|Dark Energy Constant! |
Global Warming! Pig Virus! Wal-Mart!
Quantum Bubbles, Cheaper Moon,
Swimming With Dolphins!
|Dark Energy Constant! |
Particle Physics & Astronomy Research Council News Release
November 24, 2005 - The genius of Albert Einstein, who added a "cosmological constant" to his equation for the expansion of the universe but later retracted it, may be vindicated by new research published today in the journal Astronomy and Astrophysics.
The enigmatic "dark energy" that drives the acceleration of the Universe behaves just like Einstein's famed cosmological constant, according to the Supernova Legacy Survey (SNLS), an international team of researchers in France and Toronto and Victoria in Canada, collaborating with large telescope observers in Oxford, Caltech and Berkeley. Their observations reveal that the dark energy behaves like Einstein's cosmological constant to a precision of 10%.
"The significance is huge," said Professor Ray Carlberg of the Department of Astronomy and Astrophysics at the University of Toronto. "Our observation is at odds with a number of theoretical ideas about the nature of dark energy that predict that it should change as the universe expands, and as far as we can see, it doesn't."
Chandra X-Ray Observatory observations include estimates of the
total energy content of the Universe. As shown in this illustration,
dark energy is estimated to contribute about 75% of the energy in
the Universe, dark matter about 21% and normal matter about 4%.
Only the normal matter can be directly detected with telescopes,
and about 85% of this is hot, intergalactic gas, as detected in Chandra
observations of galaxy clusters. (Credit: NASA/ CXC/ M.Weiss)
"We have set ourselves a very challenging goal - to distinguish whether the dark energy can be explained by Einstein's cosmological constant or whether a new physical theory is needed." Says Dr Isobel Hook of the University of Oxford, "So far our results are consistent with Einstein's cosmological constant, but the best is still to come. The first year results already represent the largest homogeneous set of distant supernovae, but over the full five years of the survey we will improve our precision more and more. Our goal is a measurement of the nature dark energy that will be a true legacy for years to come."
She added "Before dark energy was being considered, Einstein invented the 'cosmological constant' to make his equations fit with his ideas about the Universe, but later regretted it, calling it his biggest blunder'. Now we know he may have been closer to the truth than he realised."
The Supernova Legacy Survey (SNLS) aims to discover and examine 700 distant supernovae to map out the history of the expansion of the universe. The survey confirms earlier discoveries that the expansion of the universe proceeded more slowly in the past and is speeding up today, apparently driven by some unknown form of energy. Since scientists don't know much about this mysterious new form of energy, they call it "dark energy."
The researchers made their discovery using an innovative, 340-million pixel camera called Megacam, built by the Canada-France-Hawaii Telescope and the French atomic energy agency, Commissariat à l'Énergie Atomique.
"Because of its wide field of view -- you can fit four full moons in an image -- it allows us to measure simultaneously, and very precisely, several supernovae, which are rare events," said Pierre Astier, one of the scientists with the Centre national de la recherche scientifique (CNRS) in France.
"Improved observations of distant supernovae are the most immediate way in which we can learn more about the mysterious dark energy," adds Richard Ellis, professor of astronomy at the California Institute of Technology. "This study is a very big step forward in quantity and quality."
Study co-author Saul Perlmutter, a physics professor at the University of California, Berkeley, says the findings kick off a dramatic new generation of cosmology work using supernovae.
"The data is more beautiful than we could have imagined 10 years ago -- a real tribute to the instrument builders, the analysis teams and the large scientific vision of the Canadian and French science communities."
The SNLS is a collaborative international effort that uses images from the Canada-France-Hawaii Telescope, a 3.6-metre telescope atop Mauna Kea, a dormant Hawaiian volcano. The current results are based on about 20 nights of data, the first of over nearly 200 nights of observing time for this project.
The researchers identify the few dozen bright pixels in the 340 million to find distant supernovae. They acquire spectra using some of the largest telescopes on Earth--the Frederick C. Gillett Gemini North Telescope on Mauna Kea, the Gemini South Telescope on the Cerro Pachón mountain in the Chilean Andes, the European Southern Observatory Very Large Telescopes (VLT) at the Paranal Observatory in Atacama, Chile, and the Keck telescopes on Mauna Kea.
