Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dark Energy Alternatives to Einstein Are Running Out of Room

10.01.2013
Research by University of Arizona astronomy professor Rodger Thompson finds that a popular alternative to Albert Einstein’s theory for the acceleration of the expansion of the universe does not fit newly obtained data on a fundamental constant, the proton to electron mass ratio.
Thompson's findings, reported Jan. 9 at the American Astronomical Society meeting in Long Beach, Calif., impact our understanding of the universe and point to a new direction for the further study of its accelerating expansion.

To explain the acceleration of the expansion of the universe, astrophysicists have invoked dark energy – a hypothetical form of energy that permeates all of space. A popular theory of dark energy, however, does not fit new results on the value of the proton mass divided by the electron mass in the early universe.

Thompson computed the predicted change in the ratio by the dark energy theory (generally referred to as rolling scalar fields) and found it did not fit the new data.

UA alumnus Brian Schmidt, along with Saul Perlmutter and Adam Reiss, won the 2011 Nobel Prize in Physics for showing that the expansion of the universe is accelerating rather than slowing down as previously thought.

The acceleration can be explained by reinstating the "cosmological constant" into Einstein's theory of General Relativity. Einstein originally introduced the term to make the universe stand still. When it was later found that the universe was expanding, Einstein called the cosmological constant "his biggest blunder."

The constant was reinstated with a different value that produces the observed acceleration of the universe’s expansion. Physicists trying to calculate the value from known physics, however, get a number more than 10 to the power of 60 (one followed by 60 zeros) too large – a truly astronomical number.

That's when physicists turned to new theories of dark energy to explain the acceleration.

In his research, Thompson put the most popular of those theories to the test, targeting the value of a fundamental constant (not to be confused with the cosmological constant), the mass of the proton divided by the mass of the electron. A fundamental constant is a pure number with no units such as mass or length. The values of the fundamental constants determine the laws of physics. Change the number, and the laws of physics change. Change the fundamental constants by a large amount, and the universe becomes very different from what we observe.

The new physics model of dark energy that Thompson tested predicts that the fundamental constants will change by a small amount. Thompson identified a method of measuring the proton to electron mass ratio in the early universe several years ago, but it is only recently that astronomical instruments became powerful enough to measure the effect. More recently, he determined the exact amount of change that many of the new theories predict.

Last month, a group of European astronomers, using a massive radio telescope in Germany, made the most accurate measurement of the proton-to-electron mass ratio ever accomplished and found that there has been no change in the ratio to one part in 10 million at a time when the universe was about half its current age, around 7 billion years ago.

When Thompson put this new measurement into his calculations, he found that it excluded almost all of the dark energy models using the commonly expected values or parameters. If the parameter space or range of values is equated to a football field, then almost the whole field is out of bounds except for a single 2-inch by 2-inch patch at one corner of the field. In fact, most of the allowed values are not even on the field.

"In effect, the dark energy theories have been playing on the wrong field," Thompson said. "The 2-inch square does contain the area that corresponds to no change in the fundamental constants, and that is exactly where Einstein stands."

Thompson expects that physicists and astronomers studying cosmology will adapt to the new field of play, but for now, "Einstein is in the catbird seat, waiting for everyone else to catch up."

Jennifer Fitzenberger | University of Arizona
Further information:
http://www.arizona.edu

More articles from Physics and Astronomy:

nachricht Scientific achievements during the operation of Lomonosov satellite
18.12.2017 | Lomonosov Moscow State University

nachricht Quantum memory with record-breaking capacity based on laser-cooled atoms
18.12.2017 | Faculty of Physics University of Warsaw

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: Error-free into the Quantum Computer Age

A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors.

In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means...

Im Focus: Search for planets with Carmenes successful

German and Spanish researchers plan, build and use modern spectrograph

Since 2016, German and Spanish researchers, among them scientists from the University of Göttingen, have been hunting for exoplanets with the “Carmenes”...

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

The body's street sweepers

18.12.2017 | Life Sciences

Fast flowing heat in layered material heterostructures

18.12.2017 | Materials Sciences

Life on the edge prepares plants for climate change

18.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>