Image: Oct. 28, NASA/NOAA polar orbiting satellite. Detail above, full below.

Last year, I wrote a piece for BoingBoing about destructive storm systems and why it's so difficult to say, in concise sound-bite form, what relationship that destruction has to climate change. In that case, we were talking about tornadoes. But over the last couple of days, lots of people have been having roughly the same conversations about Hurricane Sandy. When the clouds have passed and everybody is done sleeping in airports, people are going to want answers. Was this an unavoidable act of nature? Or was this something caused directly by changes to Earth's climate that have happened because we burn fossil fuels which increase the concentration of carbon dioxide in the atmosphere?

Again, there's not an easy answer. And, again, part of the problem here is that we're expecting science to operate on the scale of American media news cycles, which doesn't really work. We want to talk about this while the storm is raging or, barring that, at least immediately afterwards. But scientists aren't really going to have anything particularly deep to say about this specific storm for months, if not years. During that time, data will be analyzed and compared, and other events will happen, and that's really the stuff that we need in order to say much of anything other than, "We don't know for certain." In some ways, expecting anything else means forcing scientists to speculate and extrapolate in ways they aren't usually comfortable with and that aren't a terribly great way to understand the big picture.

But there's also something new, that I kind of didn't really think about when I was writing that post on the tornadoes. The answer to these questions also really depends on the motivations behind why you asked, and what it is that you really want to know.

The New York Times Sunday Review had an article this week linking autism with the hygiene hypothesis. Written by Moises Velasquez-Manoff, the piece is part of the Times' opinion coverage, not reported news. It was also one of those sort of stories that comes across as highly persuasive ... until you start looking at the details. About halfway through reading it yesterday, it occurred to me that Velasquez-Manoff was making a lot of big statements—"perhaps 1/3 of autism, and very likely more, looks like a type of inflammatory disease", for example—without citing the sources to back those statements up.

That's easy to do when you're writing a relatively short article summarizing the contents of a much bigger book, as Velasquez-Manoff seems to be doing here. But the problems go deeper than that, according to biologist and science writer Emily Willingham. In a must-read blog post, she goes through the NYT piece and points out many flaws in argument and detail. The main problem, though, is a pretty simple one: Moises Velasquez-Manoff presents what seems to be a largely speculative hypothesis as sure-fire truth. To make that case as persuasive as it is, he leaves out lots of evidence that doesn't match up with his thesis.

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Over at Download the Universe, Ars Technica science editor John Timmer reviews a science ebook whose science leaves something to be desired. Written by J. Marvin Herndon, a physicist, Indivisible Earth presents an alternate theory that ostensibly competes with plate tectonics. Instead of Earth having a molten core and a moveable crust, Herndon proposes that this planet began its existence as the core of a gas giant, like Jupiter or Saturn. Somehow, Earth lost its thick layer of gas and the small, dense core expanded, cracking as it grew into the continents we know today. What most people think are continental plate boundaries are, to Herndon, simply seams where bits of planet ripped apart from one another.

The problem is that Herndon doesn't offer a lot of evidence to support this idea.

Once the Earth was at the center of a gas giant, Herndon thinks the intense pressure of the massive atmosphere compressed the gas giant's rocky core so that it shrunk to the point where its surface was completely covered by what we now call continental plates. In other words, the entire surface of our present planet was once much smaller, and all land mass.

I did a back-of-the-envelope calculation of this, figuring out the radius of a sphere that would have the same surface area as our current land mass. It was only half the planet's present size. Using that radius to calculate the sphere's volume, it's possible to figure out the density (assuming a roughly current mass). That produced a figure six times higher than the Earth's current density — and about three times that of pure lead. I realize that a lot of the material in the Earth can be compressed under pressure, but I'm pretty skeptical that it can compress that much. And, more importantly, if Herndon wants to convince anyone that it did, this density difference is probably the sort of thing he should be addressing. He's not bothered; the idea that the continents once covered the surface of the Earth was put forward in 1933, and that's good enough for him.