It’s not easy to survive century after century, through droughts and storms and oscillations of the climate. So California’s majestic coastal redwoods have developed a few tricks, like their great height: The trees can grow to more than 350 feet high, allowing their treetops to pull in moisture from the fog to keep their water levels refreshed. But, according to a new study in the Proceedings of the National Academy of Sciences, the fog is on the decline, which could spell trouble for redwoods and other area species.

Fog often rolls ashore along the California coast from June through September. The hot, dry inland air rises and creates a vacuum that sucks in the cold, vaporous air from over the ocean [Wired.com]. While the small strip of land about 50 miles inland from the coast where the redwoods live is dry and hot, this influx of moisture keeps the giant trees hydrated.

To obtain a historical record of coastal fog, the researchers looked at data on ceiling heights recorded hourly at several airports from 1951 to 2008. And they extrapolated back to 1901 using long-term land temperature data [The New York Times]. With the sea becoming warmer, less fog formed in the first place: Coastal fog cover decreased by more than an hour a day since 1951, researchers Todd Dawson and James Johnstone found. Temperature changes affected the fog, too. The coast has heated up faster than the redwood’s inland habitat, lessening the temperature difference between the two, which lowers the force pulling the fog inland. As a result of all this, the scientists propose that the redwoods receive at least three hours less fog per day in the summer than they used to.

Redwoods are tough enough to survive anyway, the researchers say, but there’s another problem. “As fog decreases, the mature redwoods along the coast are not likely to die outright, but there may be less recruitment of new trees” [Reuters], says Dawson. That means fewer seeds are likely to sprout and take root along the coast, and then to grow to maturity. In addition, climate scientist Phil Duffy tells Wired.com that we shouldn’t focus exclusively on the towering, awe-inspiring sequoias, because lower levels of fog will affect many ecosystems that rely on it for moisture.

Related Content:
DISCOVER: The Strange Forests That Drink—And Eat—Fog
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80beats: Is Google the Guardian Angel of Rainforests?

Image: flickr / morgenlandfahrer

(If you haven’t yet heard the first episode of the new Point of Inquiry, you can listen here, and I also strongly encourage you to subscribe via iTunes from the same page.)

The second insight from my chat with Paul Offit involved who he felt deserved the chief blame for the now notorious 1998 Wakefield paper (which, essentially, presented a claim of correlation between getting the MMR vaccine and getting autism based on a tiny sample of children, with a rather questionable mechanistic hypothesis attached). Offit said, very candidly, that he didn’t blame the media for going gaga over the study when it was published; rather, he blamed the Lancet for publishing it in the first place. As he put it around minute 10:

I think journals are a public trust, and when that’s published in Britain’s oldest and arguably most respected general medical journal, the media is going to see that as information, they’re not going to see it just as a hypothesis raised, they’re going to see it as a study done. And for them, they’ll jump on it and say, “Here’s at least a cause of autism,” and scare the hell out of people. Which is what happened. I actually don’t blame the media for this. I think that when something is published in the Lancet, I can see where they would jump all over it.

I agreed with Offit 100 % about this. Journals have a peer review process, and weeks or months to determine which studies to publish, after imposing quality control protocols. Journalists then have less than a day, in many cases, to determine what studies to cover and how to cover them. So by the time a study comes out in a journal, especially a major one, there’s no chance that you can unring the bell by hoping for the media to impose quality control, or call B.S. on this new piece of “science.”

It just isn’t going to happen.

For me, that’s another important insight from the Offit interview. Stand by for still more, and in the meantime, you can listen to the podcast and subscribe here. And don’t forget to buy Paul Offit’s book Autism’s False Prophets if you don’t already own it…

Welcome to this week’s installment of the From Eternity to Here book club. Chapter Six is entitled “Looping Through Time.” It’s about both the logical paradoxes presented by time travel, and some of the obstacles to actually building a time machine (closed timeline curves) in general relativity.

Excerpt:

Everyone knows what a time machine looks like: something like a steampunk sled with a red velvet chair, flashing lights, and a giant spinning wheel on the back. For those of a younger generation, a souped-up stainless-steel sports car is an acceptable substitute; our British readers might think of a 1950s style London police box. Details of operation vary from model to model, but when one actually travels in time, the machine ostentatiously dematerializes, presumably to be re-formed many millennia in the past or future.

