There's no reliable evidence that GM crops are dangerous to eat. On the other hand, they aren't the best way to reduce world hunger, and you can basically roll your eyes at anybody claiming GM crops are environmentally sustainable. Greg Jaffe cuts through the myths of GM food at The Atlantic. Read the rest

The United States Geological Survey has an interesting FAQ report on dowsing — the practice of attempting to locate underground water with divining rods. It's got some interesting history and comparisons between dowsing and modern hydrology. The part on evidence for and against dowsing, though, is pretty sparse. If you want more on that, The Skeptic's Dictionary has some deeper analysis. The basic gist — what little research there has been suggests the successes of dowsing aren't any better than chance. (Via an interesting piece by Mary Brock at Skepchick about dowsing in the wine industry.) Read the rest

Over the years, I've been really impressed with the stuff I've heard about microfinancng charities like KIVA. The idea of helping people in developing countries launch and support small businesses, changing their lives and the lives of their children, makes a lot of sense. And the personal stories that go with microfinancing are pretty appealing.

I'm starting to re-think my opinions on microfinancing, however, after reading some of the research done by GiveWell.org, an organization that casts an evidence-based eye on what different charities do and whether they actually get the results they claim.

It's not that microfinancing is bad, per se, GiveWell says. It's just that the system doesn't measure up to the hype. And if you've got a limited amount of money to spend on helping other people, there might be more effective ways to do it that produce more bang for your buck.

GiveWell has written a ton on this, but I'd recommend starting with a blog post of theirs from a couple of years ago called 6 Myths About Microfinance Charities that Donors Can Live Without. This piece provides a succinct breakdown of what questions you should be asking about microfinance charities, and provides lots and lots of links for deeper digging. The myth that surprised me the most:

Myth #6: microfinance works because of (a) the innovative “group lending” method; (b) targeting of women, who use loans more productively than men; (c) targeting of the poorest of the poor, who benefit most from loans.

Reality: all three of these claims are often repeated but (as far as we can tell) never backed up.

I'm going to bookmark The Debunking Handbook, a quick-read pdf with all sorts of great advice for effectively countering misinformation. It's put together by the same people behind Skeptical Science, my go-to source for detailed, easy-to-understand debunkings of pretty much every climate-science-related myth you can rattle off. Read the rest

A great look at math, and real vs. imaginary Bell curve distributions. Thanks to Gideon for bringing this to my attention! Read the rest

Myths about menstrual cycles are a great example of why carefully collected data is important. Without that, it's extremely easy to see a pattern where none exists. For instance, there's no good evidence that menstrual cycles have anything to do with cycles of the Moon.

The evidence is also against there being such a thing as ladies synchronizing their menstrual cycles. I know. I know. It totally happened to you in college. I thought it happened to me, too. And there are few scientists who think the phenomenon is real. But the preponderance of evidence seems to be against them. Again (and this cannot be said enough) humans are really good at spotting patterns—even when patterns don't exist.

Kate Clancy, an anthropologist who studies the evolutionary medicine of women’s reproductive physiology, has a post on Scientific American blogs looking at the research that's poked holes in the synchronized periods hypothesis. A couple of the studies she talks about came out this year.

Maybe we should look to our primate relatives for evidence, then: in fact two papers have come out this year testing this hypothesis in primates! Setchell et al (2011) observed semi free-living mandrills, which is a kind of Old World monkey, a group to which the Great Apes belong. Out of ten observation-years of data, they found a single year that had significant synchrony… only to have that one year fail to be significant once they corrected for multiple testing. Multiple testing corrections are important because of the chance that if you test a hypothesis enough times you will get a spurious significant result (and for a brilliant take on this, see this xkcd comic).

Levi's recommends freezing jeans, instead of washing them, as a way to save water. The idea is that freezing will kill the bacteria that make your pants smell. But Stephen Craig Cary, an expert in low-temperature microbial life, begs to differ. Read the rest

Somebody in the Galway, Ireland, coroner's office hasn't been watching Myth Busters. (Thanks, Tim Heffernan!) Read the rest

Some recent research is confirming what a lot of us have probably long suspected—there's a pretty reasonable scientific explanation for near-death experiences.

