Category: Science

How Colombia solves its traffic problems

Drive as fast as possible. Be aggressive too:

Traffic experts had previously been puzzled as to how Bogotá, with 7 million inhabitants and more than a million private cars, is so jam-free. The answer now seems that Bogotáns are simply more aggressive than their counterparts in London, New York and other huge metropolises.

But why the dare-devil style? Olmos and Muñoz point out that, before improvements to Bogotá’s public-transport and cycling infrastructure, and restrictions on the use of private cars, the city was routinely gridlocked. Perhaps formerly frustrated motorists are now revelling in the open road.

Still, freedom comes at a price, say the researchers: one in six Colombians who die a violent death meet their end in a traffic accident.

I’ve long suspected that something like this would prove true. If you can’t afford to synchronize your lights, just let drivers run them at will. The results also may explain why traffic in Mexico City flows at all.

Here is the original research. Here is an earlier MR post on Colombia.

The next killer app, or who needs books?

The picture definition on Japanese camera-phones is now so high that people can stand in a shop, surreptitiously photograph the pages of a magazine and then later read their ill-gotten literature from the screens of their mobile phones.
Japan’s booksellers have risen as one to demand that the Government criminalises this practice…
…the thefts have become more ambitious. Students, for example, are finding that entire textbooks can be photographed and read later at palm-sized convenience.
The publishing industry is suffering badly from the advance of mobile phones in Japan. Where once the train carriages were full of people reading comics or newspapers, passengers now concentrate solely on the screens of their phones. Mobile phone operators say that text-message volumes correspond almost exactly with the commuter rush-hour peaks and troughs.
The latest phones come equipped with a tuner that can — fuzzily — pick up television broadcasts, and several operators have introduced phones with navigation software that shows the user as a moving red blip on an ultra-detailed street atlas of Japan.

That’s from The Times, June 5, 2004, p.2W, no link available. Here is some background information. Here is a related article. Here is a more general article on the illegal downloading of books.

To be continued…

Sand dreams and spontaneous order

One of my dreams is to go to Niger. In the meantime I will have to be satisfied reading the excellent Sahara: A Natural History, by Marq de Villiers and Sheila Hirtle. No student of spontaneous orders can ignore the following passage:

Obviously [sic], dunes are formed because jumping sand bounces more easily off hard surfaces than off soft ones, so that more sand can be moved over a pebbly desert surface than over a smooth or soft one. Even a slight hollow, though, or a rock, will reduce the amount of sand that the wind can carry, and a small sand patch begins. Very quickly, this patch will trap more sand. When the patch is big enough, it begins to change the wind velocity about it. The winds decrease near the surface and deposit more sand on the patch. Quickly, the dune is built up.

If the conditions are right, the dune will grow rapidly: In days it will be taller than a man, and in just a few weeksit can reach sixty-five or one hundred feet, and keep growing. Over time, the windward slope eventually adjusts itself, and the wind velocity close to the sand increases to compensate for the drag imposed by the sandy surface. The smooth leeward slope steepens until the wind can’t be deflected down sharply enough to follow it, leaving a “dead zone” into which the sand falls. When this so-called dispositional slope reaches the natural slope angel of dry sand (about thirty-two degrees), the added sand cascades down the slope, now called the “slip face.” The dune has stopped growing — there is no gain or loss of sand — though it continues to move forward as a whole, slowly, ponderously, relentlessly.

It turns out that driving on sand is an art, and no one can avoid getting stuck in the long run. Fortunately (to my surprise) most of the surface of the Sahara is rock rather than sand.

Here is a lecture on spontaneous order and sand. Here is advice on how to build a better sand castle.

Every now and then someone is inclined to think that this kind of analysis holds the key to either business cycles or stock market crashes. It has yet to come through, but in the meantime I will keep dreaming of Niger.

An argument for genetic engineering

Soon we will have cows that are immune to mad cow disease. We’re not about to engineer cows on a large scale, and probably we don’t need to; my interest is in how this upsets the usual spectrum of ecological worries. I’ve found that people who fear mad cow disease also tend to fear genetic engineering of animals. But now, which way to turn? It reminds me of those reports saying we need not fear global warming, because we will run out of oil in the meantime!

Beauty and Brains

Last week, Alex wrote about how smart people live longer. Today, we learn that smart people may be better looking too!

Satoshi Kanazawa of the London School of Economics and his colleague, Jody L. Kovar, assert that beautiful people also tend to be smart people — and vice versa.

In the July issue of Intelligence, the sociologists offer a theory to explain the confluence of beauty and brains. Their argument, in a nutshell: Intelligent men achieve higher status and marry beautiful women, who pass their genes on to their disproportionately attractive and smart kids, who win mates who are good-looking or brainy, and so on. Or at least that’s what they put forth in the journal article, “Why Beautiful People are More Intelligent.”

Here is the full story. Here is a home page for one of the researchers. But wait…he’s the same guy who says that marriage ruins male productivity.