These still images show the expansion history of the Universe by modeling the Universe as a two-dimensional grid
of galaxies. The Big Bang, shown as a flash of light, is immediately followed by rapid expansion of the Universe. This
expansion then slows down because of the gravitational attraction of the matter in the Universe. As the Universe
expands, the repulsive effects of dark energy become important, causing the expansion to accelerate. (Credit: NASA/
STScI/ G. Bacon)
In the UK the work has been done by Dr Isobel Hook and her student (Justin Bronder) in Oxford. Their focus has been on obtaining spectra with Gemini to measure redshifts and confirm the supernova types. Only certain types of supernovae are useful for cosmology, namely those classed as "Type Ia" which they identify by particular signatures in their spectra.
The "queue" observing mode used at Gemini and VLT is ideal for this project. When they find good supernova candidates from CFHT they send instructions over the internet to the staff at Gemini and VLT, and they take data for them when the weather conditions are right for the program. The instruments used on the Gemini telescopes for this project are the GMOS - the Gemini Multi-object spectrographs - built in the UK (by the UKATC and University of Durham) and Canada.
"Only the world's largest optical telescopes -- with diameters of eight to 10 metres -- are capable of studying distant supernovae in detail by examining the spectrum," said Dr Isobel Hook.
The current paper is based on about one-tenth of the imaging data that will be obtained by the end of the survey. Future results are expected to double or even triple the precision of these findings and conclusively solve several remaining mysteries about the nature of dark energy.
Particle Physics & Astronomy Research Council - http://www.pparc.ac.uk
|Global Warming Doubles Ocean Rise |
Global warming (BBC)
Rutgers University News Release
November 24, 2005 - Global ocean levels are rising twice as fast today as they were 150 years ago, and human-induced warming appears to be the culprit, say scientists at Rutgers, The State University of New Jersey, and collaborating institutions.
While the speed at which the ocean is rising – almost two millimeters per year today compared to one millimeter annually for the past several thousand years – may not be fodder for the next disaster movie, it affirms scientific concerns of accelerated global warming.
In an article published in the Nov. 25 issue of the journal Science, Rutgers professor of geological sciences Kenneth G. Miller reports on a new record of sea level change during the past 100 million years based on drilling studies along the New Jersey coast. The findings establish a steady millimeter-per-year rise from 5,000 years ago until about 200 years ago.
In contrast, sea-level measurements since 1850 from tidal gauges and more recently from satellite images, when corrected for land settling along the shoreline, reveal the current two-millimeter annual rise. "Without reliable information on how sea levels had changed before we had our new measures, we couldn't be sure the current rate wasn't happening all along," said Miller. "Now, with solid historical data, we know it is definitely a recent phenomenon.
"The main thing that's changed since the 19th century and the beginning of modern observation has been the widespread increase in fossil fuel use and more greenhouse gases," he added. "Our record therefore provides a new and reliable baseline to use in addressing global warming."
How global warming happens
The new sea level record spanning 100 million years of geologic time is the first comprehensive one scientists have produced since a commercial research endeavor in 1987, which, according to Miller, was not fully documented and verifiable.
The findings by Miller's team argue against some widely held tenets of geological science. Miller claims, for example, that ocean heights 100 million years ago and earlier were 150 to 200 meters lower than scientists had previously thought. Changes at these levels can only be caused by the Earth's crust shifting on the ocean floor. Miller's findings, therefore, imply less ocean-crust production than scientists had widely assumed.
During the Late Cretaceous period (the most recent age of dinosaurs), frequent sea-level fluctuations of tens of meters suggest that the Earth was not always ice-free as previously assumed. Ice-volume changes are the only way that sea levels could change at these rates and levels, Miller claims.
This suggests small- to medium-sized but short-lived ice sheets in the Antarctic region, and casts doubt whether any of the Earth's warmer eras were fully ice-free.
Miller's team took five 500-meter-deep core samples of sediments onshore along New Jersey's coastline from Cape May to Sandy Hook. The scientists examined the sediment type, fossils, and variations in isotopes, or different forms of the same elements, at different levels in the cores they extracted. Miller also correlated these measurements with others from throughout the world to substantiate the global nature of their record.
The Rutgers study included participants from the New Jersey Geological Survey, the Lamont-Doherty Earth Observatory of Columbia University, Western Michigan University, the University of Oregon and Queens College in Flushing, N.Y. The National Science Foundation provided major funding for the study.
