Blogs / Bad Astronomy

Edited to add: I’m getting quite a few emails and comments stating that Greg Laden’s conclusions are pretty far off-base here. OK then, that’s why I asked for comments! I found his take on it to be interesting, certainly, but if it’s in error that’s a different situation entirely. I’ll look into this more when I can. I’m learning quite a bit about Catholicism, and I enjoy learning things. So thanks to everyone who’s taken the time to discuss this.

Y’know, when the news hit that a Vatican astronomer was amenable to the idea of aliens, I wasn’t overwhelmed. Without breaking a sweat I can think of about forty astronomers who could write a similar article, so it didn’t seem like a big deal. However, not being raised Catholic, I may have missed some import to the words, of course.

Greg Laden over at Science Blogs has a really interesting take on this that never would have occurred to me. It’s worth reading, and I’m curious to see everyone’s thoughts on this. Feel free to comment there (be polite! Thank your host! Wipe your feet before you step inside!) or here.

And he has a bonus Talosian^* picture there. Exxxxcellent.

My friend (and he’s on probation after this) Dan Durda sent me a link to The 50 Worst Album Covers. That’s a grandiose claim, but man — I’m thinking they nailed it.

Which of us truly has not been in exactly this situation?

Now I have to wonder if some are real: Number 41 is stolen from The Simpsons (Milhouse’s father sang that song, so I wonder which art is imitating the other art). And c’mon, Number 27 is just plain true. Number 46 is funny on purpose, too, so I don’t think it counts.

But the rest… yikes. Click that link at your own risk.

… and a note to my sister: recognize that weird clown thing over her shoulder in that picture?

Shhhh! No one tell PZ about this cartoon. The next thing you’ll know, he’ll be applying these principles to stellar evolution.

Tip o’ the apple cart to Dave Morton.

Well, I suppose I asked for it. I wrote a thoughtful, cited, linked, and clear post on how vaccines are unrelated to autism (as well as in an update), and got a flock of antivax nonsense in the comments in return. I’ll preface any details to say that there has been a lot of support for my post, especially from Orac, who knows a thing or two on this, and I thank everyone who replied — on either side of this issue — who did so politely and reasonably. I did get some interesting emails as well from parents of autistic children, and again I thank them and send them my best hopes and support.

But then I get email like the following (in italics below) with my comments interspersed (in normal print); it is reproduced in full but with the author’s name and email address left out to prevent a flood of mocking from people less polite than me.

WARNING: set your irony meter volume way down, lest it vaporize.

You do not have the credentials to have an opinion on this subject.

Well, I’m a trained scientist, able to read graphs and do basic statistics. I have a passing familiarity with logical processes, and how to think through an argument. I also have years of experience as a professional skeptic, you might say, in seeing through fallacious arguments.

I’ll note that the emailer did not give their credentials on understanding the subject, either.

Your flippant, self-promoting, and arrogant rant shows what you are all about — attention.

Oh, attention doesn’t hurt, especially when I think my message — like this one — is of critical importance. But that argument is wrong anyway; where does it actually deal with the content of my message? Oh, right, in this next silly statement:

Removing a link between thimerosal and vaccines does not even prove your hypothesis. This very bad science.

Actually, I am debunking someone else’s argument, and that is that thimerosal causes autism, or that vaccines in general do. The case against this argument, I think, has been made very well by the overwhelming totality of scientific study on the topic.

Your hypothesis: “Vaccines do not cause autism.” Really!? Can you site [sic] a study that shows a non-vaccinated child population, instead of a timerosal [sic]-free population? Didn’t think so.

Actually, the links I provided in the post do just that. Only part of that was about thimerosal; the graph I showed. There are lots of other studies.

Why don’t you go and do a little research instead of spewing anecdotal evidence and your very misguided opinions out to the internet.

The author of the email has grossly confused the difference between anecdotes and data. Maybe the email author is unfamiliar with the concept of scientific studies, like the one I linked to, and the other links that cite many other studies. I’m not the one with anecdotal stories; the antivaxxers are.

People like you make me sick.

BANG!

Nuts. Now I have to buy yet another irony meter.

Hello? It’s the antivaxxers literally making people sick. That’s the whole point. If we don’t vaccinate, then we are dooming our children to suffer through pertussis, measles, mumps, chicken pox, (damage from) HPV, and a host of other ailments, some of which are fatal, but most of which have dire public health consequences.

So there you go, folks. That’s the sort of irrational attitude we’re dealing with here. Bear that in mind when you are deciding how to couch your words with the anti-vaccination group. People with autistic kids certainly deserve our support, and our sympathy. But only up to when they advocate a public health disaster. I will still be sympathetic about their personal trouble, but I will not back down when they promote anti-science and try to sentence millions of children to suffer terrible ailments and perhaps even death.

I’m getting approximately eleventy bazillion emails about two news items: one is that the Vatican is welcoming our new alien overlords (if they exist), and that the UK has released lots of UFO files.

On the first, I’m not sure what to think. Given that it took the Vatican four centuries to fess up that just maybe possibly Galileo was right, I’m not so sure I care what they think about aliens. On the other hand, this is in direct disagreement with the oh-so-logical proclamations of creationists (in a nutshell — haha — special creation precludes life elsewhere), so maybe this will provide some fun schadenfreude.

As far as the UFO thingy goes, I’d go through the files and look for unexplained cases, but golly, my toenails need cleaning right now.

Seriously, my thoughts on this are on record. I’d actually be interested in seeing some of the more odd UFO cases, but I don’t want to plow through hundreds of cow mutilation stories at the moment. If anyone finds any good ones, link to ‘em in the comments.

