Photons are traditionally detected by converting their energy into an electric signal, which destroys the photon in the process. An additional problem in quantum measurements is that if one variable – say the position – is measured accurately, then the consequent uncertainty in another, incompatible variable – the momentum in this example – will mean […]
‘t Hooft has made several crucial contributions to the Standard Model of particle physics. In 1967 Salam and Weinberg showed how to unify the weak and electromagnetic interactions – two of the four fundamental forces of nature – into a single electroweak force. In 1971 ‘t Hooft showed that the electroweak force was renormalizable – […]
Until the Dubna experiments all artificial superheavy nuclei had half-lives that were measured in milliseconds. However, the most stable nuclei on the island of stability are predicted to have half-lives of years. The first isotope of element 114 to be discovered – the one with 175 neutrons – has a half-life of 30 seconds, while […]
“Most people in the UK receive their science education through science fiction so it makes sense to study the link between science fiction and science fact,” says Brake. The three year degree course will be split into thirty modules, over half of which will be based on astronomy and space science. There will be seven […]
Scheuer and Orenstein used so-called vertical cavity surface-emitting lasers. In these devices the light is emitted from the top of the active region of the laser, rather than from the edge as in conventional semiconductor lasers. This gives a two-dimensional output in which the patterns can form, rather than the one-dimensional output from conventional devices. […]
Kirkpatrick and co-workers found that the computer algorithms used to solve NP-complete problems can undergo sudden phase transitions as the various criteria used to search for a solution are varied. The solutions get harder to find at the onset of the phase transition – as the search ‘freezes’ – and then easier again once the […]
String theory dates back some 30 years, but it was the “first string revolution” of 1984 that intensified interest in this, the most promising candidate for a “theory of everything”. In this book Brian Greene declares that his central concern is “to explain the workings of the universe according to string theory, with a primary […]
Read article: String theory: simple yet elegant
Wagner, who is 58, studied physics at the Technical University of Munich and the universities of Göttingen and Heidelberg. After spells as a research associate at Heidelberg and the Lawrence Berkeley Laboratory in California, Wagner became a full professor of experimental physics at Heidelberg in 1984. He accepted a chair at the University of Hamburg […]
Neutrinos come in three flavours – electron, muon and tau neutrinos. According to the Standard Model of particle physics they have zero mass and only interact weakly with matter, which makes them very difficult to detect. However, muon neutrinos can change or “oscillate” into electron or tau neutrinos, and so on. Last year the Super-Kamiokande […]
