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China pledged to prevent rain during this year's Olympics. Methods: 1) Inject clouds with chemicals that increase droplet size and flush out rain before clouds reach the stadium. 2) Inject chemicals that shrink droplets so the rain doesn't fall till clouds have passed the stadium. Delivery systems: 7,000 anti-aircraft guns, 4,000 rocket launchers, and 30 aircraft that can fire the chemicals. Supervising agency: The "bureau of weather modification." Critique: Weather modification doesn't work. Chinese rebuttals: 1) We've used it for decades to alleviate droughts. 2) We've validated current methods experimentally. 3) Weather modification can't stop heavy rain, but it can mitigate light rain. (Human Nature's view: Why should Americans resort to cloud-seeding when we can already control rainfall through prayer?)
Social scientists are debating whether the housing boom has caused a baby boom. Data: 1) The fertility rate in 2006 reached replacement level (2.1 kids per woman) for the first time in 35 years. 2) This followed record rates of home-buying. 3) In previous times when homes were scarce or too expensive, fertility rates declined. 4) In countries where homes are scare or too expensive, fertility rates decline. Theories: 1) The house gives you space to expand your family. 2) The house is so far out of the city that you bag the commute, stay home, and raise kids. Alternative theories: Fertility rates are more responsive to income, immigration, religion, and confidence in the economy. Upside of the fertility surge: Today's babies will help pay for the boomers' retirement. Downside: Today's babies will become the new boomers. (Related: 1) Bigger houses let more couples sleep apart. 2) Giving workers a day off to have sex and make babies.)
Three studies suggest marijuana may be more harmful than tobacco. Study #1: "Smoking a joint is equivalent to 20 cigarettes in terms of lung cancer risk." Reasons: Joint smoke has "twice the level of carcinogens"; joints "are typically smoked without a proper filter and almost to the very tip"; and "the cannabis smoker inhales more deeply and for longer." Study #2: "Pot smokers may experience pathological changes in their lungs decades earlier than such changes usually occur in cigarette smokers." (The gap is 20 years.) Study #3: "Withdrawal from the use of marijuana is similar to what is experienced by people when they quit smoking cigarettes," including "irritability, anger and trouble sleeping." Critique: The three studies covered only 100 people altogether, and none was representative. (Related: Is tobacco really worse than pot?)
Vending machines are dispensing marijuana in Los Angeles. Cost: $40 per eighth of an ounce. Rationale: Pain relief and other medicinal purposes. Requirements: You have to 1) be registered in a database of medically approved users, 2) submit a fingerprint to prove your identity, and 3) insert a prepaid card. Buzzword: "Prescription Vending Machine." Supporters' arguments: 1) The pot relieves pain. 2) Machine dispensing is convenient. 3) It's private, to help you get past your embarrassment at buying pot. 4) By eliminating human dispensers, it reduces costs. 5) By eliminating human dispensers, it reduces pot theft. 6) By eliminating human dispensers, it reduces the number of people busted when the feds raid the dispensary, since the feds treat medical marijuana like any other illegal drug. DEA reaction: We'll bust whoever stocks the machine. Connoisseurs' critique: Some users prefer "to see and smell the drug before they buy it." (Related: Genetically altering pot to defeat drug enforcement.)
Investigators are unraveling India's biggest known ring of organ thieves and sellers. Participants: 30 to 50 doctors, nurses, paramedics, and clinic and hospital workers. Merchandise sold: 400 to 500 kidneys. Methods: 1) "Kidney scouts" looked for susceptible laborers. 2) Foreign clients were kept in a "luxury guesthouse." 3) Mobile equipment was used to test targets for biological matches to the clients. 4) Some targets were offered $1,000 to $2,500 for kidneys that were later sold at a 900 percent markup. 5) Other targets were deceived, kidnapped, blood-tested, knocked out with injections, and robbed of their kidneys. 6) Critics suspect hospitals and cops were in on it. Previous scandal: Organs purchased from Indians impoverished by the 2004 tsunami. (Related: Human Nature's take on the worldwide market in human organs.)
