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From EurekAlert (Australian National University):
Physicists have found a radical new way [to] confine electromagnetic energy without it leaking away, akin to throwing a pebble into a pond with no splash. The theory could have broad ranging applications from explaining dark matter to combating energy losses in future technologies. However, it appears to contradict a fundamental tenet of electrodynamics, that accelerated charges create electromagnetic radiation, said lead researcher Dr Andrey Miroshnichenko from The Australian National University (ANU).
"This problem has puzzled many people. It took us a year to get this concept clear in our heads," said Dr Miroshnichenko, from the ANU Research School of Physics and Engineering. The fundamental new theory could be used in quantum computers, lead to new laser technology and may even hold the key to understanding how matter itself hangs together.
"Ever since the beginning of quantum mechanics people have been looking for a configuration which could explain the stability of atoms and why orbiting electrons do not radiate," Dr Miroshnichenko said. The absence of radiation is the result of the current being divided between two different components, a conventional electric dipole and a toroidal dipole (associated with poloidal current configuration), which produce identical fields at a distance. If these two configurations are out of phase then the radiation will be cancelled out, even though the electromagnetic fields are non-zero in the area close to the currents.
Dr Miroshnichenko, in collaboration with colleagues from Germany and Singapore, successfully tested his new theory with a single silicon nanodiscs between 160 and 310 nanometres in diameter and 50 nanometres high, which he was able to make effectively invisible by cancelling the disc's scattering of visible light.
Nonradiating anapole modes in dielectric nanoparticles and arXiv PDF.
(Score: 4, Insightful) by stormwyrm on Monday August 31 2015, @12:36AM
I always thought that atoms didn't radiate because quantum theory had it that there were only discrete quantum states at specific energy levels that the electrons could occupy, so they could only gain or lose energy in steps, hence the discrete emission spectra of atoms when they make those quantum state transitions. For an atom to radiate its electrons would need to make such a state transition, but for most ordinary atoms the electrons are in the ground state, with no lower energy state where they could go, and hence no radiation. I suppose they must be talking about a new theory then rather than attempting to second-guess Schrödinger and Feynman.
By the way, the "radical way confine" typo seems to be in the original article.
Numquam ponenda est pluralitas sine necessitate.
(Score: 2) by Non Sequor on Monday August 31 2015, @02:21AM
I'm not sure if there's really a difference between having a discrete state space or having a larger state space where most of the states have a negligible presence due to destructive interference.
Write your congressman. Tell him he sucks.
(Score: 2) by eof on Monday August 31 2015, @02:43PM
When the scientist says "Ever since the beginning of quantum mechanics people have been looking for a configuration which could explain the stability of atoms and why orbiting electrons do not radiate," I think they are putting things in context. According to classical electrodynamics, an atom would be unstable because its electrons accelerate as they move in their classical orbits. An accelerating electron radiates and loses energy. This would result in the electron orbit decaying until it was stuck on the nucleus.
Bohr hypothesized that there were only discrete states to take care of the observed existence of atoms. This and his other hypotheses were moderately successful. Eventually physicists came to a more formal theory of quantum mechanics in which the idea of energy levels came about "naturally." Schrödinger was among those who developed the more formal theory; Feynman came along later.
I haven't read the paper, but I doubt the authors claim to overthrow quantum theory. Given that the calculations appear classical, it would be interesting to revisit the classical atom to see if its decay can be avoided.