I Sense a Pattern Here

The Atlantic site has a new article by one of their regular writers, Megan Garber.  The title is "There Are (Probably) Billions of Earth-Like Planets in the Universe."  Well, "probably" and a dollar will get you on the bus, here in Bloomington anyway.  The article is typical of its kind -- the rabble-rousing three-cheers-for-science kind which inflates what we know or can do -- in its careful but sneaky use of qualifiers that undercut the impression the writer wants to give.  For example:

Here's more potential evidence against notions of Earthian exceptionalism: The team estimates that 22 percent—essentially one in five—of sun-like stars have potentially habitable Earth-size planets.

"Potential", twice in two sentences (or one compound one)!  The research Garber is writing about doesn't even offer evidence, only "potential" evidence, and an "estimate" of numbers.  Of course "potential" (along with its cousin "possible" and its half-sibling "suggests") is misused in all kinds of writing, in the hope the reader will ignore it and believe what is potential, or potentially potential, is actual.  Even "probably" is an overstatement in the article's title.  We still have no real basis for computing probabilities about the number of planets, let alone "potentially" habitable ones, in the universe, and Garber's article doesn't provide any real evidence that the situation has changed.

Is Extremophilia a Lifestyle Choice, or Are You Born That Way?

The July/August 2013 issue of Popular Mechanics has an article about "The Case for Alien Life."  I've been trying to find it online, but haven't been able to track it down so far.  I have found thought-provoking articles like "Why 3D Doesn't Work for TV, But Is Great for Gaming" and "When Will the NFL Broadcast in 3D?", however, plus some other articles on the same theme in their archive.

I realize that it's less unwieldy than, say, "extraterrestrial," or "elsewhere in the universe," but it bothers me that their writers keep using the word "alien."  If we ever do find life elsewhere in the universe, we will be the "aliens."  I thought this was funny, for example.

"Titan is so cool," says Peter Ward, who leads NASA-funded astrobiology research at the University of Washington. "Titan is the most exciting place in the solar system astrobiologically. It has the most exciting chemistry set in our solar system by far. If there's life on Titan, it's alien life--really alien life."

If there's life on Titan, it's just plain life.  We'll have to rework our conceptions of the word "life" if it turns out that Titanian life is significantly different in structure and form from life here on Terra.  I was thinking that PM was just dumbing down its analysis for the rubes, so it's comforting to find a scientist who's pretty dumb himself.  Based on our results so far, no matter how astrobiologically exciting Titan may be, the most likely projection is that we won't find any life there.  But true believers never give up.  From the same earlier article:

"Are there ETs in the cosmos? Probably," says Michael Shermer, founder of The Skeptics Society, which publishes Skeptic magazine, and investigates claims of extraterrestrial contact. "It's a big place. There are lots of opportunities for life. But that's a separate question from, 'Have they come here?'"

Shermer is still too optimistic with that "probably."  A hardcore skeptic would admit that we have no idea about the probabilities of life elsewhere, because we have only one actual case to work with: our own planet.  It's not unreasonable to speculate that life could turn up elsewhere, but so far the evidence is nil.  There's no probability here, just wishful thinking.  As the author of a book called Why People Believe Weird Things, Shermer should know better. But everybody's skepticism has its limits.

So I'm working from the print version of the article.  It's pretty standard stuff, the same old come-on that science propagandists have been trotting out for decades.  I'm sure Neil DeGrasse Tyson would love it, if only to gin up enthusiasm for the scientific enterprise among the rabble.

Only one planet has been proven to support life: Earth.  But evidence is mounting that we are not alone.  Scientists now think the galaxy contains at least 11 billion Earth-size worlds orbiting in their stars' habitable zones, where life is most likely to be found.  And new studies show that strange creatures may thrive far beyond that boundary -- on nearly any of the galaxy's 100 billion planets for their moons.

Nothing there is actually false, but it promises so much more than it can deliver.  None of this is "evidence ... that we are not alone".  The main headings of the article are more of the same.  "Water is commonplace, not rare."  Maybe so, but liquid water still looks rare as far as this article shows.  There's "evidence of ancient freshwater" on Mars, for example, and "research conducted by Jay Farihi at the University of Cambridge suggests that liquid water is actually typical of rocky planets such as our own."  "Suggests" -- a very popular word in reports of scientific research, as well as in academic writing -- and a token will get you on the subway.  It's like a hunter bragging about the magnificent specimen he's going to bag.

"The kind of chemistry that could have been used for life exists everywhere," says David Blake, a geologist on the Curiosity rover team.  "There's no reason that life wouldn't have happened on other solar systems.  The ingredients are everywhere we look."

Even on earth, those ingredients don't always combine to produce life.  It's a big leap from having the ingredients to having the recipe.  This also recalls the Fermi Paradox: it's not unreasonable to think that there should be life elsewhere in the universe, but so far there's no evidence that there is.  It's easy to construct what appear to be overwhelming odds in favor of the existence, not just of life, but of intelligent life that could be broadcasting radio waves we should be able to detect.  So far, however, nada.  Enthusiasts have plenty of good reasons why we haven't detected anything, but as time goes on they sound more and more like enthusiasts explaining why Jesus is still late for his rendezvous with destiny.  You'd think science fans -- let alone scientists -- would learn a certain modesty for the claims they make, but we still get articles like "The Case for Alien Life."

Heading number two is "Life is more versatile than we believed."  The evidence here still comes from the Earth, the only planet we know harbors life.