The latest edition of Tangled Bank — a science blog carnival — is up, and I get schooled, apparently. It’s not my fault that every space agency seems to misplace Mars probes…

If you’re wondering what all the buzz has been about the past few days over a NASA discovery, then wait no longer. No, it’s not aliens or an incoming asteroid. Instead, it’s still very cool: astronomers have found the youngest supernova in the Milky Way.

First, before I explain, here’s the photo of the newest galactic family member:

It kind of looks like a baby head swaddled in a blanket. Or a really bad drawing of Caesar. Anyway, seriously, this is a big deal. Why?

When a star like the Sun dies, it blows off a lot of its outer layers, leaving behind a dense hot object called a white dwarf (FYI, I have a more detailed description of all this here). If the star is binary — it has a companion — then the immense gravity of the white dwarf can draw material off its mate, and that matter will pile up on the surface of the dwarf. If enough piles up at just the right rate, it can ignite in a thermonuclear fire. This sets off a chain reaction, and the entire star self-destructs. This creates an immense amount of energy — as much energy is released every second as the Sun emits for billions of years — and an octillion tons of gas is launched violently into space at a large fraction of the speed of light.

The event is so titanic that it can be seen clear across the Universe, and of course you don’t want one to happen too close^*. But somewhat close is good: we can study them better.

We know how many stars like this there are in our galaxy (as well as massive stars which can also explode, although using a different mechanism), and we know roughly how long they live, so we should be able to predict how often one should go off. The answer is, about three per century, more or less.

But observationally, it’s been more less than more. That is, the last one we know of that blew up in the galaxy was over 400 years ago. That’s been a major pain for astronomers; statistically speaking, it’s a little weird that we haven’t seen one since the 1600s.

But that’s changed. After searching for literally decades, astronomers have found a supernova in our galaxy! It’s official name is G1.9+0.3, which doesn’t exactly make your heart sing, I know. But it’s very cool. It’s a remnant, the expanding gaseous debris from a supernova blast. It’s located very near the center of the galaxy, about 28,000 light years away, and it’s only at most about 140 years old.

The false-color image above shows the remnant as seen by the orbiting Chandra X-Ray Observatory, and the ground-based Very Large (radio) Array in New Mexico. To give you a sense of scale, the object is about 13 light years across, or 80 trillion miles end-to-end. The orange crinkly stuff is extremely hot — millions of degrees hot — X-ray emitting gas, generated by vast magnetic fields in the gas. The bluer material is smoother radio wave emission also dominated by magnetic forces.

Together, they paint an interesting picture of this explosion. For one thing, it looks like a ring, or a smoke bubble. That’s a clear sign that it’s actually a shell of material, and not a solid sphere. A filled sphere of gas would be brightest in the middle and fainter near the edges (because we’re seeing more bright material when we look through the center of a sphere as opposed to near the edge), but a shell has the opposite behavior.

For another, it’s asymmetric: the gas is not expanding in a perfect sphere. Either it’s slamming into gas that existed outside the star before it blew up, or the explosion wasn’t perfectly spherical. That tells astronomers quite a bit about the physics of the explosion mechanism.

How do we know it’s young? Ah, an excellent question! I love this part: we’ve seen this sucker expand!

Here are two radio images of the remnant taken 23 years apart:

See how it’s gotten bigger over time? By measuring that expansion and knowing the time elapsed between the two pictures, we can extrapolate backwards to see how old the object is. If you do the math, all that gas was in one point about 140 +/- 30 years ago. That’s actually an upper limit to the age: it may have been less than that, if the expansion is slowing over time due to the material slamming into gas floating in space. That’s likely; that region of the galaxy is pretty thick with dust and gas.

In other words, this thing went off around the time of the American Civil War.

So that’s how we know it’s the youngest we’ve ever seen. But there’s more! We know the distance to the remnant as well. The amount of dust and gas between us and it can be measured and compared to known maps of the galaxy, kind of like knowing how far away distant mountains are by the amount of haziness you see between you and them. Combining the distance with the expansion measured means we can get a real velocity for the gas, and it’s a whopper: 14,000 kilometers per second, or 5% the speed of light! That’s fast. The amount of energy released in a supernova is numbing.

So you may also ask, why didn’t anyone see this thing when it went off? All things being equal, at that distance it should have been as bright as Venus in our skies, visible even in daylight! But all things are not equal: all the gas and dust between us and it absorb visible light, making this object almost totally invisible. It might have been visible to someone using a good telescope a century or more ago when the explosion took place, but that astronomer would have had to have been looking at just the right spot, and noticed a very faint star that wasn’t there a few weeks before — and this object sits in a part of the sky loaded with faint stars. It would be like noticing a new grain of sand on the beach. Unlikely, and in fact no one did notice.

It can be seen now because we have more advanced instruments these days. X-rays and radio waves are not as affected by intervening glop in the galaxy, and pass right on through. That’s why we can see it at all; even in big optical telescopes G1.9+0.3 is totally invisible.

So there you go. This object will be heavily studied now, I’m sure, because it’s the youngest such explosion we can see up close. It may help us understand how white dwarfs explode, and what the environment is like near the center of the galaxy, and how gas behaves when it violently expands in such a place.

And, well, it’s just cool. It’s been a mystery for a long time why we haven’t seen any young remnants — we expect there to be 60 of them younger than 2000 years, but only 10 are known — and now that we’ve seen this one we know they’re out there, but really just a pain to detect. You can bet that astronomers will look even harder for more of them now that we know they exist.