Strength is weakness on the Internet
In a ‘scale-free’ network of many interconnected nodes, like the Internet, most of the nodes are connected to a relatively small number of other nodes. Only a very small minority have a la...
Tau neutrino identified at last
The DONUT team fired an intense beam of neutrinos, which they expected to contain tau neutrinos, at a target consisting of iron plates with layers of emulsion sandwiched between them. One in a million...
Sir Mark Oliphant dies
Oliphant was born in Adelaide in 1901 and attended the local university before going to Cambridge University in 1927, where he worked on nuclear physics experiments with Ernest Rutherford. In 1937 he ...
Microscopy: two lasers are better than one
Stefan Hell and co-workers at Gottingen have adapted a technique known as fluorescence microscopy. In this form of microscopy the specimen is irradiated at a wavelength which excites either natural or...
Laser smashes light-speed record
Special relativity prevents any object with mass travelling at the speed of light, and the principle of causality – the notion that the cause comes before the effect – is used to rule out ...
Superconducting gains
The device has three electrodes: a niobium injector electrode; a common electrode that consists of a layer of niobium and a layer of aluminium; and a niobium detector electrode. The electrodes are sep...
Nuclei show their soft side
Helium-6 is a typical neutron-skin nucleus, with two of the neutrons forming a “skin” around the alpha-particle core. Different types of dynamics are possible in such nuclei. In the soft d...
Laser control of X-ray output
In harmonic generation a short pulse of intense radiation is focussed into a gas of atoms. The laser-atom interactions are highly nonlinear, and a number of the input photons effectively combine to ge...
Schrodinger’s cat comes into view
In his original thought experiment, Schrodinger imagined that a cat is locked in a box, along with a radioactive atom that is connected to a vial containing a deadly poison. If the atom decays, it cau...
Theory, experiment and fine structure
Spectroscopy – the measurement of the properties of light emitted or absorbed by matter – is one of our most powerful tools to study nature. When a prism is used to separate the light from...
