Physics

  The result of my research into F(4) symmetry and my theory of Quantum Space-Time Dynamics. Month's ago I wrote of my interest in researching the exceptional lie group and algebra F(4) in relation to the theory of Quantum Space-Time Dynamics.  I now have my results.  The investigation was pretty standard and not surprising.  Intuition told me that the fields in my theory, which I wrote down years before I really knew about quantum field theory, had this symmetry.  What did surprise me and disturb me was when I considered what the conserved current due to the F(4)…

A University of Utah study is shedding light on an important, unsolved physics problem: the relationship between chaos theory – which is based on 300-year-old Newtonian physics – and the modern theory of quantum mechanics. The study demonstrated a fundamental new property – what appears to be chaotic behavior in a quantum system – in the magnetic "spins" within the nuclei or centers of atoms of frozen xenon, which normally is a gas and has been tested for making medical images of lungs. The new study in Physical Review Letters was led by Brian Saam, an associate professor of physics and…

The pinhole camera, a technique known since ancient times, has inspired a futuristic technology for lensless, three-dimensional imaging. Working at both the Advanced Light Source (ALS) at the U.S. Department of Energy's Lawrence Berkeley National Laboratory, and at FLASH, the free-electron laser in Hamburg, Germany, an international group of scientists has produced two of the brightest, sharpest x-ray holograms of microscopic objects ever made, thousands of times more efficiently than previous x-ray-holographic methods. The x-ray hologram made at ALS beamline 9.0.1 was of Leonardo da Vinci's…

Judging by the astonishing increase in journal papers written by scientists in China, China is finding its place as one of the world’s scientific power houses, says Michael Banks, but he also quantifies this surge in scientific output China and measures whether quality matches quantity in August’s Physics World. Nanoscience, quantum computing and high-temperature superconductivity are three of the cutting-edge areas of physics that have seen particularly large increases. Published journal articles in nanoscience, for example, with at least one co-author based in China, have seen a 10-fold…

A bizarre title, but nothing to do with the fact that I am constitutionally lazy. Rather, it is related to the war I and a colleague are attempting to wage against the way physics is (in the UK at least) treated as a form of applied mathematics. It also has direct application to astrophysics – I know one student who went to study physics at university in 2002, in large part attracted by astronomy, but after a second year including astrophysics was saying "I hate stars." He was quite reasonable at maths, but it is the way that the subject was presented that put him off. What’s wrong with…

Scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley have performed the first scanning tunneling spectroscopy of graphene flakes equipped with a "gate" electrode. The result is the latest in a series of surprising insights into the electronic behavior of this unique, two-dimensional crystal form of carbon: an unexpected gap-like feature in the energy spectrum of electrons tunneling into graphene's single layer of atoms. Michael Crommie, a faculty scientist in Berkeley Lab's Materials Sciences Division…

I first came across the word synchrotron in connection with the Crab Nebula, as well explained here at Hyperphysics. However, the phenomenon is these days very much down-to-earth: last weekend I returned from our last ever session at the Daresbury Synchrotron, which is soon to be shut down (final public use Saturday 1st August 2008). It first came on-line for experiments in 1981: prior to that, intense X-ray and hard UV synchrotron radiation was obtained as a by-product through “parasitic” operation on particle storage rings. Among others, Reading’s own Keith Codling had shown that much…

By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, scientists have determined the mass of the galaxy's supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique. Astronomers have been seeking different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the sun. Until now, methods based on observing the motions of stars or of gas in a disk near such large black holes had been used. "…

Have you ever been puzzled by a statement like this: “Rotating a spin-1/2 particle by 360° does not bring it back to the same quantum state, but to the state with the opposite quantum phase; this is detectable, in principle, with interference experiments. To return the particle to its exact original state, one needs a 720° rotation.” (Wikipedia). Last week I zoomed back to 1820 and introduced Ørsted and his famous experiment, and left you with a promise of going mathematical tomb raiding. Tomb Raider was first released in 1996 for the Sega Saturn, and other platforms followed. The lore…

European researchers are the first to demonstrate functional components that exploit the magnetic properties of electrons to perform logic operations. Compatible with existing microtechnology, the new approach heralds the next era of faster, smaller and more efficient electronics. In the 1960s, Henry Moore observed that it took around 18 months for silicon chip manufacturers to shrink their technology and fit twice as many transistors into the same area of silicon. But Moore's Law is beginning to lose its hold. According to the International Technology Roadmap for Semiconductors (ITRS),…