That’s not how it would really work. And not because time travel is impossible and the whole thing is just silly; whether or not time travel is possible is more of an open question than you might suspect. I’ve emphasized that time is kind of like space. It follows that, if you did stumble across a working time machine in the laboratory of some mad inventor, it would simply look like a “space machine”—an ordinary vehicle of some sort, designed to move you from one place to another. If you want to visualize a time machine, think of launching a rocket ship, not disappearing in a puff of smoke.

There might not be too much new to say about this chapter, as part of it appeared as an excerpt in Discover and we’ve already talked about that. But maybe you weren’t reading that post, in which case, it’s new to you!

There were three main goals in this chapter. The first was to explain what time travel would and would not be, in the context of general relativity — in particular, it would be just another form of travel through spacetime, not involving any disappearing and rematerializing at some other point in the past. The second was to go through some of the possible ways to make closed timelike curves (with wormholes or cosmic strings) and see how difficult it really was.

But the third and most interesting goal was to connect time machines to the arrow of time and entropy. At this point in the book we’ve only introduced these concepts somewhat casually — the careful exploration of entropy is in Part Three, which begins next week — so one could argue that a more logical presentation would have delayed this discussion for later. But sometimes there are considerations beyond logic; in particular, once we built up momentum with the entropy discussion, a digression on time travel would have seemed like wandering too far afield. That was my feeling at the time, anyway.

This is a really interesting aspect of time travel, which I think is dramatically under-emphasized in discussions about it: the real reason why traveling backwards in time makes us nervous is that it becomes impossible to define a consistent arrow of time. The arrow is very ingrained in how we think about the world, including the sense that the past is set in stone while we can still make choices that affect the future. In the presence of a time machine part of our personal “future” is already in the “past,” which seems to compromise our free will.

So be it! Our free will was always an approximation, if we are good materialists who believe in the laws of physics. But it’s a highly useful approximation. It’s always worth emphasizing, when you start talking about the paradoxes of time travel: the simplest and most plausible way out is to imagine that the universe doesn’t (and won’t ever) actually have any time machines.

I have mixed feelings about NASA, as is obvious if you’ve read my posts about it. But I think that they have done a simply fantastic and amazing job given how small their budget is. You might think NASA gets a huge amount of money — a lot of people do — but in fact they get only a tiny fraction of the federal budget.

The New York Times made this very very clear recently when they posted an interesting graphic depicting the national budget allocations. Take a peek:

[Click to enporkbarrelate.]

Can you find NASA on there? It’s actually listed under General Science, near the bottom right. That rectangle’s not very big, is it? And NASA is only a part of that section, so the space agency’s lion’s share is starting to look more like a kitten’s nibble.

Now, wanna have fun? Close your eyes and click randomly on the graphic. Did you click on NASA? No? Shocker. But this gives you another way to think of the amount of money NASA gets, compared to, say, the military^*. Statistically speaking, your chance of randomly picking NASA’s footprint on that graphic are about 1 in 125.

I’m still working out what I think about Obama’s new plans for NASA. I’m happy about the increase he plans to give them, but we can easily afford to increase NASA’s budget by a lot more. We spend more on pet food every year in the US than we do on NASA. What we spend every year on tobacco products is five times NASA’s annual budget, so I’m thinking the money is out there.

It’s not a matter of finding the money. It never is, and never has been. It’s a matter of finding the money in a way that isn’t political suicide for a politician. And that, I suspect, is because those of us who support space exploration haven’t made it politically expedient for everyone else to support it, too.

I don’t have a remedy for that. I’m just a guy with a blog, so I blog about it, trying to show people that space is exciting, interesting, and worth a few more tax dollars a year. The more people who know that, really know that, the better off we are.

Tip o’ the change purse to Fark.

You can watch it here. No “balance”–the guests, Dr. Snyderman and myself, strongly agree that vaccines don’t cause autism. Enjoy!

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Once again, link to the segment can be found here.