Rutgers University - http://www.rutgers.edu
|Pig Virus! |
Infectious Diseases Society of America News Release
November 23, 2005 - With national attention focused on the avian flu threat, other infections that could be transmitted from animals to people are also coming under scrutiny. People with work exposure to pigs, such as farmers, veterinarians and meat processing workers, are at heightened risk of contracting swine influenza, according to a study in the Jan. 1 issue of Clinical Infectious Diseases, now available online.
Pigs’ physical makeup allows them to contract—and to spread—influenza viruses to and from other species, such as humans and birds.
Due to their susceptibility to influenza virus infections from other species, pigs can also serve as “mixing vessel hosts” that can produce new influenza virus strains that could pose a risk to human health.
In Iowa, the state with the highest swine production, researchers examined farmers, veterinarians, meat processing workers and a control group of people who had no occupational contact with pigs. They discovered that, of the four groups, farmers were most likely to be seropositive—that is, to have antibodies in their blood against swine influenza, indicating previous infection with the virus. Veterinarians also had increased odds of seropositivity. Meat processing workers had elevated antibody levels as well, though the odds were not as high, perhaps due to the workers’ limited exposure to live pigs.
Despite the possibility for human infection with swine influenza, people shouldn’t panic, according to authors Gregory Gray, MD, and Kendall Myers, MS, of the University of Iowa. “While severe swine influenza virus infections in humans have been reported, we expect that the normal clinical course of swine influenza infections [in humans] is mild or without symptoms,” said Dr. Gray.
Pork consumption shouldn’t pose a problem, either. “There’s no evidence to suggest that swine influenza can be transmitted to humans through meat,” Ms. Myers said, so as long as people cook pork thoroughly and practice good handwashing, then pork chops, bacon and ham can stay on the menu.
Because pigs are susceptible to human infections, both the pork industry and swine workers could benefit from the establishment of a human influenza vaccination program. There is no human vaccine against swine influenza at this point, but increasing surveillance for influenza among swine workers is one key component of helping to prevent an epidemic. “Right now, [swine workers] are not included in the national pandemic plan, nor are they closely monitored for influenza,” Dr. Gray said. “Should pandemic influenza virus strains enter the United States and these workers not be given special attention, we think it could be a really big problem for Iowa.”
Founded in 1979, Clinical Infectious Diseases publishes clinical articles twice monthly in a variety of areas of infectious disease, and is one of the most highly regarded journals in this specialty. It is published under the auspices of the Infectious Diseases Society of America (IDSA). Based in Alexandria, Virginia, IDSA is a professional society representing about 8,000 physicians and scientists who specialize in infectious diseases.
Infectious Diseases Society of America - http://www.idsociety.org
|Wal-Mart Shoppers Beware |
Wal-Mart's pricing practices and have led several
Attorneys General to call for an investigation.
WASHINGTON DC November 23, 2005 (U.S. Newswire) - On 'Black Friday,' the traditional kick-off to the Holiday shopping season, WakeUpWalMart.com supporters are mobilizing an unprecedented grassroots campaign informing consumers about two newly released studies showing Wal-Mart charged customers the wrong price in excess of the federal standard in at least 4 states. The studies raise serious questions about Wal-Mart's pricing practices and have led several Attorneys General to call for an investigation.
WakeUpWalMart.com supporters will take part in a national Wal- Mart Consumer Alert campaign by distributing over 1 million flyers in over 36 states and 102 cities.
The 1 million Wal-Mart Consumer Alert flyers announce a new toll free hotline for Wal- Mart customers to call to report being charged the wrong price. The toll-free number is 1-866-253-1350.
"Wal-Mart should not be asking American consumers to gamble with their prices this Holiday season. In at least 4 states, Wal-Mart may need to change its 'Always Low Prices' slogan to 'Sometimes Low Prices, if you are lucky,'" said Paul Blank, campaign director for WakeUpWalMart.com.
Earlier this week, WakeUpWalMart.com and the National Consumers League sent a joint letter to Attorneys General in all 50 states calling on them to launch a full-scale investigation into Wal-Mart's pricing practices based on the findings of two newly released studies conducted by the University of Illinois- Chicago Center for Urban Economic Development and the University of California-Berkeley.
The two studies examined the pricing accuracy, the difference between the shelf-price and the cash register price, at Wal-Mart stores in California, Illinois, Michigan and Indiana and concluded the pricing errors at Wal-Mart stores in these 4 states failed to meet the federal standards set by the National Institute for Standards and Technology (NIST). The federal standard, set by the NIST, requires no more than 2 out 100 randomly selected items from any one store may be incorrectly priced.
