Saturday, April 17, 2010
Thursday, April 1, 2010
How about running 47 miles in shoe-melting heat with just tire rubber strapped to your feet? A top American ultramarathoner ventures deep into Mexico’s Copper Canyons to learn the secrets of the Tarahumara, the world’s greatest runners.
Text and photographs by Will Harlan
Last March, I journeyed deep into the Copper Canyons of northwest Mexico to run with the indigenous Tarahumara, widely regarded as the world’s greatest endurance athletes. Made famous recently by Christopher McDougall’s bestselling book Born to Run, the Tarahumara scratch a living out of barren, rocky soil, growing ancient varieties of corn and beans. Most live in caves and tiny huts scattered throughout four monstrous, river-carved chasms—each deeper than the Grand Canyon. Through steep canyons and blistering heat, they run—wearing hand-made sandals called huaraches, which consist of used tire rubber wrapped to their feet.
How do Tarahumara run for hundreds of miles in such primitive footwear? To Nike-clad runners like myself, the answer was painfully simple: they just do it. Barefoot Tarahumara children build calluses and foot strength from an early age on the rocky, rugged canyon trails. They rarely get injured, thanks to their running lifestyle and efficient biomechanics.
Monday, February 23, 2009
Thursday, February 12, 2009
Three photographs of a male jaguar and exactly 132 poop samples (including the one above, released February 10) are the first known evidence of the predator since the early 1900s.
The big cat was snapped by a camera trap in the Sierra Nanchititla Natural Reserve.
Jaguars have disappeared from much of Mexico as humans have chopped up their habitat and sometimes killed the animals for the illegal wildlife trade.
Concerned that the big cat was locally extinct, an expedition team set out into the 260 square mile (674 square kilometer) reserve between 2002 and 2004.
The team talked to villagers within the study area, but no one had reported seeing the elusive animal.
That may be because the cats, which were photographed at 6,053 feet (1,845 meters), are forced by their diminishing habitat to travel across higher ground, said study leader Octavio Monroy-Vilchis of the Autonomous University of the State of Mexico.
Friday, August 1, 2008
The Standard Plan will receive final approval when three conditions are met:
A collection service plan that meets the rule requirements is completed
The Washington Materials Management & Financing Authority (Woodland) conducts at least one public hearing
The DOE determines that the WMMFA is meeting public outreach requirements.
Over 220 manufacturers of covered items have thus far registered with the electronics recycling program, with no proposals for independent plans being put forward, to date. Implementation of Washington's electronic recycling program is scheduled for January 1, 2009.
Monday, June 2, 2008
Do kids instinctively think logarithmically - and is this the smartest way to look at numbers after all?PunchstockI'd never have guessed, in the days when I used to paw through my grubby book of logarithms in maths classes, that I'd come to look back with fondness on these tables of cryptic decimals. In those days the most basic of electronic calculators was the size of a laptop and about as expensive in real terms, so books of logarithms were the quickest way to multiply large numbers (see 'What are logarithms'.
Of course, logarithms remain central to any advanced study of mathematics. But as they are no longer a practical arithmetic tool, one can’t now assume general familiarity with them. And so, countless popular science books contain potted guides to using exponential notation and interpreting logarithmic axes on graphs. Why do they need to do this? Because logarithmic scaling is the natural system for magnitudes of quantities in the sciences.
That's why a new claim that logarithmic mapping of numbers is the natural, intuitive scheme for humans rings true. Stanislas Dehaene of the Federative Institute of Research in Gif-sur-Yvette, France, and his co-workers report in Science 1 that both adults and children of an Amazonian tribe called the Mundurucu, who have had almost no exposure to the linear counting scale of the industrialized world, judge magnitudes on a logarithmic basis.
Down the line
The researchers presented their subjects with a computerized task in which they were asked to locate on a line the points that best signified the number of various stimuli (dots, sequences of tones or spoken words) in the ranges from 1 to 10 and from 10 to 100. One end of the line corresponded to 1, say, and the other to 10; where on this line should 6 sit? The results showed that the Amazonians had a clear tendency to apportion the divisions logarithmically, which means that successive numbers get progressively closer together as they get bigger.
The same behaviour has previously been seen in young children from the West2. But adults instead use a linear scaling, in which the distance between each number is the same irrespective of their magnitude. This could be because adults are taught that is how numbers are 'really' distributed, or it could be that some intrinsic aspect of brain development creates a greater predisposition to linear scaling as we mature. To distinguish between these possibilities, Dehaene and his colleagues tested an adult population that was 'uncontaminated' by schooling.
The implication of their finding, they say, is that "the concept of a linear number line seems to be a cultural invention that fails to develop in the absence of formal education". If this study were done in the nineteenth century (and aside from the computerized methodology, it could just as easily have been), we can feel pretty sure that it would have been accompanied by some patronizing comment about how 'primitive' people have failed to acquire the requisite mathematical sophistication.
Today's anthropology is more enlightened, and indeed Dehaene and his team have previously revealed the impressive subtlety of Mundurucu concepts of number and space, despite the culture having no words for numbers greater than five3,4.
