Sacred constant might be changing
Scientists discover one of the constants of the universe might not be constant
Physical constants are one of the cornerstones of physics – sacred numbers which we know to be fixed – but what if some of these constants are changing? Speaking at the Institute of Physics conference Physics 2005, Dr Michael Murphy of Cambridge University will discuss the "fine structure constant" – one of the critical numbers in the universe which seems to be precisely tuned for life to exist – and suggest that it might not be constant after all.
Dr Murphy has used the largest optical telescope in the world, the Keck telescope on Mauna Kea in Hawaii, to study light from distant quasars. This light has been travelling across the universe for billions of years, and seems to show that the fine structure constant, often known as "alpha", may be varying over time.
The fine structure constant governs the electromagnetic force which holds all atoms and molecules together. Scientists have known for many years that if its value was slightly different, life could not exist. Only the very tiniest changes over time could be tolerated, and most scientists believe that alpha today is the same as it always has been.
The constant also affects the absorption fingerprint of atoms, which can be detected when light shines through gas clouds. Murphy has used quasars as incredibly distant light sources, whose light encounters gas clouds on its way to Earth. The light takes time to reach Earth, so he sees the fingerprints as they were billions of years ago. By comparing these fingerprints with those obtained in experiments on Earth, he concludes that alpha has changed by about one part in two-hundred-thousand during the last 10 billion years.
Other researchers have published results which suggest that alpha does not change. However Dr Murphys work is the most detailed survey ever performed. He says that the internal checks in his method, which other research groups did not use, make this the most reliable measurement to date.
Murphy is careful not to claim that the case is closed, and he says that nobody can really say that alpha varies until another type of experiment has confirmed it. "We are claiming something extraordinary here," says Murphy, "and the evidence, though strong, is not yet extraordinary enough."
Dr Michael Murphy is a Research Associate at the Institute of Astronomy in the University of Cambridge, and a Research Fellow of Darwin College, Cambridge.
David Reid | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Mapping the interaction of a single atom with a single photon may inform design of quantum devices
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...