Addendum: I just stumbled upon Randall Parker’s treatment of the same study.

The largest known prime number

We just found a new one, and it has seven million digits. Here is the bottom line:

Mersenne primes are an especially rare type that take the form 2^p-1, where p is also a prime number. They are named after a 17th Century French monk who first came up with an important conjecture about which values of p would yield a prime. The new number can be represented as 2^(24,036,583)-1. It is the 41st Mersenne prime to have been found.

Here is the full story.

Note also that the number was found by a consortium of private computers, designed to exchange spare computing power:

GIMPS volunteers download a piece of software that runs in the background on their computer. A central server distributes different prime number candidates to each machine, which use spare processing power to test whether it is a genuine prime or not.

Here is more information, plus how to volunteer. Or perhaps you would prefer to search for alien lifeforms.

Smart people live longer

Earlier I discussed the evidence from Oscar winners that higher status leads to better health. Steve Sailer alerts me to a good article from Forbes challenging the status explanation in favor of an effect of IQ on health.

Why is it that, all around the world, those with more income, education and high-status jobs score higher on various measures of health? ….The traditional answer to these questions has been that greater wealth and social status mean greater access to medical care. But even ten years ago, when this magazine last delved into the topic (FORBES, Jan. 31, 1994), the available answers seemed inadequate. If access was the key, then one would have expected the health gap between upper and lower classes to shrink or disappear with the advent of programs like Britain’s National Health Service and America’s Medicare and Medicaid, not to mention employer-sponsored health insurance. In fact, the gap widened in both Britain and America as these programs took effect. The 1994 article cited a study of British civil servants–all with equal access to medical care and other social services, and all working in similar physical environments–showing that even within this homogeneous group the higher-status employees were healthier: “Each civil service rank outlived the one immediately below.” How could this be?

Today the standard answer–or, at least, the answer you are guaranteed to get from the WHO and other large health bureaucracies–is that inequality itself is the killer. …

[But a new theory has been put forward by] Linda Gottfredson, a sociologist based at the University of Delaware, and psychologist Ian Deary of the University of Edinburgh. Their solution to the age-old mystery of health and status is at once utterly original and supremely obvious. The rich live longer, they write, mainly because the rich are smarter. The argument rests on several different propositions, all well documented. The crucial points are that (a) social status correlates strongly and positively with IQ and other measures of intelligence;(b) intelligence correlates strongly with “health literacy,” the ability to understand and follow a prescription for disease prevention and treatment; and (c) intelligence is also correlated with forward planning–which means avoidance of health risks (including smoking) as they are identified.

The first leg of that argument has been established for many decades. In modern developed countries IQ correlates about 0.5 with measures of income and social status–a figure telling us that IQ is not everything but also making plain that it powerfully influences where people end up in life. The mean IQ of Americans in the Census Bureau’s “professional and technical” category is 111. The mean for unskilled laborers is 89. An American whose IQ is in the range between 76 and 90 (i.e., well below average) is eight times as likely to be living in poverty as someone whose IQ is over 125.

Second leg: Intelligent people tend to be the most knowledgeable about health-related issues. Health literacy matters more than it used to. In the past big gains in health and longevity were associated with improvements in public sanitation, immunization and other initiatives not requiring decisions by ordinary citizens. But today the major threats to health are chronic diseases–which, inescapably, require patients to participate in the treatment, which means in turn that they need to understand what’s going on….

Deary was coauthor of a 2003 study in which childhood IQs in Scotland were related to adult health outcomes. A central finding: Mortality rates were 17% higher for each 15-point falloff in IQ. One reason for the failure of broad-based access to reduce the health gap is that low-IQ patients use their access inefficiently. A Gottfredson paper in the January 2004 issue of the Journal of Personality & Social Psychology cites a 1993 study indicating that more than half of the 1.8 billion prescriptions issued annually in the U.S. are taken incorrectly. The same study reported that 10% of all hospitalizations resulted from patients’ inability to manage their drug therapy. A 1998 study reported that almost 30% of patients were taking medications in ways that seriously threatened their health. Noncompliance with doctors’ orders is demonstrably rampant in low-income clinics, reaching 60% in one cited s tudy. Noncompliance is often taken to signify a lack of patient motivation, but it often clearly reflects a simple failure to understand directions.

Although I doubt that IQ explains the longevity of Oscar winners relative to nominees I think it does explain a great deal – indeed, it would be astonishing if IQ didn’t impact health. By the way, I recommend Deary’s Intelligence: A Very Short Introduction and here is an even shorter introduction.

Bigger than you think

The universe, that is. New estimates for its size, based on measured microwave radiation, are up to 78 billion light years. And that’s a minimum. The bad news? Given this size, it is less likely that light can “wrap around” an odd-shaped universe, allowing us to see what the earth looked like four billion years ago. And here’s more evidence that the universe is dominated by “dark energy,” causing it to expand, possibly forever.

