| Proposal of Smoking Ban Stirs a Sense of Tolerance Talk of a ban on smoking in some outdoor spaces awakened the inner civil libertarian of smokers and nonsmokers alike at City Hall Park. nytimes.com |
Fight to protect California condors from lead ammunition moves to Arizona It has been 22 years since the last 22 California condors ( Gymnogyps californianus ) were collected from the wild and placed in captive breeding programs. The species, which nearly went extinct due to habitat loss, poaching, DDT and lead poisoning, has since rebounded to 332 birds, according to counts maintained by the Zoological Society of San Diego . But despite that conservation success, condors still face a major threat from lead poisoning, which often occurs when the birds eat carcasses killed by hunters' lead ammunition. [More] rss.sciam.com |
Smallest Farmers Key to Feeding World's Poorest How can we feed the world? It’s a key question for the 21st century, one that vexes scientists, policy makers and, of course, farmers. In a paper in the February 12th issue of the journal Science , researchers warn that unless the focus is on helping small farmers in developing countries, the efforts to feed all the world’s people will most likely fail.These small-scale farmers may raise just a few crops and graze a handful of animals. They’ve been mostly ignored by agricultural assistance agencies--but according to the researchers, these farmers feed most of the world’s poorest billion people. They face challenges from an increasing population; land that’s overfarmed and worn out; and climate change, bringing with it worsening drought or increased rainfall. [More] rss.sciam.com |
Readers Respond on "Looking for Life in the Multiverse" Life, the Multiverse and Everything In “ Looking for Life in the Multiverse ,” Alejandro Jenkins and Gilad Perez say that life would be possible in a universe without the weak nuclear force. But they fail to note that the weak force is unique in treating matter and antimatter asymmetrically. Only because of this asymmetry did matter slightly outweigh antimatter before nearly all antimatter annihilated with an equal amount of matter, within the first seconds after the big bang. Everything we see--including stars, which are essential to life--is composed of that slight excess of matter. A universe without the asymmetric weak force would have virtually no normal matter and hence no life in any form we might recognize. [More] Big Bang - Antimatter - Matter - Universe - Cosmology rss.sciam.com |
Just How Small is the Proton? Physicists have been scratching their heads since July, when a research team announced that the proton, the basic building block of matter, is 4 percent smaller than previously thought. The finding, published in Nature , clashes with theoretical predictions based on quantum electrodynamics, or QED, the fundamental theory of the electromagnetic force that had passed the most stringent tests in physics.Randolf Pohl of the Max Planck Institute for Quantum Op­tics in Garching, Germany, and his collaborators used a laser to probe exotic, man-made hydrogen atoms in which elementary particles known as muons replaced the usual electrons orbiting the single-proton nuclei. Laser energy made the atoms fluoresce at char­acteristic x-ray wavelengths. Those wavelengths reflected a number of subtle effects, including the little known fact that an orbiting particle--be it a muon or an electron--often flies straight through the proton. That is possible because protons are composed of smaller elementary particles (mainly three quarks), and most of the space inside a proton is actually empty. [More] Physics - Quantum electrodynamics - Elementary particle - Quantum mechanics - Proton rss.sciam.com |