probe of new physics beyond the standard model and beyond general relativity,” said Benjamin Wandelt, a cosmologist at the Illinois, who developed the proposed measurement technique with graduate student Rishi Khatri.

A varying fine-structure constant also could help explain the mysterious dark energy that pervades the universe, Wandelt said, and help constrain what kind of theory would unite the four fundamental forces into a “theory of everything.” Using light from quasars, astronomers can look for variations in the fine-structure constant from the present up to 5 billion years ago. Using the spectra of neutral hydrogen, astronomers can peer much further back in time.

“There is a void from about 300,000 years after the Big Bang, when radiation that formed the cosmic microwave background was emitted, to about 500 million years later, when the first stars formed,” Wandelt said. “Our measurement technique could probe the fine-structure constant during this period, known as the dark ages.”

When a neutral hydrogen atom absorbs a photon of light from the cosmic microwave background, the electron flips its spin, causing a slight difference in its spectrum.

The telltale fingerprint of this atomic transition at a wavelength of 21 centimeters can serve as a sensitive search for past values of the fine-structure constant, said Wandelt and Khatri, who describe their measurement technique in a paper accepted for publication in the journal Physical Review Letters, and posted on its Web site.

While most radio telescopes are too small to look for variations in the fine-structure constant, there are new instruments in the design or construction phase – including the Long Wavelength Array and the Low Frequency Array – that will provide the first limits when brought on line.

“The measurements would be tricky, but not impossible,” Wandelt said.

James E. Kloeppel | EurekAlert!
Further information:
http://www.uiuc.edu

More articles from Physics and Astronomy:

nachricht Quantum optics allows us to abandon expensive lasers in spectroscopy
22.11.2017 | Lomonosov Moscow State University

nachricht Nano-watch has steady hands
22.11.2017 | University of Vienna

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>