A conducting fluid needs to have a small ‘seed’ magnetic field before it can generate a self- sustaining field. The seed field induces electric currents in the fluid that in turn create a more powerful, and stable, magnetic field. This creation of the field relies on a positive feedback mechanism. However, the process only works […]
The quantum dot device consists of a transistor made of different layers of gallium arsenide and aluminium gallium arsenide. One of the layers consists entirely of quantum dots just nanometers across. The quantum dots are extremely sensitive to photons. A photon hitting the detector liberates an electron trapped in the one of the dots. A […]
The 32-minute film can be downloaded from Sightsound.com. Viewers are charged $3.95 to view it for up to five days, with a higher charge for permanent downloads. The film’s makers, Metafilmics, are hailing The Quantum Project as “every bit as groundbreaking as The Jazz Singer“, the first film to include speech. “We feel this is […]
Read article: ‘The Quantum Project’ hits the Web
Polymer films are used in to make many mass-produced products, such as compact discs. It has been known for some time that the flow rate of liquid polymers can become irregular during the manufacturing process, despite the slow fluid speeds involved. This was surprising because these slow speeds should reduce the effects of inertia, and […]
On Earth, convection or thermal diffusion dominates heat transfer. But these effects are extremely weak in zero gravity, and adiabatic compression can dominate. To observe local overheating and adiabatic compression, Régis Wunenburger from the University of Bordeaux and colleagues placed a small cylinder containing sulfur hexafluoride (SF6) in both its liquid and gas forms on […]
Physics-based techniques play a crucial role in helping archaeologists to unravel the history of our ancestors' lives and reveal previously undiscovered sites without the need to excavate
Read article: Physics and archaeology
The phrase "needle in a haystack" is often used to describe CERN
Read article: CERN prepares for the LHC and beyond
Measurement is at the heart of physics. As physical quantities have been measured with greater and greater accuracy, our knowledge of the world has improved. This applies equally to measurements on the subatomic and intergalactic scales, although the relative error bars are very different. The Planck constant is known to an accuracy of one part […]
When Victor Hess discovered cosmic radiation almost 90 years ago, he did so in manned balloon flights that reached altitudes of up to 5 km in the Earth’s atmosphere. This was only a few years after the Wright brothers’ first flight and neither they nor Hess are likely to have thought that, by the year […]
Read article: Cosmic rays: an in-flight hazard?
The New York conference is intended to specify a timetable for all the main nuclear powers – China, France, Russia, the UK and the US – to abandon their nuclear weapon stockpiles. Delegates will also discuss ways to curb the production of weapons-grade fissile material and promote nuclear non-proliferation among the other states. But many […]
