Bang, We're Dead
How our universe will end, and another will be born.
The universe is a potentially endless series of Big Bangs, according to a new theory. Most scientists think the universe began 14 billion years ago with the Big Bang and will keep expanding and scattering into nothingness. The new theory says a gap between the current theory's predictions and emerging data can be explained if the universe is at least a trillion years old, probably driven by a cycle of bangs. In fact, the authors say, there's no reason to assume its age is finite. Old forecast: We and our descendants will dissolve into smithereens, along with everything we've built and done. New forecast: We and our ancestors will be blasted into smithereens, along with everything we've built and done.
Holding a gun may trigger testosterone and aggression. In a small study, young men were given either a handgun or a board game; testosterone spiked in those who handled the gun, but not in those who handled the game. Given the opportunity to add hot sauce to a drink for the next participant, the gun handlers added three times as much as the game handlers did. Skeptics' argument: Maybe the guys who received the gun added extra hot sauce because they figured that's what was expected of them. Rebuttal: That wouldn't explain the testosterone spike. (For Human Nature's take on male-female differences in eagerness to punish, click here.)
Britain will let fertility clinics weed out embryos that have genes for adult cancer. The old rule allowed screening only for genes that caused childhood diseases; the new rule allows screening for genes that 1) don't affect the child until later in life, 2) increase the probability of a disease but don't guarantee it, and 3) relate to diseases that are often treatable. Critics' argument: It's another step down the slippery slope. Wait till we find all the genes for IQ, obesity, and shortness. British regulators' arguments: 1) Medicine's job is to prevent suffering, which these genes cause. 2) The genes confer an 80 percent probability of cancer, which is close to a guarantee. 3) The diseases often strike by age 50, which is pretty young. 4) We're not saying it's always OK; we'll just consider each screening request on its merits. (For Human Nature's takes on embryo screening and genetic engineering, click here and here.)
A Catholic parochial school teacher was fired for undergoing IVF. She and her husband resorted to IVF after five years of trying to bear children. When she told her principal she was trying it, he said it might violate her employment contract. Four days after she announced her pregnancy, she was fired. IVF violates Catholic doctrine by separating procreation from sex (since the fertilization is in vitro) and by entailing, in some cases, the destruction or desertion of spare embryos. Teacher's arguments: 1) I was just trying to have kids; isn't that what marriage is for? 2) We respected Catholic concerns by destroying no embryos and avoiding donor eggs or sperm. 3) Firing me was pregnancy discrimination. 4) My bosses let other couples get away with IVF. Employer's arguments: 1) She's "a fine teacher, but for the fact that her public announcement of her intentions was in direct violation of the teachings." 2) Religious schools are allowed to discriminate on the basis of their teachings. 3) We don't invade teachers' privacy; we had to fire this one because she made her violation impossible to ignore. Statement of the employer's attorney on birth control: "If an employee were to publicly espouse that he is going to engage in contraception with his spouse that is in direct violation of church teaching ... that employee would be terminated." (For Human Nature's takes on the political battles over IVF, click here and here.)
Gene transfer cures cancer in mice. Scientists found a mouse that defeated cancer injections that killed ordinary mice. When they bred it with ordinary mice, offspring inherited the immunity. When they injected its white blood cells into ordinary mice with cancer, "In every case, the cancers were destroyed, even if the cells were injected at a point distant from the tumor. Healthy tissues were not affected. The mice that received the cells, furthermore, were protected from new tumors for the rest of their lives." Preliminary tests suggest some humans may have similar immunity. Warnings: 1) The results have yet to be replicated. 2) We haven't identified the gene. 3) We may not find it in humans. 4) We've seen cancer cured in mice before. (For Human Nature's take on genetic engineering, click here.)
In 10 years, self-reported oral sex has more than doubled among people aged 12 to 25, according to a comparison of 1994 and 2004 data in Baltimore clinics that manage sexually transmitted diseases. In a sample of more than 6,000 young people, the percentage of males reporting oral sex in the preceding 90 days rose from 16 to 32; the percentage of females reporting oral sex rose from 14 to 38. Meanwhile, the percentage of females reporting anal sex rose from 3 to 5.5. Interpretations: 1) More teens and young adults are having oral sex because they think it's safer than vaginal sex. 2) That's true of some infections but not others. 3) This is foiling urine tests, which are supposed to diagnose STDs but don't catch oral or rectal infections. 4) We'll have to warn kids more explicitly about the risks of various activities. (For Human Nature's take on the risks of oral vs. anal vs. vaginal sex, click here.)
Lesbian brains differ from straight women's brains. Last year, a study showed that gay men, like straight women and unlike straight men, processed a male pheromone in a sex-related part of the brain (the hypothalamus) but processed a female pheromone in a scent-related part of the brain. Now the authors of that study report differences among women: 1) Lesbians, like straight men, prefer the female pheromone and find it less irritating than the male pheromone. 2) Straight women find the female pheromone more irritating. 3) Straight men and women process same-sex pheromones in the scent area but process opposite-sex pheromones in the hypothalamus. 4) Lesbians process pheromones of both sexes in the scent area. Interpretations: 1) Sexual orientation is biologically based, not a choice. 2) Sexual orientation is more biologically based in men than in women. (For a summary of the study of gay men, click here. For Human Nature's take on gay marriage, click here.)
Being fat may improve your odds of surviving intensive care. In a study of nearly 1,500 lung-injured ICU patients, the thinnest "had the highest risk-adjusted odds of hospital mortality," while the fattest had the lowest risk. Researchers' theories: 1) Fat people are given medicine to prevent blood clots, which boosts their chances of survival. 2) Thin people die of the "underlying diseases" that made them thin. (For Human Nature's takes on the war on fat, click here and here. For updates on the benefits of coffee, click here and here. For the benefits of chocolate, click here and here. For the benefits of alcohol, click here and here.)
Teens who take virginity pledges can't be trusted, according to an analysis of follow-up surveys. Findings: 1) 52 percent of pledgers denied a year later that they'd pledged. 2) Among pledgers who later admitted to having sex the year after the pledge, 73 percent denied they'd pledged. 3) Among pledgers who conceded in the first survey that they'd had sex, nearly one in three claimed a year later that they'd never had sex. 4) Pledgers were four times as likely as non-pledgers to recant previous admissions that they'd had sex. Researchers' conclusions: 1) Teens lie. 2) Pledgers lie more. 3) Born-again pledgers (those who pledge after having sex) lie the most. 4) Pledges fail. 5) We have no idea what works or what the truth is, because all this revisionism makes the data worthless. Conservative objection: Stop dishonoring pledgers by questioning whether they honor their pledges. (For the risks of French kissing, click here. For the superiority of intercourse over masturbation, click here. For Human Nature's take on anal sex, click here. For sex with teachers, click here.)
Will Saletan covers science, technology, and politics for Slate and says a lot of things that get him in trouble.