Read article: World’s most expensive sundial
The aluminium sundial features rings representing the orbits of Mars and Earth, and red and blue dots showing the position of the two planets at the time of the landing. Once safely installed on Mars, the sundial will relay local Martian time to a Web-site. And in a week in which Germany hosted a conference […]
Upsilon Andromedae is a yellow G-type star similar to the Sun. In 1996 Geoffrey Marcy from San Francisco State University, together with Butler, discovered one planet by observing a ‘wobble’ in the star’s rotational velocity. This planet is about three-quarters the mass of Jupiter and orbits the star every 4.6 days. However, an unusual scattering […]
The three-day workshop was held in Debreccen in Hungary last month and involved physicists from both eastern and western Europe. Delegates were concerned about a number of ‘serious problems’ that physics faces both with its relationship with the general public, and as a discipline. The workshop pointed out, for example, that the public often cites […]
Polycrystalline materials contain lots of tiny crystals oriented randomly in space. Thomas Wessels, Christian Baerlocher and Lynne McCusker from the Swiss Federal Institute of Technology in Zürich have found a way to orient these tiny crystals. A synchrotron X-ray source can then be used to determine the atomic structure. According the researchers the method “can […]
Galaxies with extremely large redshifts are hard to detect as the radiation they emit shifts to longer wavelengths that are easily absorbed by giant intergalactic hydrogen clouds. Another problem is that their luminosity is dimmed by the vast distances the photons travel, while any radiation that does reach the Earth is absorbed by our atmosphere. […]
The clusters were produced by expanding a deuterium gas jet into a vacuum. A laser beam focussed near the top of the plume heats the clusters, causing them to explode. This creates a small plasma of high energy (keV) deuterium ions which collide with each other and undergo a fusion reaction. The experiment converted laser […]
Governments that have signed the CTBT – which will come into force this September – are concerned that countries such as Iran, India and Iraq might try to develop so called ‘sub-critical’ nuclear tests. These explosions are below the 1 kiloton limit agreed in the CTBT. To check if the 321 seismic stations that make […]
This is not the first time that astronomers have considered using rotating platters of liquid – usually mercury – for a central mirror. For example, a mercury-based telescope would cost one hundredth that of a glass mirror. But previous techniques had one particular flaw – the telescope could not be tilted without destroying the shape […]
The 1860s and 1870s form one of the most exciting periods in physics, probably on a par with the 1920s and 1930s when quantum mechanics was developed. James Clerk Maxwell was working on his theory of the electromagnetic field, Rudolf Clausius introduced the concept of entropy in thermodynamics, and kinetic theory was starting to become […]
As part of the redesign we have also moved the In Depth and Patent News services to the News section, and moved WebWatch to a new expanded Reviews section. We have also put the 1997 and 1998 indexes for Physics World magazine online, and plan to update the 1999 index every month. Those PhysicsWeb users […]
