
John Bell and the most profound discovery of science
Andrew Whitaker on how John Bell investigated quantum theory in the greatest depth and established what it can tell us about the fundamental nature of the physical world
Thank you for registering with Physics World
If you'd like to change your details at any time, please visit My account
Andrew Whitaker on how John Bell investigated quantum theory in the greatest depth and established what it can tell us about the fundamental nature of the physical world
Everyday experience tells us that it is impossible to travel backwards in time, no matter what science-fiction writers and movie directors tell us. However, this seemingly natural impossibility is actually one of the greatest mysteries in physics. Currently most physicists associate the irreversibility of time with the production of entropy in the warm macroscopic […]
Once upon a time the news that the budget for particle physics and astronomy in the UK was going to keep pace with inflation for three years (see Physics fails to keep pace in the UK) would have been greeted with jubilation. After declining in real terms for the past 20 years, a period of […]
Richter, 67, will remain on the faculty at Stanford University and will be the next president of the International Union of Pure and Applied Physics. Richter’s main achievements at SLAC have been the construction of the two-mile Stanford Linear Collider (SLC), the world’s first linear collider, and the Stanford B-factory. Work on the SLC began […]
Experimentalists at CERN will use a cloud chamber to mimic the Earth’s atmosphere in order to try and determine whether cloud formation is influenced by solar activity. According to the Danish theory, charged particles from the Sun deflect galactic cosmic rays (streams of high-energy particles from outer space) that would otherwise have ionized the Earth’s […]
The team looked in particular for ‘lag time’ effects in the data. For example, the eruption of Mt Pinatubo in the Philippines in 1991 lowered the global temperature by 0.3 C in the following year as fine aerosols of volcanic ash and sulphuric acid caused a cooling effect. However, the team believes that volcanic eruptions […]
Semiconductor lasers are usually monocromatic because the electrons stored in energy bands do not emit any photons unless they move out of the semiconductor’s conduction band. Federico Capasso and colleagues have created the multi-wavlength laser by modifying the conduction band by building 25 different sandwich layers of material into the device. Each sandwich consists of […]
The 1995 image was taken in a small patch near the Big Dipper constellation, which astronomers previously thought was completely blank. This new image taken by the Space Telescope Science Institute and NASA’s Goddard Space Flight Center last month, was of the constellation Tucana, near the south celestial pole. “We have eagerly awaited this new […]
The 24 ton Zarya (meaning “daybreak”) module is based on the long experience the Russian Space Agency has had with the Mir space station. Unlike the US space station Skylab, which was until Mir the largest object in orbit, the module can stay in space for 430 days without re-fuelling. The Russian space company Khrunichev […]
Fibre-optic cables usually consist of an inner core of highly refractive glass sheathed inside glass with a lower refractive index. Light travels along the inner core fibre by total internal reflection. However, despite their popularity, standard optical fibers have a number of limitations. They are difficult to manufacture, light can leak from the inner core, […]