Everything in perspective
But in any event, the proper conclusion is surely that it is our own intuitive sense of number that is somehow awry. The notion of a decreasing distance between numbers makes perfect sense once we think about that difference in proportionate terms: 1,001 is clearly more akin to 1,000 than 2 is to 1. We can even quantify those degrees of likeness. If we space numbers along a scale such that the distances between them reflect the proportion by which they increment the previous number, then the distance of a number n from 1 is given by the harmonic series, the sum of 1 + 1/2 + 1/3 + 1/4 and so on up to 1/n. This distance is roughly proportional to the logarithm of n.
This, it is often said, is why life seems to speed up as we get older: each passing year is a smaller proportion of our whole life. In perceptual terms, the clock ticks with an ever faster beat.
But wait, you might say – surely 'real' quantities are linear? A kilometre is a kilometre whether we have travelled 1 or 100 already, and it takes us the same time to traverse at constant speed. Well, yes and no. Many creatures, execute random walks or the curious punctuated random walks called Lévy flights, in which migrations over a fixed increment in distance takes an ever longer time. Besides, we can usually assume that an animal capable of covering 100 kilometres could manage 101, but not necessarily that one capable of 1 kilometre could manage 2 kilometres (try the latter case with a young child).
Yet the logarithmic character of nature goes deeper than that. For scientists, just about all magnitude scales are most meaningful when expressed logarithmically, a fact memorably demonstrated in the vision of the Universe depicted in the celebrated 1977 film Powers of Ten The femtometre (10-15 metres) is the scale of the atomic nucleus, the nanometre (10-9 metres) that of molecular systems, the micrometre (10-6 metres) the scale of the living cell, and so on. Cosmological eras demand logarithmically-fine time divisions as we move closer back towards the Big Bang. The immense variation in the size of earthquakes is tamed by the logarithmic magnitude scale, in which (roughly speaking) an increase of one degree of magnitude corresponds to a tenfold increase in energy. The same is true of the decibel scale for sound intensity, and the pH scale of acidity.
Law of the land
Indeed, the relationship between earthquake magnitude and frequency is one of the best known of the ubiquitous natural power laws, in which some quantity is proportional to the n th power of another. These relationships are best depicted with logarithmic scaling: on logarithmic axes, they look linear. Power laws have been discovered not only for landslides and solar flares but for many aspects of human culture: word-use frequency, say, or size-frequency relationships of wars, towns and website connections.
All these things could be understood much more readily if we could continue to use the logarithmic number scaling with which we are apparently endowed intuitively. So why do we devote so much energy to replacing it with linear scaling?
Linearity betrays an obsession with precision. That might incline us to expect an origin in engineering or surveying, but actually it isn't clear that this is true. The greater the number of units in a structure's dimension, the less that small errors matter: a temple intended to be 100 cubits long could probably accommodate 101 cubits, and in fact often did, because early surveying methods were far from perfect. And in any event, such dimensions were often determined by relative proportions rather than by absolute numbers. It seems more conceivable that a linear mentality stemmed from trade: if you're paying for 100 sheep, you don't want to be given 99, and the seller wants to make sure he doesn't give you 101. And if traders want to balance their books, these exact numbers matter.
Yet logarithmic thinking doesn't go away entirely. Dehaene and his colleagues show that it remains even in Westerners for very large numbers, and it is implicit in the skill of numerical approximation. Counting that uses a base system, such as our base 10, also demands a kind of logarithmic terminology: you need a new word or symbol only for successive powers of ten (as found both in ancient Egypt and China).
All in all, there are good arguments why an ability to think logarithmically is valuable. Does a conventional education perhaps suppress it more than it should?
Monday, January 21, 2008
Posted by Tom Philpott at 8:01 AM on 16 Jan 2008
Read more about: China United States toxics business consumerism climate greenhouse-gas emissions environmental justice
In the last 20 years, the United States has essentially dismantled its industrial base, moving production of consumer goods south to Mexico and east to Asia.
This has not only dramatically lowered the cost of goods, fueling a consumer boom; it has also helped make our economy less energy-intensive, and lowered our exposure to industrial waste.
But net gains for the environment and worker health have been imaginary. We've merely shifted the burdens of industrial production onto other lands and other people -- most recently, China.
Don't be a Cad.
I think this is the most important political-ecological story of our time -- made even more urgent by the specter of climate change (since for the climate, greenhouse-gas emissions from Huizhou, China, are just as damaging as those from Pittsburgh, Penn.). And I don't know of any other publication covering it with more rigor than the Wall Street Journal.
It has been running great articles on how U.S. demand for cheap goods is triggering a surge in consumption of Chinese coal. And on Tuesday, it ran a great piece on how U.S. industry responded to the well-documented hazards of cadmium-battery manufacturing by simply moving production to China, creating a nightmare for workers there.
Here is the Journal:
Once widely manufactured in the West, [cadmium] batteries are now largely made in China, where the industry is sickening workers and poisoning the soil and water.
Europe has banned most cadmium batteries. Not so the U.S., where they're "still widely used in toys, power tools, cordless phones and other gadgets." The article is worth reading in its entirety.
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