Category: Science

In a move unprecedented in the Bay Area, the city’s traffic engineers have created a traffic signal with attitude. It senses when a speeder is approaching and metes out swift punishment.

It doesn’t write a ticket. It immediately turns from green to yellow to red.

Here is the full story, thanks to the ever-vigilant Geekpress.com.

My take: This will succeed in reducing speeding. By making the decision calculus more uni-dimensional (time vs. time, rather than time vs. speeding ticket), individiuals are more likely to see the folly of driving at unsafe speeds.

Here is a general introduction to framing effects. Here is a short article about framing effects in Alice in Wonderland. Here is Daniel Davies on how framing effects matter.

But what about civil liberties? One commentator opined: “It’s depriving you of another one of your liberties — going fast”.

Addendum: Tim Worstall writes in:

“The anti speeder traffic light ?
Been around for years.
Here in Portugal they’re all over the place.
And they work very well, just as advertised.”

The highest suicide rate in the world has been reported among young women in South India by a new study. The research is of major importance, according to the World Health Organization, as it brings to light Asia’s suicide problem.

The average suicide rate for young women aged between 15 to 19 living around Vellore in Tamil Nadu was 148 per 100,000. This compares to just 2.1 suicides per 100,000 in the same group in the UK.

The global suicide rate stands at 14.5 deaths per 100,000, with suicide the fourth leading cause of death in the 15 to 19 age group. However, in the Tamil Nadu study, suicide was the number one cause of death among these adolescents.

Notably, young women were much more likely to kill themselves than young men – the reverse of the rest of the world. In Western countries, men are three times more likely to commit suicide than women.

Here is the full story. Here is an NBER paper on the determinants of teenage suicide in the United States. Earlier Alex wrote about suicide as a social phenomena involving tipping and multiple equilibria.

Freeman Dyson introduces us to Littlewood’s Law of Miracles:

Littlewood was a famous mathematician who was teaching at Cambridge University when I was a student. Being a professional mathematician, he defined miracles precisely before stating his law about them. He defined a miracle as an event that has special significance when it occurs, but occurs with a probability of one in a million. This definition agrees with our common-sense understanding of the word “miracle.”

Littlewood’s Law of Miracles states that in the course of any normal person’s life, miracles happen at a rate of roughly one per month. The proof of the law is simple. During the time that we are awake and actively engaged in living our lives, roughly for eight hours each day, we see and hear things happening at a rate of about one per second. So the total number of events that happen to us is about thirty thousand per day, or about a million per month. With few exceptions, these events are not miracles because they are insignificant. The chance of a miracle is about one per million events. Therefore we should expect about one miracle to happen, on the average, every month. Broch [co-author of the book Dyson is reviewing] tells stories of some amazing coincidences that happened to him and his friends, all of them easily explained as consequences of Littlewood’s Law.

The law echoes a comment I’ve seen attributed to another mathematician, Persi Diaconis. Diaconis supposedly said that if you study a large enough population over a long enough time period, then “any damn thing can happen.”

Washington is preparing for an invasion. Several weeks from now billions and billions of insects will ascend upon the city from their hiding places under the ground to be begin two weeks or so of frenzied sex followed by egg-laying and dying. I know what your thinking – there goes Tabarrok again with his apocalyptic visions of doom and gloom.

The invaders, however, are not the biblical locusts of old but cicadas and they are going to be sex-starved because they only do this every 17 years. Why 17? No one knows for sure but 17 is prime so to meet the cicadas every time they appear a predator must lock-on to the exact frequency (while if they appeared say every 12 years then predators appearing every 2,3,4,6, or 12 years would be sure to meet them). There is another variant of periodical cicada that appears every 13 years, supporting the prime theory.

The cicadas are loud and the WashPost notes that the 1970 appearance of brood X inspired Bob Dylan to pen these lines:

And the locusts sang, well, it give me a chill,

Yeah, the locusts sang such a sweet melody.

And the locusts sang with a high whinin’ trill,

Yeah, the locusts sang and they was singing for me . . .

Addendum: Thanks to Marc Poitras for correcting me on one point. The cicadas can get plenty to eat underground so they really are coming out for the sex. Makes sense to me.

In their paper titled “Love’s Labour Lost,” recently submitted to a medical journal, anthropologist Edward Hagen, biologist Paul Watson and psychiatrist Andy Thomson suggest that full-blown major depression disorder may be a complex social adaptation originating in the human evolutionary past and designed to help otherwise powerless individuals influence their social groups, focus on problem-solving and obtain help from those with whom one is in conflict.

