Blogs / Bad Astronomy

I won’t waste your time by first writing a lot of words. Let’s get right to the way cool picture:

That image is of the galaxy cluster CL0024+1652 (go look at the higher resolution version — it’s very pretty!), a galactic city located a whopping 5 billion light years away! That means the light we see from this cluster left it five billion years ago, so we’re seeing this structure as it was when the Universe was just 2/3 its present age. Almost every small object in that image is a galaxy, and all of them are held sway by the cluster’s gravity, orbiting the center like bees flying around a beehive.

It has long been thought that every large object in the Universe is surrounded by a halo of dark matter — unseen, mysterious, yet profoundly influential in the life of normal matter. Dark matter (or just DM for short) gives off no light, and does not interact with normal matter directly– a cloud of it could pass right through you and you’d never know. But, like regular old matter, it has gravity, and that can betray its presence.

I’ve gone over this before — Einstein postulated that gravity from matter bends space, like a bowling ball on a bed bends the mattress. Light will follow that bend in space the same way a marble rolled across the bed will curve from the bowling ball’s dip. If there is some massive object out there in space, and some galaxy beyond it, the light from the more distant galaxy will bend as it passes by the intervening material. We see that as a distortion in the shape of the galaxy. This is called gravitational lensing, and can be used to map out the location of dark matter. So even though we cannot see DM directly, we can see its effects.

Clusters are a rich hunting ground for DM: it’s thought that DM helped normal matter form into large structures when the Universe was young. So clusters should still have lots of DM around them. It was also thought that in general, the DM halo around clusters would be roughly spherical, or maybe slightly elongated like a football. More exotic shapes weren’t really expected.

Until now, that is. CL0024_1652 is surrounded by a ring of dark matter, as shown in that Hubble image! (Update: this is also available at Hubblesite.org). Astronomers looked at the cluster, and very carefully mapped the distortions of background galaxies by the gravity of the cluster. What they found, after applying some fiendish math and physics to the observations, was that ghost ring of dark matter. Mind you, the image is not directly of the DM itself, but is a map of its location using those gravitational distortions. Here’s what the cluster looks like in just visible light:

If you look carefully at it (or grab a higher-res version) you can see blue arcs of light all around it. Those are images of more distant galaxies distorted by the cluster’s gravity. It’s distortions similar (but weaker) than those that astronomers use to map to the DM.

This ring of dark matter is totally cool. When I first heard about it a few days ago, my first thought was, "Hmm, must have been some sort of collision between clusters to do that." Since DM doesn’t interact with normal matter except through gravity, I knew that there is no way for matter to sculpt the DM through the usual methods (pressure, winds, things like that which give gas clouds such gorgeous shapes). But sometimes, when a small galaxy collides with a big one, the gravitational interaction can totally whip the big galaxy into a frenzy, leaving it with a ring shape. My favorite example of this is Hoag’s object:

That’s a single galaxy, though (if it were at the cluster distance, it would be just one of the dots in the cluster image). The DM ring around the cluster is far, far larger– it’s something like 2.6 million light years across! For comparison, our own Milky Way Galaxy is about 100,000 light years across. The nearest big spiral galaxy to us is over 2 million light years away, so that ring is BIG. Sometime in the past, maybe one or two billion years ago, the cluster suffered a mighty collision with another cluster, and their mutual gravitational dance puffed out the DM halo into that ring shape (you can see a diagram of this on the European Hubble website).

Interestingly, the astronomers who discovered the ring did some research and discovered a paper claiming that the cluster did in fact have a collision with another cluster: it appears that there are two separate groupings of galaxies in the cluster, which implies a collision. Evidently, we are seeing this event along our line of sight; it’s as if the colliding cluster was aimed right at us (or, I suppose, directly away from us). From the side, the ring would look more rectangular, probably, like a barrel or a life preserver seen from the side. It just so happens that our location gives this event its dramatic appearance.

This ring will prove important to astronomers for many reasons. For one, it gives us insight on how dark matter can be shaped by normal matter. We don’t understand the nature of DM very well at all, so anything like this can only be helpful in honing the theories. For another, this is a bright, dense, well-observed cluster, so we can learn quite a bit about it. The more we understand the cluster, the less we have to guess about its DM halo. For a third, this is the first time a halo of DM has been seen to be so differently shaped from the gas and other mass in the cluster. It can be studied separately from the normal matter, making that task in some ways easier.

And the best thing about it? It’s unexpected! Surprise! It’s always nice in science when things go your way, and predictions pan out. But it’s even better when you process the data, and a big fat bogie like this is sitting in the middle of it. That means there’s more to learn, more to know, more to understand. And that’s the very essence of science!

