Research paves the way to next generation of ’atomic clocks’
Three of the world’s premier measurement laboratories – including the Commerce Department’s National Institute of Standards and Technology (NIST) – have lined up the “hash marks” from four of the world’s best optical frequency rulers and declared that they match. The experiments, reported in the March 19, 2004, issue of the journal Science, are a significant step toward next-generation “atomic clocks
The number of applications requiring random numbers increases continuously. They are used for example in cryptographic applications to guarantee the secrecy of electronic communications, in scientific calculations or in chance games and lotteries. In spite of this, their generation remains a difficult task. The Group of Applied Physics and the Computer Science Department of the University of Geneva team with the company id Quantique to launch the first website allowing to download random numbers from
Thanks to ESA’s Mars Express, we now know that Mars has vast fields of perennial water ice, stretching out from the south pole of the Red Planet.
Astronomers have known for years that Mars possessed polar ice caps, but early attempts at chemical analysis suggested only that the northern cap could be composed of water ice, and the southern cap was thought to be carbon dioxide ice.
Recent space missions then suggested that the southern ice cap, existing all year round, could be a mixture
Physicists in New Zealand have shown that last November’s record-breaking solar explosion was much larger than previously estimated, thanks to innovative research using the upper atmosphere as a gigantic x-ray detector. Their findings have been accepted for 17 March publication in Geophysical Research Letters, published by the American Geophysical Union.
On 4 November 2003, the largest solar flare ever recorded exploded from the Sun’s surface, sending an intense burst of radiation
On Friday, 12 March 2004, the Sun ejected a spectacular ’eruptive prominence’ into the heliosphere. SOHO, the ESA/NASA solar watchdog observatory, faithfully recorded the event.
This ’eruptive prominence’ is a mass of relatively cool plasma, or ionised gas. We say ’relatively’ cool, because the plasma observed by the Extreme-ultraviolet Imaging Telescope (EIT) on board SOHO was only about 80 000 degrees Celsius, compared to the plasma at one or two milli
Talk about precision. New measurements of key wavelengths of ultraviolet light — down to a few millionths of a nanometer — are among the most precise ever reported and are improving calibrations of microlithography tools used in making integrated circuits such as those in computer chips.
The dimensions involved are 10,000 times smaller than hydrogen atoms, the smallest of all atoms.
To make the measurements, physicists at the National Institute of Standards and Technolo
ESA PR 15-2004. Today the Rosetta Science Working Team has made the final selection of the asteroids that Rosetta will observe at close quarters during its journey to Comet 67P/Churyumov-Gerasimenko. Steins and Lutetia lie in the asteroid belt between the orbits of Mars and Jupiter.
Rosetta’s scientific goals always included the possibility of studying one or more asteroids from close range. However, only after Rosetta’s launch and its insertion into interplanetary orbit could the
Astronomers today unveiled the deepest portrait of the visible Universe ever achieved by humankind. Called the Hubble Ultra Deep Field (HUDF), the million-second-long exposure reveals the first galaxies to emerge from the so-called ’dark ages’, the time shortly after the ’Big Bang’ when the first stars reheated the cold, dark Universe. The new image should offer unprecedented insights into what types of objects reheated the Universe long ago.
This historic new view is actually made up by t
The Chandra X-ray Observatory is a space observatory dedicated to X-ray astronomy. Launched on July 23rd, 1999, this X-ray telescope is particularly dedicated to the observation of high-energy sources in the universe. It has also been used to study the following solar system objects: the Moon, Venus, Mars, Jupiter, and even the Comet C/1999 S4 LINEAR.
Using Chandra, J.-U. Ness and his colleagues detected an unambiguous X-ray emission from the planet Saturn for the first time. A few years a
Ann Nguyen chose a risky project for her graduate studies at Washington University in St. Louis. A university team had already sifted through 100,000 grains from a meteorite to look for a particular type of stardust — without success.
In 2000, Nguyen decided to try again. About 59,000 grains later, her gutsy decision paid off. In the March 5 issue of Science, Nguyen and her advisor, Ernst K. Zinner, Ph.D., research professor of physics and of earth and planetary sciences, both in Arts & Sc
A new study by theoretical physicists at the University of Toronto and the University of California at Los Angeles (ULCA) could bring scientists one step closer to the dream of a superconductor that functions at room temperature, rather than the frigid temperatures more commonly found in deep space.
The findings, which appear in the March 4 issue of the journal Nature, identify three factors that explain a perplexing pattern in the temperatures at which multi-layered ceramic materials become
Using a British radio telescope called the Very Small Array (VSA), located on the flanks of Mount Teide in Tenerife, astronomers from the Universities of Manchester and Cambridge and the Instituto de Astrofisica de Canarias (IAC) have made measurements of the Cosmic Microwave Background (CMB) – radiation left over from the Big Bang – which shed new light on events in the first minute fraction of the Universe’s existence.
By combining their results with those of NASA’s Wilkinson Microwa
The need for advanced highly integrated photonic circuits stems from the capacity expansion of telecommunications infrastructures driven by ever-increasing customer demand. Novel design and manufacturing technologies for advanced photonic circuits emerging from PICCO could meet this need.
Ready for mass production
The work of the IST programme-funded project has provided evidence that functional photonic circuits can be created using state-of-the-art deep UV lithography. T
“Starry Night”, Vincent van Gogh’s famous painting, is renowned for its bold whorls of light sweeping across a raging night sky. Although this image of the heavens came only from the artist’s restless imagination, a new picture from the NASA/ESA Hubble Space Telescope bears remarkable similarities to the Van Gogh work, complete with never-before-seen spirals of dust swirling across trillions of kilometres of interstellar space.
This image, obtained with the Advanced Camera for Surveys on 8
In the morning of March 2, the Rosetta spacecraft was launched on board an Ariane-5 launcher from the European Spaceport in Kourou, French Guiana. The European Space Agency (ESA) spacecraft will be the first to land on a comet.
Before the launch, and as a salute to their colleagues at ESA, astronomers used the New Technology Telescope at the European Southern Observatory (ESO) of La Silla in Chile to image Rosetta’s target, Comet 67P/Churyumov-Gerasimenko, an approximately 4 kilometre size
Physical Review E publishes paper on fusion experiment conducted with upgraded measurement system
Physical Review E has announced the publication of an article by a team of researchers from Rensselaer Polytechnic Institute (RPI), Purdue University, Oak Ridge National Laboratory (ORNL), and the Russian Academy of Science (RAS) stating that they have replicated and extended previous experimental results that indicated the occurrence of nuclear fusion using a novel approach for plasma co
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