In a photonic crystal the periodic variation of the dielectric constant results in a range of ‘forbidden’ frequencies called a photonic bandgap (PBG). Electromagnetic waves with a ‘forbidden’ frequency cannot propagate through the crystal. This phenomenon can be exploited to create a waveguide. Adding a strip of linear defects to the PBG material destroys the […]
Read article: ‘Floating planets’ challenge theorists
Many planets have been discovered outside our solar system, but they are usually detected by observing the wobble of the parent star induced by the gravitational pull of the orbiting planet. Zapatero Osorio’s team, however, observed the floating planets directly by optical and infrared imaging. The objects are dim and reddish – the characteristics of […]
Read article: A strange quark plasma
Experiments have recreated the conditions that existed in the early universe before the protons and neutrons that make up the world today had formed
Read article: Countdown to the Nobel prize
The Nobel Foundation celebrates its 100th birthday this year. Peter Rodgers looks at how the winners are selected and some of the discoveries that might be recognized this year
Read article: New era for European Universities
Universities across Europe are scrapping their traditional degrees in favour of British-style qualifications. But some physicists on the continent believe this will lead to a drop in standards
Read article: Superconductivity leaves the lab
Superconducting magnets are a common tool in many physics and chemistry laboratories, and are used in a host of research applications, including solid-state physics, nuclear-magnetic-resonance chemistry and particle physics. Outside the research lab, the only truly widespread use of superconducting magnets is in magnetic resonance imaging (MRI) in medicine. However, applications of superconducting magnets are […]
Read article: Beyond understanding 2
Over the past 15 years there have been significant increases in the coverage of science in the mass media and the number of hands-on science centres in the UK, two developments that would be expected to foster better “public understanding of science”. But as noted in Who’s Misunderstanding Whom? (see links), a new report on […]
Read article: Hawking: the cardboard creation
Julian Barbour reviews the play God and Stephen Hawking by Robin Hawdon
The Hubble constant, which is the rate at which the velocity of a galaxy increases with distance, is one of the most fundamental constants in cosmology. Astronomers can only obtain an accurate value for the constant using ‘standard candles’, which give reliable and accurate measurements of the distance to receding galaxies. One such class of […]
Computer chips are made using a process called optical lithography, in which light traces out patterns on a photosensitive substrate covering the silicon. The problem for chipmakers who want to make ever smaller components is that materials needed for lenses and other optical components are not effective at wavelengths below the ultraviolet. Optical lithography therefore […]
