Gumbsch and Gao also found that the supersonic speeds only occur when the stress is applied at a single point. At very low strains, the deformations travel subsonically. At intermediate strains, however, they start supersonically but quickly drop below the sound barrier. But if higher strains are applied, stable supersonic deformation occurs, causing a ‘shock […]
Once the balance between ‘fundamentalists’ and noise traders is breached the market becomes more volatile and creates boom or bust cycles. For example, Amazon.com is now worth over $30 billion, 30 times its predicted revenue this year, despite never making a profit. Lux and Marchesi suggests that the increasing numbers of ‘optimistic’ noise traders investing […]
At the DOE, the budget for basic energy science is set to rise by 11%, with two-thirds of this going to meet construction costs for the Spallation Neutron Source being built at Oak Ridge. Fusion research remains static at $222 m. The $13.6 bn requested for NASA represents a fall of 0.6% compared with this […]
Normal metals have an equal number of electrons with spin “up” and spin “down”. However, when there are more spins pointing up than down, or vice versa, the metal becomes a ferromagnet. Furthermore, the unpaired electrons responsible for the magnetism are pinned by the metal lattice and cannot move. This is what happens in iron. […]
The history of science is littered with famous scientists who pushed the ‘wrong idea’, Perl told PhysicsWeb. And research organisations do not have a good track record of controlling the direction of scientific discoveries. He points out that all efforts to produce energy from controlled nuclear fusion have failed, despite the massive investment in fusion […]
On page 38 of this provocative book, Thomas Gold describes how he began “nosing around in the field of petroleum geology” only after establishing himself as an esteemed astronomer and physicist, and having been elected as a member of several prestigious learned societies. He would not recommend a scientist of lesser standing, “however brilliant”, to […]
When it comes to employing new graduates, scientific institutions are increasingly keen to take on people who have practical scientific experience as well as the academic understanding that a physics degree provides. One way in which undergraduate students can gain this vital experience – and hence improve their job prospects – is by doing work […]
Jaakkola observed two-dimensional Bose-Einstein condensation (2D BEC) in a gas of specially prepared hydrogen atoms adsorbed on the surface of liquid helium. In Bose-Einstein condensation all the particles in a system collapse into a single quantum state that has many unusual and novel properties. Atomic hydrogen was once considered the epitome of a quantum gas, […]
Colloids are also immensely important in a range of industries. Although the products themselves are low-tech – paint, mayonnaise, toothpaste and ice cream, for instance – the physics underpinning these industries is extremely complex and challenging. In the early 1990s several multinational companies with R&D centres in the UK realized that they simply did not […]
Read article: Quantum solitons
Two of the most remarkable properties of light – squeezing and solitons – are being combined in a new generation of experiments that could revolutionize optics and communications
