Category: Science
Build a house in 24 hours
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.
Do women look better when they are fertile?
Read this article.
Water on Mars
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.
The origins of human intelligence?
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.
Small families can decrease social mobility
…it is among larger families that the household or kin effects on the success of children are the weakest. Not only do children from larger families do worse on average than those from smaller families, but they also experience more randomness. In other words, parents’ class status affects their offspring more weakly in large families than in small ones. Likewise, siblings resemble one another less in larger families. For example, sibling similarity in income levels is approximately 24 percent stronger in families with three siblings or fewer than in families with four or more children. For net worth levels…the degree of sibling similarity is 59 percent greater in smaller families.
Those are significant effects, what will they mean?
What all this means for the class structure of American society is that as families get smaller, there may be less socioeconomic mobility, not more. Parents will be able to more carefully control the environments of their offspring and thereby reproduce their own class status.
There is a caveat:
Of course, this depends not just on the overall average number of kids that families are having, but also on the distribution. If the most dramatic declines in family size occur among the economically disadvantages segments of American society then we could have more equality of opportunity.
In other words, having larger families, across the board, will mean that subsequent income is less correlated with family history. But on average it will not raise the prospects of people from poor families.
From Dalton Conley’s excellent The Pecking Order: Which Siblings Succeed and Why. Follow this link and here for my earlier writings on Conley.
Born to Sue?
Frank Sulloway’s Born to Rebel (BTR) was a smash hit when it was published in 1996. Sulloway’s thesis, that laterborns are born to rebel while first-borns are conformist defenders of the status quo, was initially greeted with some skepticism among experts who knew of an earlier review of the large literature on birth order that had found little evidence for an effect on personality. The thesis struck a cord with the public, however, and Sulloway seemed to have gathered so much data from so many different sources (including scientific revolutions, political revolutions, religious revolutions etc.) that with a few exceptions (such as the great Judith Harris) the book won over skeptics and carried the day. Michael Shermer, Mr. Skepticism himself, said, for example, that Born to Rebel was “the most rigorously scientific work of history every written.”
Two devastating studies of BTR, however, have just now been published in the September 2000 issue of Politics and the Life Sciences (alas this issue is not online, perhaps for reasons discussed below). After exhaustive efforts, the studies failed to replicate key results in BTR – that is the authors tried to replicate what Sulloway said he did, on the data that he said he used and they could not reproduce anything close to his results. Now, you may be asking, how it is that the September 2000 issue of PLS has only now been published? And therein lies a story.
When Politics and the Life Sciences decided to publish the initial critique of BTR by Frederic Townsend, after peer review by four referees, it invited Sulloway to respond along with a number of others in a roundtable format that they had used in previous debates. Sulloway was guaranteed ample room to respond to Townsend and was invited to submit his own names for roundtable participants. He initially agreed but shortly thereafter he wrote to Gary Johnson, the editor of the journal, threatening that if the critique were published he would sue both the journal and the editor personally for what he considered to be defamation. Even if the Townsend article were thoroughly revised he insisted to the editor that it would be “appropriate – indeed legally mandatory – for you to preface his article with an editorial forewarning that reads more or less as follows”:
It is not normally the policy of this journal to publish data that are known, in advance, to be actually or potentially in error, especially when such data are being used in an attack on another scholar. However, as editor of this journal, I have decided…to publish these erroneous data in their present form. Readers are warned, however, that none of Townsend’s empirical claims, or the conclusions based upon them, can be trusted with any degree of certainty. Townsend has also made other blatant errors of fact and interpretation that are now known to the editor and that seriously affect the credibility of this paper….
Of course, the editor refused this absurd request. Sulloway later wrote to the president of the editor’s university (with copies to the chair of the Board of Trustees and the university’s legal counsel), saying:
…I intend to file charges of misconduct against one of your faculty members, Gary R. Johnson….these allegations include, but are not necessarily limited to: defamation/libel, false light invasion of privacy, fraud, promissory estoppel, and breach of fiduciary duty…I will also be blowing the whistle by filing formal charges of scientific misconduct against Gary Johnson with the American Political Science Association, the Human Behavior and Evolution Society, members of Congress who have shown a concern about science fraud, and all other professional organizations with which Professor Johnson or his journal….are affiliated.