The study of extremophiles was already well-advanced a decade ago, but work such as Christner's is continuing to extend the known boundaries of life.  Organisms thrive in the deepest reaches of the ocean, in the driest of deserts, and in the saltiest of sands. The red algae Galdiera sulphuraria can prosper in sulfuric hot springs and old mineshafts with waters as caustic as battery acid.  Even our skies are swirling with microbes, a paper published in January revealed.

And so on and on.  How much does all this matter, if there are all those billions of Earthlike planets out there?  It sounds as if there should at least be microbes on Mars, but so far our probes haven't come up with anything.  (Show us on the doll where Curiosity touched you, Mars.)  At least the first few times a probe landed there, the media were full of stories about how the high-tech equipment onboard would be able to detect life if it was there.  The equipment even got positive results at first, but then it turned out that the high-tech equipment wasn't all that brilliant after all; from what I've seen, the promoters have been more careful in the promises they've made for their gadgets.  I don't think it counts against Science that life is hard to detect in a strange environment; that itself is interesting.  But it does make me more skeptical of the claims scientific evangelists make.

Heading three: "Planets are the rule, not the exception."  So it seems.  But so far this planet is the only we know of that contains life.  There follows a two-page spread of cartoon "Aliens: How Sci-Fi Movies Can Save Humanity."  I mentioned Neil DeGrasse Tyson earlier, the voluble evangelist for science who thinks that all's fair in getting more funding for NASA.  He'd like a new space race, like the old Cold War space race, but I'm not sure we could have that without returning to the specific conditions of the Cold War; no, thanks.  It's occurred to me that one reason for declining interest in and support for the US space program might be the improved special effects of science-fiction movies and television, compared to which real space flight as we have it now looks grim, dull, and primitive.  After all, in the movies they just pass through a space warp or turn on the warp drive and bingo! they're in another galaxy.  Why aren't we building a warp drive now?  Why couldn't some smart entrepreneur build one in his garage?  They did it all the time in 1950s science fiction, which was Scientific Prophecy so it must have come true.

There's a lot of justified criticism of popular science reporting, but popular media walk a fine line.  They're supposed to get the facts right, but at the same time scientists want them to be cheerleaders for the Onward March of Progress and more funding for research, and to report their speculations as if they were fact.  You can't do both.  Getting the facts right won't inspire as many kids to want to be astronauts and scientists as the latest sci-fi spectacle.  Tread lightly, O skeptics, for you are treading on their dreams.

Keep Telling Yourself: It's Only a Cartoon ...

I very rarely disagree with XKCD's cartoons, but this one baffled me. The explanation here doesn't help.

Yes, I know, it's a cartoon, not a philosophical or scientific argument. But the cartoonist is very serious about his math and his science. And so much here is wrong.

I'm sure that gliding in a wingsuit like the one depicted is fun; I've fantasized about free flight myself, many times. But the invention of such toys hasn't interfered with humans' determination to keep fighting until we've rendered ourselves extinct, so you can't resolve the Fermi Paradox by postulating that intelligent species on other planets just got so caught up in self-powered flight that they never bothered to build spaceships or some kind of long-distance communication.

Oh yes, the Fermi Paradox. It points to the conflict between many scientists' conviction that because the universe is so vast, there should be some other intelligent, spacefaring, radio-wave beaming species out there. If they exist, some should have been around long enough that we on earth could have picked up their transmissions, and if they've developed faster-than-light travel, they should have found us and paid us a visit by now.

I used to go to the occasional observatory / planetarium presentation where an astronomer would talk about the chances of life elsewhere in the universe. After a couple of them, I realized that the numbers they would toss out ("If one in ten thousand stars has planets, and one in ten thousand of those planets are the right distance from their star and has the right conditions for the development of life, and life develops on one in five hundred, etc.") were sheer fantasy masquerading as science because a scientist was reciting them, and lost interest. We have no basis for assigning probabilities in this area, because we have no data. We know of only one star with a planet at the right distance and with the right conditions for the emergence of life -- this one. Until we know of a good many more, we can't assign any probabilities at all.

Various attempts have been made to explain why we have found no trace of other civilizations. What XKCD calls the Corliss Resolution, after a wacko who likes to jump from high places with his wingsuit, doesn't do the job. First, if (as the explanation says) it's more fun to fly than to do calculus, then everybody would be out jumping off buildings -- only we wouldn't have any tall buildings because flying/gliding is presumably more fun than building skyscrapers too -- and calculus would never have been invented.

Maybe XKCD is postulating not the invention of self-powered flight on all planets that harbor intelligent life, but the evolution of quasi-avian species on all such planets, that such species wouldn't bother to invent space travel because they were too busy flying, and no other intelligent species would evolve there. Remember the vast numbers of stars out there, just in our galaxy let alone beyond; remember that the case for life outside our solar system rests on those numbers, which make it reasonable to speculate that there must be some other earthlike planets and other intelligent species somewhere in the universe. In order to make the Corliss Resolution plausible, someone would have come up with a reason to believe that life on every other life-bearing planet is too happy gliding to do anything else. (I think it's interesting that XKCD writes of "space colonization" rather than "space exploration." Does he want us to be colonized by kindly ETs?)

This shoots down the motive of much (if not all) scientific speculation about life on other worlds: that the emergence of life on earth is not a one-in-a-jillion fluke, that other organisms like us exist, that we are not alone in the universe. Even if the Corliss Resolution did turn out to be true (and we'll never know if it is), it would mean that the earth is unique and human beings are alone. That might be a good thing, but it would be a devastating disappointment to the many science geeks who've been inventing probabilities for the existence of extra-terrestrial life, to convince themselves and others that it's out there; it would destroy a major pillar of their faith.