Blog carnivals are collections of the best blog posts across various blogs, all put into one cozy spot to make them easy to read. A new one is the Space Carnival, and on May 17 it’ll be hosted at Universe Today, one of my favoritest places on the web. If you have something you’ve written about space, or know of another blog that had a good spacey entry, send it to Fraser. The deadline is Wednesday night!

So I’m sitting at home today doing some work on my laptop and feeling decadent because I have the TV on as well. I decide to flip through the channels.

Home Shopping. click Infomercial. click Pat Robertson. click Same infomercial, different channel. click Poker. click Baseball. click Golf. click Infomercial. click Star Trek.

Win! Classic Trek! And it’s "Tomorrow is Yesterday", a good one. The Enterprise is thrown back in time to the 1960s, and they accidentally beam aboard an Air Force pilot, and antics ensue.

At the end, to get back to the future, they have to warp to the Sun, use its "magnetic field" to pull them in, and then that will somehow throw them first back in time a little way, and then forward back to their present.

OK.

So I’m watching, and I realize that this is one of the upgraded, refurbished Treks. They digitally remastered and cleaned up the old films, and added new computerized effects. Sometimes it’s good, and sometimes it’s not so good. In this episode, I got a chuckle out of seeing that they used special effects to make the ship’s chronometer be more digital looking, instead of the silly rotating tumblers they used to have back in the 1960s.

But then there was a "what-the-heck?" moment. As they warp past the Sun, they used a lot of the new effects, which looked OK. You see the Enterprise approach the Sun, and then move off to the right side of the Sun as it starts to warp around. The ship banks left, to port.

Now, I can forgive the idea that you don’t need to bank in space (no air, so nothing to bank against). I’m used to it. Plus, they had to put it in: in the original footage, we see the crew suddenly lean to one side when Sulu throws the switch.

But there was one thing the effects guys maybe should have thought through first. We see the ship banking to the left, to port, since it’s on the right side of the Sun. But in the original footage, everybody leans toward port!

Oops. If they bank to port, the crew would lean to the right, to starboard. Remember now, in 2006 someone went in and added that warp effect. And they screwed it up: the ship should have gone to the left side of the Sun, and the ship should have banked to starboard. Then the crew leaning to port would make sense.

I know, there are a million other things to nitpick on the show, but I give the original show a pass on a lot of them. In this case, some computer guys put the new effects long after the fact. They should have paid attention! They should be stripped of their Trek geek badges, too.

But it was still cool to see the old shows all spiffied up and pretty. Kirk rocks.

Update (May 13): I love my commenters! The meteorite has been found; in fact, it appears it was found well before I posted this entry. I didn’t find any info before I posted, but maybe my Google mojo had abandoned me. Anyway, this is good news, in a place that could really use some.

My in-laws live in Kansas, but I’ve never been to Greensburg (even though it’s about an hour from their house). Now if I go it’ll be different: it’s the town that was just literally destroyed by a tornado.

If there were any reason I’d go, it would have been to see their Pallasite meteorite, my favorite kind. They had a huge one that was found there, and in fact several have been found nearby in recent times. They have an ugly exterior, like slag, but when you cut them open they’re spectacular. They have translucent greenish-yellow olivine crystals lodged in an iron matrix, and if you cut them into thin slices and hold them up to the light, they are spectacular.

I just heard that the meteorite was lost in the tornado as well.

I’m not nearly as sad about that as I am over everything else that happened to those poor folks there, of course. I was slack-jawed looking at images from the town. That meteorite was the town’s prized possession, and it’s gone too. Man, that is an incredible bummer.

I have to add– when we’d drive through Kansas, we’d see signs for Greensburg, and they’d say that it was the home of the Pallasite meteorite and the world’s largest hand-dug well. We’d have to laugh, because a well seems like a silly thing to promote. Then, a long time later, I actually saw a pamphlet about the well. Wow. It really is big. It’s not the kind of thing I’d like to go visit, but then I can imagine a lot of people would see the meteorite and think it’s not a big deal because it’s just a rock. Different strokes. But I’m just saying — that’s a big well.

I imagine it’s still there. I also imagine they’ll find the meteorite, eventually. It’s about a meter across, and it’s almost solid iron, so it’s not likely to get too damaged (though I’d hate to see anything it might have hit at 400 kph inside that tornado). I hope they do. It sounds silly, maybe, but I bet if they find it it’ll cheer the town up a lot.

Tip of the Whipple shield to Thoughts from Kansas.

Heh heh heh. I love it when the bad guys get a little of their own back.

Noted fraud Uri Geller, who made his fortune in the 70s claiming he could bend spoons with his mind (I do it the same way Uri does — my mind says "Bend!", and then my fingers bend the spoon), has a notorious habit of suing everyone who says bad things about him. He and superskeptic James Randi have been at each others’ throats for decades (Randi tends to win).