The study found that almost 85 percent of the Wal-Mart stores in the IL, MI & IN study failed to meet the federal standard for pricing errors. In California, the results were worse with almost 87 percent of Wal-Mart stores failing to meet the federal standard for pricing accuracy.
"Wal-Mart customers have a right to know whether or not they are paying the wrong price. If a Wal-Mart customer has been charged the wrong price they should call our national Wal-Mart consumer alert hotline," said Paul Blank, campaign director for WakeUpWalMart.com.
In the letter to the Attorneys General, the National Consumers League and WakeUpWalMart.com suggest ways Wal-Mart could correct this potential pricing problem, including: requiring Wal-Mart to post notices at each register warning customers that they may be overcharged; requiring Wal-Mart to hire enough employees to accurately price merchandise; requiring each Wal-Mart store to hire an employee solely responsible to ensure accurate pricing; and require item pricing in its stores.
More info at http://WakeUpWalMart.com
|Quantum Bubbles |
Artist's conception of quantum bubbles (eXoNews)
New Scientist Magazine News Release
By Marcus Chown
November 23, 2005 - As futuristic as quantum computers seem, what with all those qubits and entangled atoms, here is an idea that promises to make atom-based quantum computers look passé even before anyone has built a full-sized version.
It seems that bubbles of electrons lined up in ultracold liquid helium could be used to build a quantum computer capable of carrying out a staggering 1030 simultaneous calculations.
To carry out these simultaneous calculations, quantum computers normally exploit entities such as atoms and molecules, which can be in several quantum states at once, to encode bits in those quantum states – the famous qubits. But Weijun Yao of Brown University in Providence, Rhode Island, wants to replace atoms with curious things called electron bubbles.
To make an electron bubble, start with liquid helium that has been cooled below 2.17 kelvin so that it behaves like a superfluid, a state of matter with zero viscosity. Now inject a fast-moving electron into the superfluid. When the electron eventually slows to a halt after numerous collisions with helium atoms, it creates a cavity about 3.8 nanometres across by repelling nearly 700 atoms' worth of helium around it (New Scientist, 14 October 2000, p 24).
It is this cavity that makes the electron bubble so very valuable. In a quantum computer, the quantum entities need to be isolated from their surroundings to preserve their fragile states. "What could be more isolated than an electron in a bubble?" asks Yao. "The electron inside each bubble interacts very weakly with the background helium atoms."
Yao says 0s or 1s could be encoded in the electrons' spins. In the presence of a magnetic field, the spin can either be parallel or anti-parallel to the field. Crucially, an electron's spin can exist in both states at the same time, enabling the qubit to be both 0 and 1.
According to Yao, large numbers of electrons, each in its own bubble, can be neatly caged using a combination of a device called a linear quadrupole trap, which traps the electrons in a line, and a set of conducting rings, which create a voltage "valley" for each bubble (see Diagram).
All the spins can be initialised to the same value by cooling the apparatus to 0.1 kelvin. You can then manipulate the electrons by applying a combination of a magnetic field gradient along the line and varying the frequency of the voltages in the quadrupole trap. This changes the spin of individual electrons and makes them interact to perform logicgate operations (www.arxiv.org/cond-mat/0510757 ). To read the spin of an electron, the voltage at the end of the electron chain can be lowered so that each bubble drifts in the magnetic field gradient at a velocity that depends on the electron's spin. This drift velocity can be read using lasers.
Because each qubit carries two values, a quantum computer with two qubits could carry out four parallel calculations, one with three qubits eight calculations, and so on. "I see no major technical obstacles to the system I envisage working with 100 qubits," says Yao. "That means it could do 1000 billion billion billion operations all at once."
New Scientist - http://www.newscientist.com
|Cheaper Moon |
On November 16th, 2005 SpaceDev announced its concept for the SpaceDev Dream
Chaser™ vehicle, a six-passenger human space transport that will be much faster
and far less expensive to develop than a new crew launch vehicle as proposed by
large aerospace companies. (SpaceDev)
SpaceDev News Release
POWAY CA November 21, 2005 - SpaceDev announced the results of its International Lunar Observatories Human Servicing Mission, conducted for Lunar Enterprise Corporation.
The study, which was completed in phases over the last three years and presented at the International Lunar Observatory Advisory Committee Workshop held this past weekend, concluded that safe, lower cost missions can be completed by the private sector using existing technology or innovative new technology expected to be available in time for the first mission.
