'Twisted light' data-boosting idea sparks heated debate. 7 November 2012Last updated at 19:05 ET By Jason Palmer Science and technology reporter, BBC News The "twist" of the waves has been put forward as a way to carry vast amounts of data An idea to vastly increase the carrying capacity of radio and light waves has been called into question.
The "twisted light" approach relies on what is called light's orbital angular momentum, which has been put forth as an unexploited means to carry data. Now a number of researchers, including some formally commenting in New Journal of Physics, say the idea is misguided. Responding in the same journal, the approach's proponents insist the idea can in time massively boost data rates. That promise is an enticing one for telecommunications firms that are running out of "space" in the electromagnetic spectrum, which is increasingly crowded with allocations for communications, broadcast media and data transmission. So others are weighing in on what could be a high-stakes debate. Wiggle room “Start Quote. Popular physics theory running out of hiding places. 12 November 2012Last updated at 08:30 ET By Pallab Ghosh Science correspondent, BBC News Supersymmetry predicts heavy versions of all the particles we know about - "super particles" Researchers at the Large Hadron Collider have detected one of the rarest particle decays seen in nature.
The finding deals a significant blow to the theory of physics known as supersymmetry. Many researchers had hoped the LHC would have confirmed this by now. Supersymmetry, or Susy, has gained popularity as a way to explain some of the inconsistencies in the traditional theory of subatomic physics known as the Standard Model. The new observation, reported at the Hadron Collider Physics conference in Kyoto and outlined in an as-yet unpublished paper, is not consistent with many of the most likely models of Susy. Prof Chris Parkes, who is the spokesperson for the UK participation in the LHCb experiment, told BBC News: "Supersymmetry may not be dead but these latest results have certainly put it into hospital. " Shortest laser pulse lasts just 67 attoseconds.
6 September 2012Last updated at 05:16 ET The quest for the shortest pulse has been ongoing since the laser's invention Researchers in the US have produced the shortest-ever laser pulses: just 67 billionths of a billionth of a second. The feat surpasses the prior record of 80 attoseconds, set in 2008. Like a camera with an ever-shorter flash, these 67-attosecond pulses will allow researchers to examine the very fastest natural processes. The team behind the pulses, reporting in Optics Express, have also developed a novel detector to capture them - like a camera with a shutter speed to match. The quest for the shortest laser pulse has been underway since the laser's first demonstration in 1960; the very first laser created pulses of about a thousandth of a second.
In recent years the field of "femtosecond" lasers - producing pulses lasting just millionths of a billionths of a second - have become widespread research tools. 'Twisted light' carries 2.5 terabits of data per second. 25 June 2012Last updated at 03:55 ET The "twist" of the waves within a light beam is a means to carry potentially vast amounts of data Researchers have clocked light beams made of "twisted" waves carrying 2.5 terabits of data - the capacity of more than 66 DVDs - per second. The technique relies on manipulating what is known as the orbital angular momentum of the waves.
Recent work suggests that the trick could vastly boost the data-carrying capacity in wi-fi and optical fibres. The striking demonstration of the approach, reported in Nature Photonics, is likely to lead to even higher rates. Angular momentum is a slippery concept when applied to light, but an analogy closer to home is the Earth itself. Our planet has "spin angular momentum" because it spins on its axis, and "orbital angular momentum" because it is also revolving around the Sun. In many data-carrying applications involving light, more data is packed on to light waves by encoding data streams on different colours of light. Thermal conduction. Heat conduction (or thermal conduction) is the transfer of internal energy by microscopic diffusion and collisions of particles or quasi-particles within a body due to a temperature gradient.
The microscopically diffusing and colliding objects include molecules, electrons, atoms, and phonons. They transfer disorganized microscopic kinetic and potential energy, which are jointly known as internal energy. Conduction can only take place within an object or material, or between two objects that are in direct or indirect contact with each other. Conduction takes place in all forms of ponderable matter, such as solids, liquids, gases and plasmas. Whether by conduction or by thermal radiation, heat spontaneously flows from a hotter to a colder body. In conduction, the heat flow is within and through the body itself.
In the engineering sciences, heat transfer includes the processes of thermal radiation, convection, and sometimes mass transfer. Overview[edit] Steady-state conduction[edit] . Where.