Their technique works by using a process called two-colour holography. One wavelength of light records information on the crystal and another is used to read the data. Their method fires two light sources at the same time at the target. The researchers doped a lithium niobate crystal with iron and manganese to create two different […]
The researchers cooled the manganese oxide compound (Pr0.7Ca0.3MnO3) to below 200 K in a zero magnetic field. At this temperature the electrons drop into a low energy state, which minimizes their natural repulsion. The material is usually an insulator, but previous experiments indicated that it can be transformed to a conductor by using X-rays, visible […]
Carbon nanotubes – which can be thought of as a rolled-up graphite sheet – were discovered in 1991. One way to produce large quantities of nanotubes is to place two water-cooled carbon electrodes 1mm apart in a vacuum chamber filled with an inert gas such as argon. A high-current arc between the electrodes creates nanotubes […]
Researchers are investigating new ways to make computer chips in an effort to increase processing speed. It is likely that these new methods, such as chemical fabrication and assembly, will produce large numbers of defective chips. Rather than throw these chips away, James Heath of UCLA and colleagues at Hewlett-Packard are investigating how to build […]
The crossword puzzle was created using a software package developed by Lewis. The instructor simply types the clues and their answers into the program, which then creates the crossword grid. Although the students are given a hard copy of the puzzle, they have to enter their solutions over the Internet with a Java capable browser […]
The Doomsday Clock was set up in 1947 by atomic scientists concerned at the growing nuclear tensions between the US and Soviet Union. Initially the clock read seven minutes to midnight, and moved to two minutes to midnight after the first hydrogen bombs were tested. Until yesterday the time on the clock was 14 minutes […]
The hacker or hackers managed to gain password access to SLAC by intercepting the username and password of a registered user accessing data inside SLAC’s firewall. The random behaviour of the hackers inside the SLAC network suggests that they were trying to gain access to other government and university servers rather than access SLAC data. […]
William Van Vorst of the University of California at Los Angles and Addison Bain, an independent consultant, have gathered evidence that hydrogen could not have caused the explosion. Film footage and witnesses of the crash describe bright yellow flames burning downwards, but hydrogen would only burn in an upward direction with a colourless flame. Several […]
The 2.5 m Sloan telescope is based at Apache Point Observatory in New Mexico. The telescope has an unusually wide field of view and one of the most advanced digital cameras ever built. The camera consists of 30 charge-coupled devices (CCDs), each containing four million picture elements. One night’s observing will produce up to 200 […]
Neutrinos come in three types – electron neutrinos, muon neutrinos and tau neutrinos – and only interact very weakly with matter, which makes them extremely difficult to detect. Neutrino detectors have to be built underground to isolate them from cosmic rays. Even then natural radioactivity from the detector itself can mimic a neutrino interaction, so […]
