The researchers from The School of Physics and Astronomy, led by Professor Andre Geim, have found that the world’s thinnest material absorbs a well-defined fraction of visible light, which allows the direct determination of the fine structure constant.
Working with Portuguese theorists from The University of Minho in Portugal, Geim and colleagues report their findings online in the latest edition of Science Express. The paper will be published in the journal Science in the coming weeks.
The universe and life on this planet are intimately controlled by several exact numbers; so-called fundamental or universal constants such as the speed of light and the electric charge of an electron.
Among them, the fine structure constant is arguably most mysterious. It defines the interaction between very fast moving electrical charges and light – or electromagnetic waves – and its exact value is close to 1/137.
Prof Geim, who in 2004 discovered graphene with Dr Kostya Novoselov, a one-atom-thick gauze of carbon atoms resembling chicken wire, says: “Change this fine tuned number by only a few percent and the life would not be here because nuclear reactions in which carbon is generated from lighter elements in burning stars would be forbidden. No carbon means no life.”
Geim now working together with PhD students Rahul Nair and Peter Blake have for the first time produced large suspended membranes of graphene so that one can easily see light passing through this thinnest of all materials.
The researchers have found the carbon monolayer is not crystal-clear but notably opaque, absorbing a rather large 2.3 percent of visible light. The experiments supported by theory show this number divided by Pi gives you the exact value of the fine structures constant.
The fundamental reason for this is that electrons in graphene behave as if they have completely lost their mass, as shown in the previous work of the Manchester group and repeated by many researchers worldwide.
The accuracy of the optical determination of the constant so far is relatively low, by metrological standards.
But researchers say the simplicity of the Manchester experiment is “truly amazing” as measurements of fundamental constants normally require sophisticated facilities and special conditions.
With large membranes in hand, Prof Geim says it requires barely anything more sophisticated then a camera to measure visual transparency of graphene.
“We were absolutely flabbergasted when realized that such a fundamental effect could be measured in such a simple way. One can have a glimpse of the very foundations of our universe just looking through graphene,” said Prof Geim.
“Graphene continues to surprise beyond the wildest imagination of the early days when we found this material.
“It works like a magic wand – whatever property or phenomenon you address with graphene, it brings you back a sheer magic.
“I was rather pessimistic about graphene-based technologies coming out of research labs any time soon. I have to admit I was wrong. They are coming sooner rather than later.”
Alex Waddington | EurekAlert!
The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
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....
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...
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...
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....
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
23.11.2017 | Information Technology
23.11.2017 | Physics and Astronomy
23.11.2017 | Life Sciences