“Depression evolved to compel assistance from reluctant social partners,” they theorize. “Depression signals need and compels social assistance by preventing the sufferer from providing benefits to others.”

They cite the severe cost of depression not only to the individual but to the whole social network.

“The toll depression takes on both its victims and society may be precisely what it was, in human evolutionary history, designed to do.”

This thinking – that depression is an important signal and part of a complex dynamic among people that provokes change – leads these researchers to argue that drug therapy alone for depression may not be the best solution even it relieves symptoms.

It may be that non-chronic major depressive disorder (MDD) is like fever – a signal that something has gone awry and needs to be healed.

Here is the full story. Here is a link to the relevant research. Here is the specific piece in question. Here is a related piece, called “Depression as Bargaining”. For a good time try using that description on your girlfriend.

Why I am skeptical: I can see why emotional sensitivity to bad events has survival value. Emotions bring general benefits, plus the sensitivity keeps you away from bad events to some degree. It is harder for me to see a great importance for the negative reaction itself, ex post, once bad events have happened.

Randall Parker cites the following link:

Degussa AG, one of the world’s largest manufacturers and suppliers of construction materials, will collaborate in the development of a USC computer-controlled system designed to automatically “print out” full-size houses in hours.

Funded by a grant from the National Science Foundation, Behrokh Khoshnevis of the USC Viterbi School of Engineering’s Information Sciences Institute has been developing his automated house-building process, called “Contour Crafting,” for more than a year.

Khoshnevis believes his system will be able to construct a full-size, 2,000- square-foot house with utilities embedded in 24 hours. He now has a working machine that can build full-scale walls and is hoping to actually construct his first house in early 2005.

Contour Crafting uses crane- or gantry-mounted nozzles, from which building material – concrete, in the prototype now operating in his laboratory – comes out at a constant rate.

Moveable trowels surrounding the nozzle mold the concrete into the desired shape, as the nozzle moves over the work.

Parker adds:

Robots and other automated equipment have increased factory automation so much that factories are a dwinding source of all jobs. The next big target for automation has been and continues to be office work. Office automation is being addressed with the development of huge amounts of software and information systems.

What never seem to get as much attention is how to automate all the other places where people work aside from the office and the factory. Construction automation is an obvious big target. One approach is to do prefabrication of walls and other building pieces in highly automated factories. Then the prefabricated parts can be shipped to the construction site. But automated methods to doing construction at a site have advantages because they avoid the difficulty of shipping large walls, floors, and ceilings to a site. Also, automated site construction techniques allow more flexibility in site design.

My take: In economics language, this is called “g>r”, which refers to the growth rate of an economy exceeding its rate of interest. If we’re going to make it through our forthcoming fiscal crises, it will be through innovations such as these.

Read this article.

Maybe there was once water on Mars. Maybe not. Reuters reports:

“We think Opportunity is now parked on what was once the shoreline of a salty sea on Mars,” said Steve Squyres, principal investigator for the science payload on Opportunity and its twin Mars exploration Rover, Spirit.

On March 2, astronomers announced that the Red Planet was “drenched with water” at some point. But the rovers’ analysis of Mars rocks has now produced the first concrete evidence that liquid water might actually have flowed on planet’s surface.

“If you have an interest in searching for fossils on Mars, this is the first place to go,” said Ed Weiler, NASA’s associate administrator for space science.

Love that alliteration–the shoreline of a salty sea. It conjures up images of beachcombers and cottages or at least seashells and seaweed with terns turning in the sunlight. Seems like a bit of a stretch. NASA thinks they’ve found not just moisture, not just a few molecules of H2O but a sea with rocks drenched with salty spray, rocks lovingly shaped by streaming water. Pardon my skepticism, but it seems that NASA has just a bit of interest in stretching the results. Notice that even Reuters uses the word “might.”

This hasn’t dampened any of the enthusiasm. Here’s one analysis headlined “Mars water discoveries loom huge” that compares the finding to Galileo’s discoveries.

…the sheer disclosure of the presence of water on a planet other than our own is monumental. It ranks with the moment, nearly 400 years ago, when Galileo Galilei peered through his telescope and discovered spots on the sun, mountains on the moon and four tiny bodies circling Jupiter.

Those revelations, which today are taken for granted, also were monumental in their day. Prior to their disclosure, people confidently — even fervently — believed Earth was the immovable center of the universe, surrounded by all the heavenly bodies, each of which was a perfect, featureless sphere. Galileo’s announcement was considered so shocking at the time he was charged with heresy by the Roman Catholic Church.