Anyway, the Rational Response Squad, a group of skeptics,Electronic Freedom Foundation is suing Geller (on behalf of the Rational Response Squad)! The RRS put some vids on YouTube showing how Geller is a fraud. Geller demanded YouTube take the clips down, saying he owns the rights.

Oops. No he doesn’t. So the RRS EFF is suing him.

I will sit back and enjoy the developments of this situation with great amusement and schadenfreude. Geller is a bad man, who does everything he can to intimidate his critics, so I am lovin’ this. Stay tuned to the Rational Response Squad for more info.

Tip o’ the goggles to Rebecca. Note: I mistakenly said originally that the RRS was suing, but it’s the EFF on their behalf. Thanks to commenter David Vanderschel for pointing this out.

Update 2: an article in the news said a fund has been set up for Ms. Malloy by Wells Fargo bank. As I write this it’s evening and they are closed, but I’ll check tomorrow to see if there is a way to donate to this fund online. I didn’t see anything at their website.

Update (Monday, May 14): This blog entry has incited quite a reaction. I expected some, given that I am poking at what is essentially a religious viewpoint about miracles, and a superstitious viewpoint on luck. However, somewhere along the line while writing it I lost track of my ultimate goal which was to simply point out how we tend to ascribe causes to random events, and how this leads to uncritical thinking. Where I blew it was jumping right into this discussion before acknowledging where it comes from: a real human who has suffered a horrible accident. I know it’s hard to tell tone from words, but I am being very honest when I say I wish nothing but good for Ms. Malloy on her road to recovery, and I apologize for any grief she’s had about this. While I disagree with many (if not most) of the negative comments about the meat of my claim, what I cannot disagree with is that the tone of this entry is more snarky than it should have been. I let my irritation get the better of me stylistically, and again I apologize. I hope that my extended comment on this entry clears that up. Given the number of comments and the back-and-forth of them, I will leave this entry intact as I wrote it (except for the insertion about the chiropractor); but it can also serve as a reminder to any of us who blog, comment, or just plain discuss topics, that many times there is a reality behind the discussion, and people who are affected. Some of the comments below cross well over the line as well, so I hope that everyone involved here has learned a lesson.

Man, I get tired of this kind of stuff:

A car crash in Nebraska on Jan. 25 threw Malloy up against the vehicle’s dashboard. In the process, her skull became separated from her spine. The clinical term for her condition is called internal decapitation.

That’s the gist of the article: a woman survives a bad injury that in most cases would kill the victim. But the amount of bad thinking that continues from there is astonishing. Let’s look:

Miracles do happen. That’s what doctors said about 30-year-old Shannon Malloy.

Ah yes, a miracle. It has nothing to do with pure statistics and probability. Or the fact that medical science has advanced enough to save someone’s life.

Dr. Gary Ghiselli, a chiropractor an orthopedic spine surgeon at the Denver Spine Center, said Malloy’s will to survive is what saved her.

A chiropractor said it was her will. Right. I suppose someone involved with what is at the very best a borderline quack field would say it was her will, and not, say, probability and medical science. Note added Monday, May 14: The original news article said that Dr. Ghiselli was a chiropractor, but that has been amended in that article to indicate that Dr. Ghiselli is an orthopedic spine surgeon — a profession that I can say with some confidence and personal experience is a lot more trustworthy, reliable, and scientific than chiropractic.

“I had a fractured skull, swollen brain stem, bleeding in my brain, GI tube in my stomach, can’t swallow, and nerve damage in my eyes (because they cross),” said Malloy.

Doctors are working on that but she has been lucky enough to get the halo removed.

I know I shouldn’t get upset when people talk about luck, but it still irks me. Luck is probability taken personally, as the saying goes. She wasn’t lucky to get the halo removed, it’s just the way things worked out. I have actually specially worked on not using the word "luck" anymore. It’s just another accepted notion that’s incorrect, and I don’t want to promote it, even colloquially.

“Oh my God, it’s a miracle,” said Malloy.

I guess then it was also a miracle that God made the terrible, horrifying accident to happen in the first place, too. You can’t pick and choose which random events to ascribe to God, folks. If He throws the dice for one, He throws the dice for all.

“It’s a miracle that she was able to survive from the actual accident. It’s a miracle that she’s made the progress that she’s made,” said Ghiselli [the chiropractor].

See above. I suppose then it’s a miracle her skull was severed from her spine, she sustained nerve damage, and she cannot see well or swallow properly.

That’s some miracle. Tell you what: I’ll take my chances on probability.

Fraser Cain, my buddy who runs the Universe Today website and co-admins the Bad Astronomy and Universe Today forum, wrote up a great blog entry about how to maximize your lifespan if you fall into a black hole. Don’t get me wrong– you’re still screwed, but you might get a femtosecond or two longer to live if you heed his advice.

And if you like what he wrote, Digg it!