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 […]
There are already over 300 million documents on the Internet, and only 34% of them have been catalogued by the most popular search engines such as Hotbot. This has made the topology of the Internet extremely difficult to describe or measure. However, Reka Albert, Hawoong Jeong and Albert-László Barabási of the University of Notre Dame […]
“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. […]
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 […]
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 […]
Read article: String theory: simple yet elegant
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 […]
When astronomers train their telescopes on the heavens, they are not always looking for the most distant objects in the sky. Indeed there is much to be learnt from focusing a telescope closer to home. The amount of variety in the solar system alone is staggering, although recent observations of planets around other stars suggest […]