Opportunity’s findings have been treated more matter of factly, with NASA officials holding a news conference and bubbling over with enthusiasm at the images Opportunity has transmitted, and members of the media duly reporting the information and displaying the rover’s images.

Yet the importance of this finding cannot be overstated.

Until now, we have known for sure of only one planet on which liquid water has flowed — and water is absolutely essential for supporting life as we know it. There are no chemical processes that will permit the formation of the long, complex organic molecules composing living organisms other than in the presence of water.

It is an extremely simple rule: No water, no life. As long as Earth was the only planetary body containing liquid water — and, more particularly, seawater — then it was the only place in the universe where life was possible.

Now, suddenly, there are two.

Is this a huge discovery? Huge for NASA, certainly, eager to send people to Mars in search of fossils or at least an abandoned sailboat.

I’m in the middle of Simon Morris’s Life’s Solutions: Inevitable Humans in a Lonely Universe. I suspect Morris is unimpressed with the latest Martian chronicle. He argues that it is very likely that we’re alone in the universe. The first part of the book that makes this claim is fascinating with quirky writing and lots of good information. The rest of the book argues for the inevitability of humanity evolving. The writing and narrative of the second half is less spritely and slower going but the first part of the book is very much worth a look.

Researchers have proposed an answer to the vexing question of how the human brain grew so big. We may owe our superior intelligence to weak jaw muscles, they suggest.

A mutation 2.4 million years ago could have left us unable to produce one of the main proteins in primate jaw muscles, the team reports in this week’s Nature. Lacking the constraints of a bulky chewing apparatus, the human skull may have been free to grow, the researchers say.

The timing of the mutation is consistent with rampant brain growth seen in human fossils from around 2 million years ago, says Nancy Minugh-Purvis of the University of Pennsylvania in Philadelphia, who helped with the study. “Right at the point you lose power in these muscles, brain size evolution accelerates,” she says.

Here is the full story. Here is the original research. Here is another account, which also reports on the critics of the idea. My gut level lay person’s response is not to believe the hypothesis, but hey, try convincing a physicist of the notion of comparative advantage.

Earlier Tyler reported that lying is more common over the phone than with email. Further evidence comes from a surprising source. In a letter to New Scientist magazine Yvette Astre writes:

I have found a similar difference between phones and email in my business.

I am a prostitute, and to get clients I advertise in the local newspaper. Normal practice is to provide a phone number as an initial point of contact. Using my cellphone was getting rather expensive, as was advertising several days a week. I also work as a volunteer for several non-profit community organisations, and there I found many people preferred emails to the phone or postal services. So I decided to try an email address instead.

The difference really surprised me. With my phone number, guys would sometimes make bookings then not turn up. Others sounded very creepy. However, using email I have had only two cancellations, and in both cases I was paid in full for the time they booked with me.

Then again, prostitutes who read New Scientist and volunteer at non-profits? Johns who pay for services not rendered? Was this letter phoned in or emailed?

Not much, according to this incisive article on Slate.com: “The existing science is methodologically flawed and ideologically skewed.”

Here is another major point:

…the defensive goal of proving sameness is almost a guarantee of weak science. (The hypothesis that both groups of kids are alike is hard to rule out, but that doesn’t mean you’ve established that there are no differences.) That “heterosexist” bias, Stacey argues, has also encouraged researchers to fudge results, anxiously claiming homogeneity where there’s actually some variety. Why, she asks, buy into the view that “differences indicate deficits”?

And consider the following:

Digging around in the existing data on kids of gay parents leads the authors and others to similarly rosy speculations that these children are unusually open-minded. Some studies, for example, show boys playing less aggressively and behaving more “chastely” as youths, while girls’ early interests are more androgynous and their adolescence evidently somewhat more sexually adventurous. On the hot topic of sexual orientation, the only long-term study of lesbian-headed families reports 64 percent of the young adult children saying they’ve considered same-sex relationships (compared to 17 percent with heterosexual parents)–although the percentage of those who identify themselves as gay, lesbian, or bisexual is the same in both groups.

Here is a survey of some reader reactions.

The bottom line: We need some good labor economists, or demographers, to tackle this problem. That being said, the policy-relevant comparison is not “gay parents” vs. “straight parents.” Rather it is gay parents vs. an orphanage, or gay parents vs. not having been born in the first place. I’ll put my money on the gay parents.