Updated: 2012-08-31 21:20:36
Some links of mathematical interest that I’ve recently run across: The life and work of Alexander Grothendieck is one of the great stories of modern mathematics. Winfried Scharlau’s first volume of a biography of Grothendieck, covering the years up to … Continue reading →
Updated: 2012-08-30 22:30:00
Vast swaths of reddish-
brown pines dominate the landscape on the trails of Yellowstone National Park in Wyoming and down ski runs around Aspen, Colorado. The morbid color, by now a staple of the Rockies, comes not from fire or some exotic disease but from an insect no larger than a grain of rice—the bark beetle.
North American foresters have tracked the invasive bark beetle for centuries, but in the last 15 years its numbers have exploded. Beetles are now wiping out trees, even whole forests, at an unprecedented pace; they ravaged 9.2 million acres of forest in the western United States in 2010, according to the Forest Service, three times as much as that destroyed by fire. In British Columbia, the devastation over the last decade covers an area larger than Florida.
Until recently there was virtually nothing landowners could do to protect even small parcels of forest from bark beetles. But after a half century of detective work, a small group of scientists has come up with a novel and surprisingly effective means of defense: hijacking the beetles’ sense of smell.
Like ants and honeybees, beetles communicate via scented chemicals called pheromones, one of which warns the insects to stay away from particular trees. Now researchers are dispersing this pheromone, called verbenone, placing a molecular shield over thousands of acres of hardy green pines in western ski resorts, nature reserves, and campgrounds. “Verbenone is just fantastic,” says David Wood, a retired forest entomologist at the University of California, Berkeley. “It’s the only effective treatment, period...”
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Image: Shutterstock
Updated: 2012-08-29 02:19:17
Via the Quantum Pontiff, news that the Simons Foundation will be providing up to $300,000 in financial support to the arXiv for each of the next five year. Last year, the arXiv announced a $60K planning grant from Simons. Now … Continue reading →
Updated: 2012-08-28 15:30:00
Robert Full’s lab is brimming with critters in motion: scuttling crabs, crawling centipedes, prowling geckos. These animals serve as inspiration as he and his colleagues at the University of California, Berkeley, build robots that are fast, steady, and agile. In January, Full used his analysis of leaping lizards to design a rugged bot that can navigate through the rubble following an earthquake or other disaster...
Image: On your mark, get set, go! Tailbot may not have the speed of an agama lizard (left) or an extinct velociraptor (right), but it is just as adept at maneuvering its tail in midair to set up a perfect landing. Dr Torsten Wittmann/Science Photo Library
Updated: 2012-08-25 19:47:03
Andrei Linde is one of Yuri Milner’s $3 million dollar men, best known for his “chaotic inflation” version of inflationary theory, as well as being one of the main proponents of anthropic multiverse mania. There’s a long piece based on … Continue reading →
Updated: 2012-08-24 15:30:00
Five years ago, the Minnesota Pork Producers Association came to agricultural engineer Chuck Clanton with a bizarre problem: The manure pits where farmers store pig waste were exploding. Some of the blasts raised roofs and shattered windows on the buildings that housed the pits. Others leveled entire structures. One explosion in Iowa killed 1,500 pigs and put a farmer in the hospital. What, the trade group wanted to know, was causing these mysterious explosions...
Image: A foaming manure pit—prelude to an explosion? Courtesy University of Minnesota
Updated: 2012-08-23 16:50:00
Here’s a thought experiment for you:
If someone told you you had to drink just one kind of alcoholic beverage for the rest of your life, and you wanted that life to be long and healthy, what would you pick? Wine, right? After all, you’ve probably heard about the scientific studies showing that drinking wine is associated with better health in general, and a longer life span in particular. Give jocks their beer and lushes their hard liquor; the drink of robust, long-lived people is wine.
But you have probably not heard about another study, released during the media dead zone just after Christmas last year, that questioned wine’s reputed health effects. Researchers at Stanford University and the University of Texas at Austin examined a group of Americans aged 55 to 65 and compared their drinking habits with how they fared over the course of 20 years. The scientists found that moderate drinkers lived longer than abstainers, and that wine drinkers did indeed live longer on average than people who consumed other kinds of alcohol. But they also found that wine drinkers were less likely to smoke, to be male, and to be sedentary; all of these are factors associated with dying earlier.
The Stanford-Texas team concluded that drinking wine might be an indicator of a healthy lifestyle rather than the cause of that good health. If so, wine is the drink of the healthy, all right—the already healthy.
That finding highlights what is arguably science’s greatest enemy, the confounder. Science is at heart a reductionist process: Take a complicated system, identify various factors that affect the system, and measure the effect of each factor one at a time. Confounders are devilish hidden connections that make it more difficult to isolate the factors you want to measure, like the fact that wine drinkers tend also to be nonsmokers.
Researchers are continually trying to root out confounders and account for them in their data...