How to maximize the return from caffeine (and other stimulants)

Take small sips, and spread them out across the day. Don’t start your morning with too much coffee, yeah that means you too. Here is the full analysis, from the ever-insightful Randall Parker. This result reminds me slightly of the Barro-Gordon model of monetary policy. Don’t take your inflation all at once. If you haven’t had some inflation in a while, a mild dose of inflation can provide a nice stimulus.

IQ hoax

A table purporting to show IQ by state swept through the blogosphere last week mostly because liberal bloggers enjoyed trumpeting the high correlation it showed between high-IQ and voting for Gore in 2000. Turns out that the table was a hoax. Steve Sailer has the whole story including some real data on education by state and IQ by nation.

Do dogs resemble their owners?

Yes, but only if the dogs are purebreds.

The researchers photographed 45 dogs and their owners at three dog parks and gathered information about the breeds and how long owners and pets had been together. They then asked 28 students to try to match the people to the pooches.

The students were able to match dogs to their owners, but only when the dogs were purebred.

“The results suggest that when people pick a pet, they seek one that, at some level, resembles them, and when they get a purebred, they get what they want,” the researchers wrote. “A nonpurebred puppy’s final appearance is unpredictable, and so the resemblance . . . should be confined to the much more predictable purebreds.”

There was no relationship between how long owners had lived with their dogs and the chance that their appearances would match.

“These results were consistent with the notion that the ability to match is due to selection rather than convergence,” they wrote. “However, it does appear that, as in the case of selecting a spouse, people want a creature like themselves.”

Here is more statistical information.

Not surprisingly, many commentators believe that we select Presidents on the same basis.

Mind over Muscle or Where is Fatigue?

The old theory, taught to me in high school, is that muscles become fatigued when they run out of fuel/oxygen or they become suffused with lactic acid, an unpleasant byproduct of work. But if this is so, why do athletes almost always manage to go their fastest in the last mile of a race when their muscles should be closest to exhaustion? An article in New Scientist, (“Running on Empty,” by Rick Lovett, 20 March, 04, p.42-45, a copy is here) based on the work of Timothy Noakes and others, raises some more puzzles and offers a new theory.

If fatigue is based in the muscles then without more fuel, oxygen or less lactic acid you should not be able to improve performance. Yet, amphetamines and drugs like Ecstasy do allow athletes and clubbers to work and play harder (sometimes to dangerous effect). Measurements of the input factors also show that (absent unusual factors) fatigued muscles don’t in fact run out of critical factors.

The common sense response to these puzzles is that runners speed up in the last mile because they know it is the last mile and are willing to push themselves to their limits. Similarly, drugs fool the brain into thinking that the muscles are less fatigued than they are. If one thinks seriously about this common sense notion, as has Thomas Noakes, it provides a quite different view of fatigue than the old theory. The brain in this view is a central regulator that monitors the muscles and sends out messages of fatigue, quite possibly long before the muscles are truly spent as a sort of insurance policy. The central regulator theory doesn’t say that fuel and oxygen are unimportant only that the relation between fuel and fatigue is mediated by the brain.

The central regulator may have rational expectations. Experienced runners apparently report that the first mile of a 10k race is easier than the first mile of a 5k race. Makes no sense on the old theory but if you think about the central regulator meting out a fatigue budget in advance then everything becomes clear.

How then to improve performance? Try convincing yourself that you are running a 10k instead of a 5k (hypnosis may work). Also, Noakes suggests interval training, interspersed bouts of high intensity workouts with recovery breaks. The idea here is to the teach the central regulator that going faster won’t do you any harm.

If you can’t slow down time, try this…

Control your pain through biofeedback:

People can learn to suppress pain when they are shown the activity of a pain-control region of their brain, a small new study suggests. The new biofeedback technique might also turn out to be useful for treating other conditions.

Biofeedback techniques based on electroencephalogram (EEG) recordings of brainwave patterns, in which electrodes are placed on the scalp, are used with some success to treat epilepsy and attention problems such as ADHD.

…Fumiko Maeda, Christopher deCharms and their colleagues at Stanford University in California have tried showing people real-time feedback from a functional magnetic resonance imaging (fMRI) scanner.

The eight volunteers saw the activity of a pain-control region called the rostral anterior cingulate cortex represented on a screen either as a flame that varied in size, or as a simple scrolling bar graph. This brain region is known to modulate both the intensity and the emotional impact of pain.

During the scans the volunteers had to endure painful heat on the palm of their hand. They were asked to try to increase or decrease the signal from the brain scanner and to periodically rate their pain sensations.

It took just three 13-minute sessions in the scanner for the eight volunteers to learn to vary the brain activity level, and thus to develop some control over their pain sensations, the researchers reported at the Cognitive Neuroscience Society meeting in San Francisco last week.

Interestingly, none of the participants could explain how they managed some control. But it seemed to work, albeit on a small number sample.

Why stop here? Why not carry around an advanced biofeedback monitor and console to control your emotions more generally?

The bottom line: I can’t imagine how welfare economics will look two hundred years from now.