Recently, a host of studies has revealed potential underpinnings for all the elements of such experiences.

For instance, the feeling of being dead is not limited to near-death experiences—patients with Cotard or "walking corpse" syndrome hold the delusional belief that they are deceased. This disorder has occurred following trauma, such as during advanced stages of typhoid and multiple sclerosis, and has been linked with brain regions such as the parietal cortex and the prefrontal cortex—"the parietal cortex is typically involved in attentional processes, and the prefrontal cortex is involved in delusions observed in psychiatric conditions such as schizophrenia," Mobbs explains. Although the mechanism behind the syndrome remains unknown, one possible explanation is that patients are trying to make sense of the strange experiences they are having.

This story, by Charles Q. Choi, breaks down several common elements of near-death experiences the same way. But the fact that I found most interesting relates to who has "near-death" experiences. Turns out, it's not limited to people who are actually near death. Choi reports that a study of 58 patients who had had near-death experiences found that 30 of them weren't actually in danger of dying. They just thought they were. Read the rest

NASA to the Internet: Comet Elenin will not kill us all. (Via Louie Baur) Read the rest

This amazing video was shot at an astronomical observatory in Hawaii. It's real, according to Bad Astronomy blogger Phil Plait. In fact, there's another camera that captures the same phenomenon from a different angle. So the question becomes, "What the hell is that?" Plait details a possible explanation, worked out by members of the Astronomy Picture of the Day forum.

... what leaps out is that the expanding halo is limb-brightened, like a soap bubble, and fades with time. That strongly points toward something like a sudden impulse of energy and rapid expansion of material, like an explosion of some kind. Note that the ring itself appears to be moving, as if whatever caused it was moving rapidly as well.

Asterix board member calvin 737 was the first to suggest it might be related to a Minuteman III missile launch around that time. As more people on the forum dug into it, the timing was found to be right. The missile launched from Vandenberg Air Force Base (in California) at 03:35 Hawaii time, just minutes before the halo was seen. I noticed the stars of Cassiopeia are visible in the webcam, so the view was to the northeast, which is the right direction to see the missile as well. OK, the timing and direction are perfect, so the rocket is clearly the culprit... but how, exactly?

[An idea posted by board member neufer] was that this was from a detonation charge in the missile's third stage. There are ports, openings in the sides of the third stage.

Xeni brought this to my attention yesterday. Over at Scientific American, Michael Moyer takes a critical look at an Al Jazeera story about a recent study purporting to show that infant deaths on the American West Coast increased by 35% as a result of fallout from the Fukushima Daiichi nuclear power plant meltdown.

At first glance, the story looks credible. And scary. The information comes from a physician, Janette Sherman MD, and epidemiologist Joseph Mangano, who got their data from the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Reports—a newsletter that frequently helps public health officials spot trends in death and illness.

Look closer, though, and the credibility vanishes. For one thing, this isn't a formal scientific study and Sherman and Mangano didn't publish their findings in a peer-reviewed journal, or even on a science blog. Instead, all of this comes from an essay the two wrote for Counter Punch, a political newsletter. And when Sci Am's Moyer holds that essay up to the standards of scientific research, its scary conclusions fall apart.

Sherman and Mangano tally up all the deaths of babies under one year old in eight West Coast cities: Seattle; Portland, Ore.; Boise, Idaho; and the California cities of San Francisco, Sacramento, San Jose, Santa Cruz and Berkeley. They then compare the average number of deaths per week for the four weeks preceding the disaster with the 10 weeks following. The jump--from 9.25 to 12.5 deaths per week--is "statistically significant," the authors report.

Let's first consider the data that the authors left out of their analysis.

Or: Maybe Facebook isn't the best source for science and health news. An interesting debunking.

You know the game, Telephone? You line up a bunch of people and the person on one end whispers something to their neighbor, who repeats it to the next person in line, and so on. At the other end, the last player says the secret out loud, and then everybody gets a nice chuckle from how distorted the secret has become as it was passed along the line. I rather like Telephone the game. But, lord, how I hate when it happens in real life.