A big study suggests that exercise significantly slows aging. Previously known effects: Exercise prevents heart disease, diabetes, and cancer. New finding: It also slows the shortening of telomeres, which mark biological (not necessarily chronological) age. Data: 1) Counting by telomeres, moderate exercisers were 4 to 6 years younger than non-exercisers. 2) Heavy exercisers were 9 years younger. 3) Even among twins (who share genes and birthdays), heavy exercisers were 4 years younger. Theories: 1) Exercise reduces "oxidative stress" on cells. 2) It reduces inflammation. 3) It reduces psychological stress. Critiques: 1) Biological susceptibility to faster aging may cause lack of exercise, instead of the other way around. 2) Or the two variables may be joint products of some other factor. Rebuttal: The study ruled out such alternate factors. Old futuristic advice: Take these pills, and you'll live 10 years longer. New old-fashioned advice: Stop relying on pills, and get off your duff.
An Italian court rejected a law that restricts in vitro fertilization and genetic testing of embryos. The law bans such testing, prohibits creation of more than three embryos per cycle, and requires all created embryos to be implanted. Ruling: 1) The test ban is an "abuse of power." 2) The three-embryo limit violates the woman's rights if multiple pregnancies (which might be required because the limit lowers the odds of an embryo surviving to term) pose a risk to her health. Liberal reactions: 1) It's a victory for women's rights. 2) It's good for embryos, since they'll be tested for health. 3) Now couples can try for kids instead of holding back in fear of genetic disease. 4) Now couples can do IVF and testing in Italy instead of circumventing the law by leaving the country. Conservative reactions: 1) The test doesn't protect embryos with disease genes; it marks them for killing. 2) The ruling legitimizes eugenics. (Related: Take this embryo and shove it.)
A study suggests extreme happiness may be bad for you. Findings: 1) "The highest levels of income, education and political participation were reported not by the most satisfied individuals, but by moderately satisfied individuals." 2) Extremely happy people "earned significantly less money" and earned lower school grades than moderately happy people. 3) They "may not live as long," either. Theories: 1) Happiness makes you complacent and kills your drive. 2) It makes you slow to adapt. 3) It makes you too optimistic and insufficiently vigilant about your health. 4) It may overstimulate your cardiovascular system. Researchers' conclusions: 1) "Happiness may need to be moderated for success." 2) "Extremely high levels of happiness might not be a desirable goal." Human Nature's conclusions: 1) Success may need to be moderated for happiness. 2) Extremely high levels of success might not be a desirable goal.
Companies are genetically engineering crops to endure global warming. Problem: Warming means more heat and drought. Solution: Breeding and genetic engineering. Result: Crops that 1) have roots long enough to get more water from the ground, 2) conserve water more efficiently in stalks and leaves, and 3) direct more water to grow grain than to grow leaves. Objections: 1) This could pose unknown health risks. 2) It could worsen the environment. 3) Nature knows better than we do. Rebuttals: 1) You're already eating biotech crops. 2) They can help the environment by cutting water use. 3) They can grow enough food to prevent starvation on a warmed planet. (Related: HN's previous update on global warming and genetic engineering.)
Doctors are learning to assist transplants by helping donor cells take over parts of the recipient's body. Case study: A liver transplant 1) changed a girl's blood type to that of her dead donor and 2) changed most of her immune system to match her donor. Technical term for this human merger: chimerism. Gut reaction: It's a freaky invasion. Educated reactions: 1) It's no freakier than a marrow transplant. 2) It eliminates the usual problem of transplant rejection, since your body treats the new organ as yours. 3) Now let's figure out how to replicate this bizarre case. Related: 1) Doctors proved they can cause temporary chimerism by partially destroying your marrow and substituting the donor's marrow along with his kidney. 2) Blood-cell transplants can lead to chimerism, but not reliably. 3) The goal is to make the chimerism permanent. (Also related: DNA tests suggest "50 to 70 percent of healthy people are chimeras.")
Latest Human Nature columns: 1) Bush, stem cells, and stubbornness. 2) Abortion and teen sex. 3) Why the polls botched New Hampshire. 4) The best Human Nature stories of 2007. 5) The top privacy threats of 2007. 6) Are cultural trends changing our genes? 7) The travesty of political robo-calls. 8) Are Jews genetically smart? 9) Rethinking the age of consent.