Illustration by Bruno Mallart
Updated: 2012-08-21 05:42:21
The Higgs suggests that there could be more dimensions of space-time than we previously thought. From a New Yorker piece this week (subscription required) about Joe Incandela of CMS and the Higgs discovery. Even the famed New Yorker fact-checkers are … Continue reading →
Updated: 2012-08-17 16:55:24
The LHC is operating well, hitting record peak luminosities, with integrated luminosity for the year over 11 fb-1. By the end of the year there may be 25 fb-1 per experiment or so. Current plan seems to be to update … Continue reading →
Updated: 2012-08-15 18:31:13
This post was originally going to be just about the latest SUSY exclusion results announced at SUSY 2012 and their significance, but I realized there’s nothing much new to say, and it would be tedious to just write the same … Continue reading →
Updated: 2012-08-15 13:34:54
Updated: 2012-08-13 19:51:19
Gerard ’t Hooft in recent years has been pursuing some idiosyncratic ideas about quantum mechanics; for various versions of these, see papers like this, this, this and this. His latest version is last month’s Discreteness and Determinism in Superstrings, which … Continue reading →
Updated: 2012-08-11 12:55:00
Out beyond the orbit of Mars lie fragments of worlds that might have been. Back when Earth was still forming and the moon was a molten ball—some 4.5 billion years ago—the chunks of rock and ice there never moved on to bigger things. The solar system probably would have ended up with a few more planets as large as Earth had not Jupiter’s immense gravitational sway hurled those building blocks apart before they could come together. Today more than a million remnants of that stalled genesis survive, making up the ragged asteroid belt between Mars and Jupiter.
Some 40 percent of the belt’s total mass is concentrated in just two asteroids, Ceres and Vesta—the ones that came closest to growing up. Ceres is so big that six years ago the International Astronomical Union upgraded its status to “dwarf planet,” putting it on equal footing with Pluto. Vesta, though a shade smaller, is in some ways even more deserving of the title, sharing many of the geological qualities that define Earth, Mars, and the other inner planets. And yet both asteroids were, until very recently, entirely unexplored.
“They are the most massive bodies between the sun and Neptune that have not been visited by a spacecraft,” says Marc Rayman, the chief engineer for a NASA mission dedicated to addressing that lapse.
The Dawn spacecraft—so named because it will give scientists their first close look at two relics from the very beginning of the solar system—took off from Cape Canaveral atop a Delta II rocket in September 2007. It settled into orbit around Vesta last summer; in late August it is scheduled to leave the asteroid and begin a two-and-a-half-year voyage to Ceres.
Dawn is a mission two centuries in the making...
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Updated: 2012-08-09 23:56:08
Over at HuffPo, my colleague Nick Warner has posted a piece about why we teach algebra to people who supposedly “won’t need it”, and he makes some excellent points. (Recall the silly New York Times piece by Andrew Hacker entitled “Is Algebra Necessary?” that I mentioned a few posts ago.)
I recommend Nick’s piece.
-cvj
Updated: 2012-08-09 15:06:45
For many years now discussion in the HEP community of what might be the appropriate next machine to try and finance and build after the LHC has centered around the idea of a linear electron-positron collider. The logic has been … Continue reading →
Updated: 2012-08-09 14:15:00
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Updated: 2012-08-08 14:25:00
Perla Lewis-Truong’s due date was March 1. But the day after Thanksgiving, she was admitted to the hospital with severe preeclampsia, a disorder marked by a rapid rise in blood pressure that puts a mother’s health and pregnancy at risk. A week later doctors had to deliver her daughter by cesarean section, 13 weeks early. Baby Celia weighed only a pound and a half. After two months, she is four pounds and still nearly translucent but healthy, lying in a small heated pod in the Children’s Hospital of the University of California, Davis, in Sacramento. Celia was lucky to be born here, at a teaching hospital with an advanced neonatal intensive care unit. Premature babies face many potential problems, including necrotizing enterocolitis, in which intestinal walls deteriorate and bacteria invade. A quarter of infants with the disease die, and survivors may suffer neurological problems for years.
Mark Underwood, a neonatologist at U.C. Davis, is constantly seeking better treatments for his delicate patients. Contrary to traditional practice, his focus is not on drugs but on diet. Underwood believes that many cases of necrotizing enterocolitis could be prevented by giving preemies a special daily cocktail of probiotics (healthy bacteria) and prebiotics (the food those bacteria eat), all inspired by what might be considered the ultimate superfood: human milk.
“Milk is powerful as a preventer of disease and an enhancer of
performance,” says Bruce German, a food chemist at U.C. Davis. “By understanding how it does what it does, we can bring the principles, the mechanisms of action, and the benefits to everyone.” Human milk’s most important role could be preventing infant disease and boosting immunity by cultivating a balance of microbes in the gut and the rest of the body, a kind of internal ecosystem called the microbiome. In fact, many researchers now believe that mammalian lactation originally evolved as a protective, not a nutritional, adaptation...
Image: iStockphoto
Updated: 2012-08-06 15:25:00
Earth’s modern continents are the fragments of a single, 300-million-year-old supercontinent called Pangaea. This vast landmass once rested on the equator, near where Africa is today. During the age of dinosaurs, tectonic forces slowly tore Pangaea apart. Now geologists predict those same forces will reassemble the pieces into a new supercontinent, named Amasia, about 100 million years in the future.
Ancient rocks and mountain ranges show that the constant movement of Earth’s crust has assembled and ripped apart supercontinents several times before, in a roughly half-billion-year cycle. But pinpointing where the past ones formed has proven difficult, which in turn clouded attempts to forecast the next great smashup.
A team of Yale geologists say they have cracked the problem, providing the best look yet at the planet of a.d. 100,000,000. Led by graduate student Ross Mitchell, the researchers first looked back beyond Pangaea and determined the location of supercontinents Rodinia, which formed about a billion years earlier, and Nuna, 700 million years before that. The team found that during the last two cycles, each supercontinent formed a quarter of the way around the globe from where the previous supercontinent had been. Using that insight, they calculated that Amasia will form over the North Pole...
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Image: Today's continents (left) will almost all migrate toward the North Pole and crash together to form a new landmass called Amasia (right). trevorjohnston.com
