A light bulb isn’t very useful without a reliable on/off switch. The same holds true for quantum dots. These ultra tiny electronic nanostructures someday may serve as the ones and zeros used by a superfast quantum computer, but first physicists need to refine their ability to turn quantum dots “on” and “off.”
In the June 23, 2003, on-line issue of Applied Physics Letters, researchers from the National Institute of Standards and Technology (NIST) and the National Renewal Energy Laborato
Engineers at the University of California, Berkeley, have found an innovative way to grow silicon nanowires and carbon nanotubes directly on microstructures in a room temperature chamber, opening the doors to cheaper and faster commercialization of a myriad of nanotechnology-based devices.
The researchers were able to precisely localize the extreme heat necessary for nanowire and nanotube growth, protecting the sensitive microelectronics – which remained at room temperature – just a few mic
The Northern Lights are a visible result of physical processes in inner space. By studying the optical signal from the Northern Lights and similar phenomena, we can gain new knowledge about the physics behind them. In the long run such pure research may be of great importance for applications in our future supply of energy and for future space travel.
A dissertation at Umeå University, Sweden, by researcher Urban Brändström at The Swedish Institute of Space Physics, focuses on the constructi
Dutch physicists from Leiden University have made an experimental laser that combines the advantages of two types of laser. With the experimental laser, which generates light in a sort of billiards table with round edges, the researchers have demonstrated that is possible to produce cheaper lasers.
A conventional laser reflects light between two very accurately positioned mirrors, the so-called resonant cavity. The distance between the mirrors determines which wavelength is amplified and th
The instruments on board ESA’s mission to Mars, Mars Express, are in the process of being tested to verify that they have survived the launch successfully and will work properly. One of these tests on the Mars Express lander, Beagle 2, has been postponed to the first week of July.
This will give engineers extra time to investigate a temporary anomaly that occurred in a memory unit, the so-called “Solid State Mass Memory” (SSMM). The SSMM stores data from the instruments before sending t
With the help of ultrafast lasers, Dutch researcher Anouk Wetzels from the FOM Institute for Atomic and Molecular Physics has visualised the wave function of slow electrons. The wave function describes how the electron moves around the nucleus of an atom. With this it is possible to directly visualise atomic and even molecular wave functions.
Wetzels used light pulses with a duration of a millionth of a millionth of a second to visualise the wave function of electrons in atoms. With these
Clearest-Ever Evidence from VLT Spectra of Powerful Event
A very bright burst of gamma-rays was observed on March 29, 2003 by NASA’’s High Energy Transient Explorer (HETE-II), in a sky region within the constellation Leo.
Within 90 min, a new, very bright light source (the “optical afterglow”) was detected in the same direction by means of a 40-inch telescope at the Siding Spring Observatory (Australia) and also in Japan. The gamma-ray burst was designated GRB 030329, acco
First detection by infrared interferometry of an extragalactic object
Active galactic nuclei (AGN) are one of the most energetic and mysterious phenomena in the universe. In some galaxies indeed, the core generates amounts of energy which surpass those of normal galaxies, such as the Milky Way, by many orders of magnitude.
The central engine of these power stations is thought to be a supermassive black hole. Indirect lines of evidence have suggested that these massive black
NASA and university astronomers have found evidence the 11-year sunspot cycle is driven in part by a giant conveyor belt-like, circulating current within the Sun.
The astronomers, Dr. David Hathaway, Robert Wilson and Ed Reichmann of NASA’s Marshall Space Flight Center in Huntsville, Ala., and Dr. Dibyendu Nandy of Montana State University in Bozeman, reported their findings the week of June 16 at the annual meeting of the Solar Physics Division of the American Astronomical Soci
Using images from the Hubble Space Telescope, astronomers have concluded that two of the most common types of galaxies in the universe are in reality different versions of the same thing. In spite of their similar-sounding names, astronomers had long considered “dwarf elliptical” and “giant elliptical” galaxies to be distinct objects. The new findings, which appear in this month’s edition of The Astronomical Journal, fundamentally alter astronomers’ understanding of these important components of th
Fifteen days after the launch of Mars Express, Europe has reaffirmed its trust in Soyuz: next stop Venus in 2005!
Just two weeks after the flawless launch of Mars Express on its way towards the Red Planet, ESA and the European-Russian company Starsem reinforced their relationship with the signature of the Venus Express launch services agreement.
The contract was signed at Le Bourget (Paris) Air Show, Tuesday, 17 June 2003, by David Southwood, Director of Science for the European Sp
Multi-National team of physicists include Weizmann Institute Scientists
Recent results of a joint experiment conducted by 460 physicists from 57 research institutions in 12 countries strongly indicate that the scientists have succeeded in reproducing matter as it first appeared in the universe; this matter is called the quark-gluon plasma. The experiment, called PHENIX and conducted at the Brookhaven National Laboratory on Long Island, New York, has brought together physicists from Br
Using the superior sensitivity of ESA’s X-ray observatory, XMM-Newton, a team of European astronomers has made the first direct measurement of a neutron star’s magnetic field.
The results provide deep insights into the extreme physics of neutron stars and reveal a new mystery yet to be solved about the end of this star’s life.
A neutron star is very dense celestial object that usually has something like the mass of our Sun packed into a tiny sphere only 20–30 km across. It is the p
Physicists at Ohio State University may have explained some strange behavior of the ultra-cold material known as Bose-Einstein condensate (BEC).
The new analysis shows that scientists are closer than ever to harnessing BEC to perform useful functions such as quantum computing, said Tin-Lun Ho, professor of physics at Ohio State and the project’s principal investigator.
Ho has pioneered theoretical studies of BEC, an entirely new form of matter that defies description as
VLT Interferometer Measurements of Achernar Challenge Stellar Theory
To a first approximation, planets and stars are round. Think of the Earth we live on. Think of the Sun, the nearest star, and how it looks in the sky.
But if you think more about it, you realize that this is not completely true. Due to its daily rotation, the solid Earth is slightly flattened (“oblate”) – its equatorial radius is some 21 km (0.3%) larger than the polar one. Stars are enormous gaseous spheres
A team of astrophysicists at the University of the Basque Country has detected, for the first time ever, changes in Saturn’s winds. The research has merited front page coverage in the scientific magazine, Nature.
The winds blowing around Saturn and Jupiter are special. Unlike those of the rest of the planets, these move in an eastwards direction and are ten times stronger than the earth’s winds. On our planet it is solar radiation which governs the winds, but on the distant planets it is bel
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