Infinite doppelgängers may explain quantum probabilities
NewScientist.com: An identical copy of you is also reading this story. This twin is the same in every way, living on an Earth and in a universe that looks exactly like our own. And there may be an infinite number of them. Such doppelgängers could be a natural consequence of our present conception of the universe. Now, some physicists say they could pose a serious problem for quantum mechanics. But a possible fix may also be in sight, and it could help tie abstract quantum concepts to concrete physical causes.
At issue is the possibility that there could be a multiplicity of copies of any particular experiment floating about the universe, just as there could be a multiplicity of yous. There could even be an infinite number of them if, as is thought, the early universe underwent a period of exponential growth, called inflation.
NASA/NOAA Study Finds El Niños are Growing Stronger
NASA Jet Propulsion Laboratory, California Institute of Technology: A relatively new type of El Niño, which has its warmest waters in the central-equatorial Pacific Ocean, rather than in the eastern-equatorial Pacific, is becoming more common and progressively stronger, according to a new study by NASA and NOAA. The research may improve our understanding of the relationship between El Niños and climate change, and has potentially significant implications for long-term weather forecasting.
Lead author Tong Lee of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., and Michael McPhaden of NOAA’s Pacific Marine Environmental Laboratory, Seattle, measured changes in El Niño intensity since 1982. They analyzed NOAA satellite observations of sea surface temperature, checked against and blended with directly-measured ocean temperature data. The strength of each El Niño was gauged by how much its sea surface temperatures deviated from the average. They found the intensity of El Niños in the central Pacific has nearly doubled, with the most intense event occurring in 2009-10.
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Time to blame climate change for extreme weather?
NewScientist.com: It is time to start asking the hard questions. Countless people in flood-stricken Pakistan have lost families and livelihoods. Who can they hold responsible and turn to for reparations?
Less than a decade ago, these questions would have been dismissed outright. “Many scientists at the time said that you can never blame an individual weather event on climate change,” says Myles Allen of the University of Oxford. But a small meeting of scientists in Colorado last week – organised by the US National Oceanic and Atmospheric Administration, the UK Foreign and Commonwealth Office and the UK Met Office’s Hadley Centre, among others – suggests the tide is turning.
The aim of the Attribution of Climate-Related Events workshop was to discuss what information is needed to determine the extent to which human-induced climate change can be blamed for extreme weather events – possibly even straight after they have happened.
Assigning blame in this way is not without precedent. In 2004, Allen and his colleagues showed to a high level of confidence that human greenhouse gas emissions had at least doubled the risk of the European heatwave of 2003 occurring.
The Story of Cosmetics: How safe are they really?
SafeCosmetics.org: Brought to you by the makers of “The Story of Stuff,” this video describes what’s really in our personal care products, the potential risks they carry by their daily use, and how we can make improvements and cut risks by making wiser choices.
EarthTalk: Radiation Exposure From CT Scans; and Returning Predators to the Wild
Dear EarthTalk: Should I fear radiation exposure associated with medical scans such as CT scans, mammograms and the like?
– Shelly Johansen, Fairbanks, AK
The short answer is…maybe. Critics of the health care industry postulate that our society’s quickness to test for disease may in fact be causing more of it, especially in the case of medical scans. To wit, the radiation dose from a typical CT scan (short for computed tomography and commonly known as a “cat scan”) is 600 times more powerful than the average chest x-ray.
Critics of the health care industry
postulate that our society’s quickness
to test for disease may in fact be
causing more of it, especially in the
case of medical scans. The radiation
dose from a typical CT scan is 600
times more powerful than the average
chest x-ray.
Photo credit: Getty Images
A 2007 study by Dr. Amy Berrington de González of the National Cancer Institute projected that the 72 million CT scans conducted yearly in the U.S. (not including scans conducted after a cancer diagnosis or performed at the end of life) will likely cause some 29,000 cancers resulting in 15,000 deaths two to three decades later. Scans of the abdomen, pelvis, chest and head were deemed most likely to cause cancer, and patients aged 35 to 54 were more likely to develop cancer as a result of CT scans than other age group.
Another study found that, among Americans who received CT scans, upwards of 20 percent had a false positive after one scan and 33 percent after two, meaning that such patients were getting huge doses of radiation without cause. And about seven percent of those patients underwent unnecessary invasive medical procedures following their misleading scans. CT scans are much more common today than in earlier decades, exacerbating the potential damage from false positives and excessive radiation exposure.
“Physicians and their patients cannot be complacent about the hazards of radiation or we risk creating a public-health time bomb,” says Dr. Rita Redberg, a cardiologist at University of California-San Francisco. “To avoid unnecessarily increasing cancer incidence in future years, every clinician must carefully assess the expected benefits of each CT scan and fully inform his or her patients of the known risks of radiation.”
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Americans Using Less Energy, More Renewables
Lawrence Livermore National Laboratory: Americans are using less energy overall and making more use of renewable energy resources.
The United States used significantly less coal and petroleum in 2009 than in 2008, and significantly more wind power. There also was a decline in natural gas use and increases in solar, hydro and geothermal power according to the most recent energy flow charts released by the Lawrence Livermore National Laboratory.
“Energy use tends to follow the level of economic activity, and that level declined last year. At the same time, higher efficiency appliances and vehicles reduced energy use even further,” said A.J. Simon, an LLNL energy systems analyst who develops the energy flow charts using data provided by the Department of Energy’s Energy Information Administration. “As a result, people and businesses are using less energy in general.”
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Is quantum theory weird enough for the real world?
NewScientist.com: Physics, its practitioners will proudly tell you, is the most fundamental of sciences. Its theories and laws distil the workings of the real world – of particles and planets, heat and light – into stark, sweeping statements of universal validity. Think Newton’s law of gravity, which describes with equal assurance how an apple falls and Earth orbits the sun, or the laws of thermodynamics that govern how energy flows. These physical laws are generally couched in the language of mathematics, to be sure. But this is merely a convenient shorthand. The mathematical quantities are ciphers, proxies for the tangible objects of the real, physical world and their measurable properties.
That was all true until quantum theory arrived on the scene. Quantum theory is odd, not just because its weird predictions are a source of consternation for physicists and philosophers, but because its mathematical structures bear no obvious connection to the real world, as far as we can see. “We do not have a source for the mathematical formalism of quantum mechanics,” says Časlav Brukner of the University of Vienna in Austria. “We do not have a nice physically plausible set of principles from which to derive it.”