Friday, 23. October 2009, 07:01:59
computers, nanotechnology, magnetism, Physics
Scientists have generated a magnetic version of electricity, which they have called magnetricity.
The discovery marks an important advance in theoretical physics. The existence of magnetic “charges” has been predicted for nearly 70 years but has never been observed in practice.
The study was led by Professor Steve Bramwell, of the London Centre for Nanotechnology. He said: “It is not often in the field of physics you get the chance to ask, ‘How do you measure something?’, and then go on to prove a theory unequivocally. This is a very important step to establish that magnetic charge can flow like electric charge.”
While electrical current is carried by electrons, magnetricity is based on atomic-sized “north” and “south” charges that flow through materials when placed in a magnetic field.
It is unlikely to become an immediate replacement for electricity because the crystals have to be cooled to below minus 272.15C — just above absolute zero — to be conducting. However, Professor Bramwell said that the discovery could have important applications in the emerging field of nanocomputing.
Source:
http://www.timesonline.co.uk/tol/news/science/physics/article6875326.ece
Tuesday, 29. September 2009, 08:34:13
atomic structure, quantum mechanics, Physics, imaging
For the first time, physicists have photographed the structure of an atom down to its electrons.
The pictures, soon to be published in the journal Physical Review B, show the detailed images of a single carbon atom's electron cloud, taken by Ukrainian researchers at the Kharkov Institute for Physics and Technology in Kharkov, Ukraine.
This is the first time scientists have been able to see an atom's internal structure directly. Since the early 1980s, researchers have been able to map out a material's atomic structure in a mathematical sense, using imaging techniques.
Quantum mechanics states that an electron doesn't exist as a single point, but spreads around the nucleus in a cloud known as an orbital. The soft blue spheres and split clouds seen in the images show two arrangements of the electrons in their orbitals in a carbon atom. The structures verify illustrations seen in thousands of chemistry books because they match established quantum mechanical predictions.
Source:
http://insidescience.org/research/first_detailed_photos_of_atoms
Monday, 28. September 2009, 14:42:57
quantum motor, atoms, Physics
The smallest electric motor could be built from just two ultracold atoms moving in a ring by lasers, according to researchers at University of Augsburg, Germany.
In their latest paper, Alexey Ponomarev, Sergey Denisov, and Peter Hänggi detail the working principles of a theoretical idea for the smallest possible quantum machine and demonstrate that it is able to perform useful work.
The motor consists of one neutral (the starter) atom and one charged (the carrier) atom trapped in a ring-shaped optical lattice, or “bracelet”. Once a magnetic field is applied, the charged atom feels the magnetic flux and moves–but yields no net motion. When placed in the same well of the lattice, like two eggs in the same compartment of a carton, the neutral atom provides a kick to the carrier atom. This kick causes the carrier atom to jump from one site in the lattice to the next, resulting in net movement around the ring.
Source:
http://blogs.zdnet.com/emergingtech/?p=1779
Tuesday, 11. August 2009, 08:03:28
transparent, matter, material, Physics
Oxford scientists claim to have created a transparent form of aluminum by bombarding the metal with the world’s most powerful soft X-ray laser. The substance is nearly transparent to extreme ultraviolet radiation and is the latest addition to a growing list of exotic states of matter.
Crossing over from science fiction to fact, ‘transparent aluminum’ was an idea featured in the movie Star Trek IV. The creation of the real material, however, has implications for areas as diverse as planetary science, astrophysics, and nuclear fusion.
To create the exotic matter, an international team of researchers led by Oxford University scientists used a short pulse from the FLASH laser to ‘knock out’ a core electron from every aluminum atom in a sample without disrupting the metal’s crystalline structure. They report that this turned the aluminum nearly invisible to extreme ultraviolet radiation.
Source:
http://blogs.zdnet.com/emergingtech/?p=1684
Friday, 24. July 2009, 16:58:00
quantum, light, teleportation, Physics
Usually when physicists talk about quantum teleportation, they're referring to the transfer of quantum states from one particle to another without a physical link. Now, physicists have investigated a slightly different form of teleportation, in which they teleport a quantum field, or an entire beam of light, from one location to another. This kind of "strong" teleportation is required for some quantum information applications, and could lead to the teleportation of quantum images.
They have proposed a scheme for teleporting a beam of light, including its fluctuations over time. They hope to show that it’s possible that a physical object (e.g. a quantum field) in one location could emerge at another location in the same quantum state, so that any conceivable measurement would yield the same result in both locations. In contrast, previous teleportation schemes do not seriously consider reproducing certain elements, such as temporal fluctuations.
Source:
http://www.physorg.com/news166779852.html
Tuesday, 6. May 2008, 10:20:48
particles, sub-atomic, Higgs boson, Physics
Get physicists and cosmologists talking about their work and they will tell you that there are elegant theories and messy ones. Almost all of them believe the universe conforms to an elegant one. A central goal of today's physics, in fact, is to show that at its very beginning, the universe was ordered and unified. But this unity didn't last for long. Just instants after the Big Bang, as the explosion cooled and its contents scattered, the cosmos' forces and matter differentiated. The universe fell from a state of perfect grace into its current complexity, in a cosmic parallel to Adam and Eve.
Many great minds — Democritus, Isaac Newton, James Clerk Maxwell, Albert Einstein — took giant steps toward bringing the universe's lost unity out of hiding. In 1964, Peter Higgs, a shy scientist in Edinburgh, added his name to that list by coming up with an ingenious theory that gave scientists the tools to explain how two classes of particles, which now appear to be different, were once one and the same. His theory proposes the existence of a single particle responsible for imparting mass to all things — a speck so precious it has come to be known as the "God particle." The scientific term for it is the Higgs boson, and to find it physicists are counting on the most powerful particle accelerator ever constructed: the Large Hadron Collider (LHC) at the CERN laboratory in Geneva, a 17-mile underground circuit that took 25 years to plan and $6 billion to build.
Source:
http://www.time.com/time/health/article/0,8599,1729139,00.html
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