Monday, December 03, 2007

The Lopsided Universe

Messier 101: A counter-clockwise spiral galaxy

I've always had a passionate amateur's interest in astronomy and once, long ago, hoped it might become more. In college I taught astronomy labs and helped run my campus's small observatory, and "astronomer" seemed like just about the coolest thing anyone could ever put on a business card. I just couldn't convince a grad school to agree with me.

That's all right. The nice thing about astronomy is you can keep up with it as a civilian. You can even do it; I have a small scope I don't pull out too often because my house is surrounded by street lights, but in theory it's a field where amateurs often put together equipment just as good as the professionals' and can still make a contribution.

A few years ago, I was one of millions who turned over a portion of my computer's processing power to help find ETs. A group called SETI at Home (SETI = Search for Extraterrestrial Intellligence) developed a program that anyone could install to help analyze signals captured by a radio telescope. The program works like a screensaver. Whenever your computer is idle it switches over to analyzing data, automatically reporting its results to the researchers and downloading another batch of signals. By distributing the task among legions of ordinary computers, the SETI folks got more done faster than if they'd used the world's most powerful supercomputer. As far as I know my computer never found anything interesting. In fact, as far as I know, the entire project hasn't found much interesting, which is kind of an interesting result in itself. It was fun until they issued an update that gave my computer indigestion and I stopped participating. But it's been a while and I think I might give it another try.

More recently, I've been looking at smudgy little space photos for an effort called Galaxy Zoo. Galaxy Zoo aims to classify galaxies, and its strategy is similar to SETI at Home's: spread out a job too daunting for a small team of researchers among millions of amateurs instead. Once you sign up and pass a test to prove you know what a galaxy looks like, you can log on to Galaxy Zoo and sort them to your heart's content. There's nothing automated about it. You manually click through image after image, deciding whether each depicts an elliptical or spiral galaxy (the two main types) and, if it's a spiral, whether it turns clockwise or counter-clockwise. In practice it's not easy--everything looks like a dim fuzzy blob after a while--but the Galaxy Zoo researchers at Oxford University show the same images to several people to reach consensus. In fact, I got an e-mail from them this morning explaining that each target galaxy has been looked at more than 30 times, and our amateur results agree with a smaller sampling classified by professionals. So far so good.

Here's the bizarre and interesting part: as this article in the U.K.'s Daily Telegraph newspaper explains, the universe seems to have a lot more galaxies spinning counter-clockwise than clockwise.

That is a deeply astonishing result. First, understand that a spiral galaxy that appears to be wound counter-clockwise would look clockwise if we were on the other side of it. The direction of a galaxy's spin is nothing more than an accident of where you happen to be when you look at it. Second, one of the fundamental principles of astronomy is isotropy--that is the idea that, on average, the universe is pretty much the same no matter which direction you look and there's no special vantage point that's better than any other. With that in mind, looking into space from our nowhere-special perspective, you'd expect to see nearly equal numbers of clockwise and counter-clockwise galaxies. If you dump a million pennies on the ground, approximately 500,000 will be heads and 500,000 tails. It's the only result that makes any sense at all.

And yet, I and my fellow Galaxy Zoo galaxy classifiers say the cosmos, as seen from Earth's vantage point, strongly favors the counter-clockwise.

Clearly, I broke the universe.

The researchers are trying to figure out what it means, if anything. Analyzing more pictures might help solve the puzzle. My own suspicion is that they've discovered less about the universe than about the flawed eyes and minds observing it. When confronted by an indistinct image our brains find patterns and fill in details that aren't really there, and I think it's possible that maybe--maybe--there's something hard-wired into us to discern counter-clockwise patterns more readily than clockwise. Like seeing ghostly faces in the static.

That sounds like a reach, but it makes a million times more sense to me than the alternative. In any case, it'll be cool to follow and see how it turns out. Which is the entire point.



Mike said...

Heh. Not sure astronomy is the best hobby for someone who wants to "follow and see how it turns out."

Sherwood Harrington said...

I'd not heard of this before, and it's bizarre for all the reasons you point out.

My money is on it being due to something behind the classifiers' eyeballs (like the "canals" of Mars), but why such a preference for counterclockwise?

I also wonder why the question about CW or CCW was even asked.

Brian Fies said...

Mike, very very funny, and true. However, we are lucky enough to live in the era of astronauts and space probes. I remember when the best images we had of other planets were fuzzy dime-sized blobs shot from Earth; now we've seen them all up close except Pluto, and have mapped Mars better than some parts of Earth (something else those darn kids today take for granted). In that sense, things happen fast and there's always something new to marvel at. Anyway, I don't think I'd care to stick around long enough to watch the sun bloat into a red giant.

Sherwood, the bias must lie with the observers and not the observed... but isn't it interesting to ask, "What if it's real?" My first speculation on the counter-clockwise preference was that it might be related to handedness: maybe, when told to find a spiral structure in ambiguous data (I think that's important--we're deliberately looking for spirals), right-handers lean counter-clockwise and left-handers lean clockwise? I dunno, but it seems like a psychologist could devise some good experiments to find out.

I can only guess that they asked the question because they suspected something was funky before they started.... In any case, I think it's an interesting result either astronomically or neurologically.

And I envy you your business card.

ronnie said...

      Sherwood Harrington
"America's Fighting Astronomer"

Galaxies identified, distant stars classified, great-big-ginormous telescopes patiently explained for the astronomically-impaired.

Licensed, registered, certified and recognized by the High Council of the Zorxian Empire.

Sherwood Harrington said...

Licensed, registered, certified and recognized by the High Council of the Zorxian Empire.


ronnie said...

OMG Did I say Zorxian?

Because I totally meant Ottoman.


Honest. I swear. Seriously. Ottoman.