ScienceDaily (Sep. 9, 2010) — A team of astrophysicists based in Australia and England has uncovered evidence that the laws of physics are different in different parts of the universe.
The report describes how one of the supposed fundamental constants of Nature appears not to be constant after all. Instead, this ‘magic number’ known as the fine-structure constant — ‘alpha’ for short — appears to vary throughout the universe.
“After measuring alpha in around 300 distant galaxies, a consistency emerged: this magic number, which tells us the strength of electromagnetism, is not the same everywhere as it is here on Earth, and seems to vary continuously along a preferred axis through the universe,” Professor John Webb from the University of New South Wales said.
The researchers’ conclusions are based on new measurements taken with the Very Large Telescope (VLT) in Chile, along with their previous measurements from the world’s largest optical telescopes at the Keck Observatory in Hawaii.
Mr Julian King from the University of New South Wales explained how, after combining the two sets of measurements, the new result ‘struck’ them. “The Keck telescopes and the VLT are in different hemispheres — they look in different directions through the universe. Looking to the north with Keck we see, on average, a smaller alpha in distant galaxies, but when looking south with the VLT we see a larger alpha.”
“It varies by only a tiny amount — about one part in 100,000 — over most of the observable universe, but it’s possible that much larger variations could occur beyond our observable horizon,” Mr King said.
Other researchers involved in the research are Professor Victor Flambaum and PhD student Matthew Bainbridge from the University of New South Wales, and Professor Bob Carswell at the University of Cambridge (UK).
ScienceDaily (Apr. 4, 2008) — Researchers at The University of Manchester have used graphene to measure an important and mysterious fundamental constant – and glimpse the foundations of the universe.
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.
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.
Working with Portuguese theorists from The University of Minho in Portugal, Geim and colleagues report their findings online in Science Express. The paper will be published in the journal Science in the coming weeks.
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.
(Matrix note: since that graphene represents a perfect closed system it is predicted that it does not accept intrusion, so, it must not absorble light. This is the reason it is opaque? But, transformed into building block among organic matter it needs a strong substance for performing the bridges linking the atoms. Maybe here light, photons, are necessary: only when graphene is performing molecules. See this from wilipedia: “graphene is a single atomic plane of graphite, which—and this is essential—is sufficiently isolated from its environment to be considered free-standing.”
And see also: As of 2009, graphene appears to be one of the strongest materials ever tested. Measurements have shown that graphene has a breaking strength 200 times greater than steel.)
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.
(Matrix note: well… matter for many thoughts. The scientist’s theory makes sense: for a terrestrial atom changing his natural behavior which composes gases, rocks, water, etc., it needs a strong charge of photons from LUCA. Of course, the proportion between mass and energy of particles should change. Or maybe is the case that the mass inside the atom are acelerated and transformed into energy, which is manipulated by LUCA? See this from wikipedia: It has proven difficult to synthesize even slightly bigger molecules, and they still remain “a dream of many organic and polymer chemists”. Furthermore, ab initio calculations show that a graphene sheet is thermodynamically unstable with respect to other fullerene structures if its size is less than about 20 nm (“graphene is the least stable structure until about 6000 atoms” and becomes the most stable one (as within graphite) only for sizes larger than 24,000 carbon atoms). The flat graphene sheet is also known to be unstable with respect to scrolling, which is its lower energy state.)
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.”
From Wikipedia, the free encyclopedia
is a one-atom-thick planar sheet of sp2
atoms that are densely packed in a honeycomb crystal lattice. It can be visualized as an atomic-scale chicken wire
made of carbon atoms and their bonds. The name comes from graphite
; graphite itself consists of many graphene sheets stacked together.
The carbon-carbon bond length in graphene is about 0.142 nm. Graphene is the basic structural element of some carbon allotropes including graphite, carbon nanotubes and fullerenes. It can also be considered as an infinitely large aromatic molecule, the limiting case of the family of flat polycyclic aromatic hydrocarbons called graphenes.
DescriptionA simple, non-technical definition has been given in a recent review on graphene:
Graphene is a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite.
Previously, graphene was also defined in the chemical literature as follows:
A single carbon layer of the graphitic structure can be considered as the final member of the series naphthalene, anthracene, coronene, etc. and the term graphene should therefore be used to designate the individual carbon layers in graphite intercalation compounds. Use of the term “graphene layer” is also considered for the general terminology of carbons.
In 2004 physicists from University of Manchester and Institute for Microelectronics Technology, Chernogolovka, Russia, found a way to isolate individual graphene planes by using Scotch tape and they also measured electronic properties of the obtained flakes and showed their fantastic quality. In 2005 the same Manchester group together with researchers from the Columbia University (see the History chapter below) demonstrated that quasiparticles in graphene were massless Dirac fermions. These discoveries led to the explosion of interest in graphene.
In 2008 graphene produced by exfoliation was one of the most expensive materials on Earth, with a sample that can be placed at the cross section of a human hair costing more than $1,000 as of April 2008 (about $100,000,000/cm2). Since then, exfoliation procedures were scaled up, and now companies sell graphene by ton. On the other hand, the price of epitaxial graphene on silicon carbide is dominated by the substrate price, which is approximately $100/cm2 as of 2009. Even cheaper graphene has been produced by transfer from nickel by Korean researchers, with wafer sizes up to 30″ reported.
Despite the zero carrier density near the Dirac points, graphene exhibits a minimum conductivity on the order of 4e2 / h. The origin of this minimum conductivity is still unclear. However, rippling of the graphene sheet or ionized impurities in the SiO2 substrate may lead to local puddles of carriers that allow conduction. Several theories suggest that the minimum conductivity should be 4e2 / πh; however, most measurements are of order 4e2 / h or greater and depend on impurity concentration.
(Matrix notes: as organic closed system copy graphene should be not conductor. the low conductivity must be due impurity.)