NASA recently announced plans for a Lunar mission expected to cost $104 billion over 13 years. SpaceDev’s results indicate a more comprehensive series of missions could be completed in a fraction of the time for one-tenth of the cost.
SpaceDev's rocket chair (SpaceDev)
Each mission, as envisioned by SpaceDev, would position a habitat module in Lunar orbit or on the moon’s surface. The habitat modules would remain in place after each mission and could be re-provisioned and re-used, thus building a complex of habitats at one or more Lunar locations over time.
“We are not surprised by the significant cost savings that our study concludes can be achieved without sacrificing safety and mission support. Since SpaceDev was founded, our projects and studies have consistently come in at significantly lower costs than those of the large aerospace companies and government agencies,” said SpaceDev founding chairman and chief executive, Jim Benson.
“If we are correct about our Lunar mission cost estimates, our type of human mission could have forty people visiting the Moon for the cost of NASA’s first mission.”
The SpaceDev study creates a conceptual mission architecture and design for a human servicing mission to the Lunar south pole targeted for the period between 2010 and 2015 that would be low in risk and cost.
The length of stay on the Moon will be seven or more days, depending on cost, practicality and other trade-offs. The study explored existing technology, technology currently under development, and proposed technology that could be developed by NASA, other countries or the private sector in time to be incorporated into the mission.
The study divided the missions into segments, for example Earth launch to low Earth orbit (LEO) and to Geo Transfer Orbit (GTO), LEO and GTO to Lunar orbit, Lunar orbit to landing, takeoff to Lunar orbit, Lunar orbit to LEO, and return to Earth from LEO.
The study also concluded that a combination of technology already under development or under consideration by SpaceDev and other companies could be combined to create a growing and lasting presence at the Moon again at costs significantly lower than those proposed by other organizations.
SpaceDev's concept of a lunar colony (SpaceDev)
In addition to existing launch vehicles, components such as the orbital version of SpaceDev’s proposed six passenger Dream Chaser™ vehicle, based on NASA’s HL-20 Personnel Launch System, and hybrid rocket motor modules can provide rapid, cost-effective building blocks to construct a variety of missions.
An exciting concept, borrowed from an early mission design based on sending a Mercury capsule to the Moon, is the “rocket chair” used to land each of the four Lunar visitors.
The rocket chairs as envisioned by SpaceDev would be modular and dual purpose, able to land small Lunar observatories or other science experiments, and could also be used to land individuals from orbit. The rocket chairs have the additional feature of having sufficient propellant to ascend back to the command module for the return trip to Earth.
On the way to the Moon, should a problem develop, the four rocket chairs, attached to the capsule, have sufficient propellant to return the capsule to Earth for a direct atmospheric reentry.
SpaceDev - http://www.spacedev.com
|Swimming With Dolphins Is Good For Depression |
British Medical Journal News Release
November 24, 2005 - Swimming with dolphins is an effective treatment for mild to moderate depression, say researchers in this week's BMJ. Their findings support the theory of biophilia, which shows how human health and wellbeing are dependent on our relationships with the natural environment.
The study was carried out in Honduras and involved 30 patients diagnosed with mild or moderate depression. Half were assigned to the experimental group and half to the control group.
Over a two-week period, participants in the experimental group swam and snorkelled in the water with dolphins for one hour a day. Participants in the control group were assigned to the same water activities, but in the absence of dolphins, to control for the influence of water and the natural setting.
All participants discontinued antidepressant drugs or psychotherapy at least four weeks before entering the study, and were not allowed to take drugs during the study. Depression scores were measured before the study and at the end of treatment.
Although some participants dropped out of the study, the average severity of the depressive symptoms was more reduced in the experimental group than in the control group.
Animal facilitated therapy with dolphins is more effective than water therapy in treating people with mild to moderate depression, say the authors. Despite some study limitations, the effects exerted by the animals were significantly greater than those of just the natural setting.
The echolocation system, the aesthetic value, and the emotions raised by the interaction with dolphins may explain the mammals' healing properties, they suggest.
Three months after the study, participants in both groups also reported lasting improvement and did not require treatment. This suggests that in patients with mild or moderate depression, using drugs or conventional psychotherapy may not be necessary when biophilic treatment with animals is used, they conclude.
BMJ-British Medical Journal - http://www.bmj.com