Bear in mind that Johnson is only the editor of the journal and not even the primary critic! Naturally, Sulloway’s threats delayed publication of the journal, as more referees were involved and revisions took place, but the worst was yet to come. The journal’s publisher refused to publish the debate unless the parties involved committed not to sue him, his printer, his distributor, the journal, or the association. Of course, Sulloway refused. The heroic Johnson and the association then decided to publish the journal on their own. As a result, the final publication, including Sulloway’s response, is nearly five years late.
All of this, and there is much more that I have not reported, is from Johnson’s shocking editorial explaining the long delay. Perhaps the most disturbing aspect of the whole ordeal is that our legal system, sometimes described as Russian Roulette, has gotten sufficiently capricious and arbitrary that Sulloway’s abusive legal threats were nearly successful. Johnson writes:
The virtual terror that Sulloway’s legal threats have prompted in some of those associated – directly or indirectly – with the events described in this editorial suggests to me that contemporary science must adapt to a changed socio-legal environment if the capacity for open dialogue and critical exchange that is the lifeblood of science and scholarship is to be protected. Scholars, scientists, and publishers cannot focus properly on what should be their principal concerns if the threat of catastrophic legal costs hangs over them and their organizations and journals.
Smart prostitute with heart of gold
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?
What do we know about the children of gay parents?
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.
Are bubbles good for economic development?
Fools rush in, but should we mind?
…when it comes to transformative technologies, overoptimistic investors are actually working for the common good–even if they don’t know it. We can be glad that investors financed the construction of thousands of miles of track in the middle of the nineteenth century, despite the fact that most of them dropped a bundle doing it. The same goes for overoptimistic investors who poured money into semiconductors thirty years ago, financed undersea fibre-optic cables in the late nineties, and now are poised to lose their shirts in the coming nanobubble. In the dreams of avarice lie the hopes of progress.
The full story concerns the nanotechnology bubble, by the ever-intelligent James Surowiecki, writing for The New Yorker.
My take: The real story of the invisible hand is that many of the rewards offered by the capitalist system are illusory in value. Ayn Rand had a point that the world rests on the shoulders of the talented few. She forgot that those people often aren’t very rational.
Hot potatoes
I am delighted that I can now buy irradiated beef at my local supermarket. It’s safer than regular beef but I would buy it just to spite the anti-science hysterics who kept this technology off-the-shelf for decades. Irradiation has recently been approved for Hawaiian sweet potatoes – the expense of the previous technology, methyl bromide fumigation kept these purple spuds out of mainland markets.
Of course, the mainland-based U.S. Sweet Potato Council is worried about competition. Mainland growers produce 1.3 billion pounds annually and Hawaiian output is only 1.8 million pounds leading the Potato Council to a unique argument for protectionism, “Hawaiian production is a mere pittance . . . and therefore, Hawaii should be able to consume every sweet potato they produce and then some.”
Coin flips
Never bet on a coin flipped by mathematician and magician Persi Diaconis who can flip it so that it lands on heads at will. Diaconis has also shown, using high-speed slow motion cameras and plenty of physics, that when flipped by a regular person there is a 1-2 percent bias in favor of the side that begins up. Some more info here.
Over your lifetime this information ought be be worth quite a bit to you. Remember where you heard it first and act accordingly!