So, this week on the Internet, there's a story circulating that claims scientists have discovered a foolproof, side-effect free cure for cancer ... but They (you know, "THEY") are preventing you from getting access to it. This story is like the end of a game of Telephone. There's some real (and interesting!) science going on, but by the time the story made it to Facebook the reality of a promising chemical compound that could be a good treatment for some types of cancer (maybe, scientists aren't sure yet) had become a first-rate conspiracy theory.

The compound in question is dichloroacetate (or DCA), and it's not really anything new. In fact, research into this compound has been going on long enough—and with enough attention from within the field of people who closely follow basic, laboratory chemical research—that I could almost do this entire debunking using only excerpts from four-year-old posts made by Orac, a surgeon and scientist who blogs about this kind of stuff in a much more specialized way than I do. Read the rest

Yet another aftershock of the March 11 earthquake hit Japan today. So it seems like a good time to bring up the United States Geological Survey's fascinating FAQ on earthquake myths. Here's one new thing that I learned.

Q: Will California eventually fall off into the ocean?

A: No. The San Andreas Fault System, which crosses California from the Salton Sea in the south to Cape Mendocino in the north, is the boundary between the Pacific Plate and North American Plate. The Pacific Plate is moving northwest with respect to the North American Plate at approximately 46 millimeters per year (the rate your fingernails grow). The strike-slip earthquakes on the San Andreas Fault are a result of this plate motion. The plates are moving horizontally past one another, so California is not going to fall into the ocean. However, Los Angeles and San Francisco will one day be adjacent to one another!

Image: Photo taken by Wikipedia user Ikluft, used via CC Read the rest

Last week, Ann Coulter told America that exposure to low levels of radiation might actually be a good thing. And most of America went, "What?"

But, while Coulter seems to have overstated the case, there is, apparently, a not-widely-accepted scientific theory behind what she said. PolitiFact ended up rating Coulter's claim as "Barely True" because of hormesis—a controversial idea based on some early studies in the United States which seemed to show that regions with higher natural levels of background radiation had a lower incidence of cancer. The trouble (for Coulter) is that hormesis is far from being a proven concept.

[Fred] Mettler [a radiation expert at the University of New Mexico] cautioned not to read too much into such studies, however.

"In addition to variability in populations, statistical uncertainties, potential bias factors, and chance, on one hand there will be instances in which there was less effect than predicted," he wrote. "This is all understandable without invoking a unifying hypothesis of hormesis."

Owen Hoffman, a radiation-risk expert at Senes Oak Ridge Inc., a center for risk analysis, said that studies show low levels of radiation might eliminate some cancer but initiate others.

Hoffman also pointed to the work of Dr. Charles Land of the National Cancer Institute, who "has shown in several of his recent publications that there is considerable uncertainty in the estimation of radiation risk. In his work, he does not give much credibility to the possibility that radiation induces a protective or beneficial effect.

In 1842, P. T. Barnum exhibited the infamous Feejee Mermaid at his museum in New York City. Newspapers were given a woodcut of lovely bare breasted female mermaids to publicize the attraction, but when the crowds arrived to see the mysterious creature, it turned out to be a gruesome taxidermy gaffe consisting of the top half of a small monkey and the bottom half of a large fish.

When I was about 12 years old, I viewed Barnum's very own Feejee Mermaid at the Ripley's Believe It Or Not Museum on Fisherman's Wharf in San Francisco. It invaded my consciousness and my dreams and became an object of great importance to me. I developed a theory on entertainment from thinking about it... Never be afraid to promise more than you can deliver as long as you deliver something truly remarkable and surprising. I'm sure this is the credo that stage magicians and circuses used to operate on. But today we seem to have lost the capacity for imagination that's required for this sort of pitch to work. I hate the literalism of the modern world!

But anyway, I digress... The Feejee Mermaid became a strong object of desire for me. In my daydreams as a child, I would secretly scheme to break in and steal the mermaid from the Ripley Museum (with no intention of ever actually doing it.) I discovered that the Ripley's Museum in Hollywood had the one true Barnum Feejee Mermaid too... and it appears that every Ripley's Museum in the country has it. Read the rest

Mind Hacks blog Googles the phrase "psychologist says", with headesky results. The problem: "Psychologist" doesn't always mean what you think it means. Some stories quoted from peer-reviewed research, others turned to therapists with little-to-no academic or research experience, and everything in between. Read the rest