Maternal role models
…in families where the mother worked while her children were growing up, her adult daughters and sons attain jobs that are more equitable in terms of prestige. But in cases where the mother did not work – and therefore daughters lacked a direct, same-sex parental role model in the world of careers – sisters fare considerably worse than their brothers: my data show that women whose mothers did not work outside the home when they were growing up are 15 percent less likely to have graduated from college than their brothers were; this statistic stands in contrast to a statistically insignificant 5 percent difference between sisters and brothers in families where the mother did work outside the home for at least a year during their childhood. To put the impact of maternal employment in even starker terms, consider the following: if we hold education level and occupational prestige constant, sisters earn approximately less than $5,000 less in annual income than do their brothers. If we divide this same data according to maternal employment, however, the pattern diverges wildly. For those whose mothers worked outside the home when they were growing up, the income differential between sisters and brothers is reduced to approximately $4,5000 – but for those whose mothers did not work, the income differential shoots to more than $8,000.
From Dalton Conley’s excellent The Pecking Order: Which Siblings Succeed and Why. Here is my earlier post on Conley.
What is the bottom line here? If a mother works, her daughters are more likely to earn an income commensurate with their familial status. Working moms should feel less guilty.
Why celebrities are good for your kids
Celebrity worship may play an important part of growing up, suggest the results of a UK study.
Star-struck teens are generally emotionally well-adjusted and popular, with their celebrity interests forming a healthy part of adolescent development and bonding, say psychologists from the Universities of Leicester and Coventry.
However, those with extreme celebrity fascination, are likely to be lonely children without close attachments to friends or family, suggests the new study.
John Maltby and David Giles surveyed 191 English schoolchildren between the ages of 11 and 16. They found that those who avidly followed celebrities’ lives were the most popular.
For about 30 per cent of the children, gossiping about favourite celebrities with their peer group took up much of their social time. These children were found to have a particularly strong and close network of friends and to have created a healthy emotional distance from their parents.
“As children grow up, they start to transfer their attachment from parents to their peers. Celebrities start to take on the hero status role that their parents formerly fulfilled when the children were younger and it seems to be a healthy part of development,” explains Maltby, who led the study.
“The main function of celebrity attachments in adolescence may be as an extended social network – a group of ‘pseudo-friends’ who form the subject of peer gossip and discussion,” he told New Scientist. “The ongoing subject of celebrities’ lives can provide a valuable bonding tool among their friends, while enabling them to be emotionally autonomous from their parents.”
Here is the full story. And don’t forget my book on fame, which views the production of celebrity as one of the most beneficial aspects of modern popular culture. Not only do stars give us focal points for social orientation, but we gain by paying them with fame rather than having to part with more money.
Teens really are less motivated
Teen brains show less activity in the regions associated with motivation, reveals a brain imaging study.
And adolescents may be more willing to engage in dangerous activities such as drink [sic] driving because this crucial part of their brain is under-developed, the US researchers suggest…Perhaps teens seek more extreme behaviours to achieve normal levels of stimulation in this brain region, he suggests.
Here is a longer discussion. I know I will receive hundreds, maybe even thousands, of angry emails from parents who cannot possibly believe this is true. But the reporting of science must progress, what can I say?
P.S. The skeptical may wish to note that the sample size is twelve teenagers and twelve adults for the study. But alas, no motivated teen wrote to tell me that.
Addendum: Randall Parker adds much more.
Is the earth seeding space with life?
Perhaps microbes are riding on specks of dust.
A grain less than a tenth of a millimetre across would still be capable of carrying microscopic life, says Napier. And the pressure of sunlight can quickly blow grains this small out of the solar system. The same force might one day propel spacecraft through the cosmos.
Such a grain could travel about six light years from Earth in 70,000 years – far enough to reach other stars. We could be surrounded by a huge ‘biodisk’ of frozen organisms floating on grains of rock, says Napier, all of which can wander in and out of our solar system quite easily. “The solar system is as leaky as a sieve,” he says.
Earth should spread its seed widest when we pass through a giant molecular cloud, a mass of dusty material from which stars are born. This has happened about five times since life appeared on Earth.
Each time, Napier estimates about three billion trillion microbes passed from Earth into the cloud. The chances of some of these finding their way to an Earth-like planet are quite high, he says. A similar process could even explain how the Earth wound up hosting life in the first place, he adds.
Panspermia is one of my favorite words.