Blogs / Bad Astronomy

Via the Freakonomics blog (yes, the same as the book, which is a really interesting read), comes this astronomy test for 7th graders (link is to a MS Word document).

Take a look. The questions are not ridiculously hard — though they aren’t trivial — but somehow the terse, harsh phrasing of them makes the test seem harder than it is. I suspect that most Americans would do abysmally on it. As usual with such tests, you need to read the instructions carefully so you know precisely what they are asking.

I had to laugh at this question though:

A display of arcs, lights, and streamers in the polar regions is called the auroras. The light is produced as charged particles come in contact with the Earth’s magnetic field. These charged particles come from

A. star particles in outer space.
B. the solar wind streaming from the sun.
C. the hot core of the sun.
D. fragments of meteoroids burning as they enter Earth’s atmosphere.

Besides the horrific grammar error in the first line, the question is technically wrong. The light is produced when the particles stream into the Earth’s atmosphere and ionize it. The particles are accelerated by the Earth’s magnetic field, so radiation is emitted, but it’s in the radio wavelengths. The visible light isn’t emitted until they slam into the air.

Tip o’ the beanie to Joshua Zucker for the link to the Freakonomics blog.

Which of these galaxies is farther away? Or are they at the same distance?

For a long time, astronomers thought they were at the same distance. The upper galaxy — NGC 5011 B — is your standard edge-on disk galaxy, about which a lot is known. It is obviously part of the Centaurus cluster of galaxies, located about 150 million light years away.

The lower one — NGC 5011 C — is, well, a smear. If it’s also at that distance, that would make a giant galaxy, like our Milky Way, and we have never seen any big galaxy shaped like it before. Is this a new breed of galaxy?

Nope. It’s a familiar one, and we’re suffering from a cosmic coincidence. Astronomers were able to determine the distance to NGC 5011 C, and found it was at a mere 13 million light years– a skip and jump away from us, relatively speaking. This makes it a dwarf galaxy, and we see lots of those. In fact, the brightness and size of the galaxy are just right for a dwarf at that distance.

Clearly, the two galaxies are not physically associated; they just happen to line up in the sky and be about the same apparent size. The spiral is far bigger in reality, more than 10 times as big. It’s a bit like the Moon and Sun in the sky: The Sun is 400 times the physical size of the Moon, but it’s also 400 times farther away, making them both about the same apparent size to the eye.

So astronomers have closed the book on this particular mystery, a book that we shouldn’t judge too strictly by its cover. Sometimes it pays to read between the lines.

I recently wrote about Richard Branson’s Virgin Galactic sub-orbital rocket plane, and described it somewhat romantically (both literally and figuratively). But how realistic is this dream of low-space tourism?

Jeff Bell’s answer is: not very. He seems very cynical, and having read some of his past essays, I find he does come down on the dour side. But that doesn’t negate his basic point: rocketplanes have a scary record, and the environment in which these vehicles are being developed is not going to guarantee their safety; Bell argues just the opposite will happen. I think that some of his points may be at the very least debatable; new materials and equipment that have been developed in recent years may make a big difference in safety margins.

But I am no expert in this field, and we’re still in the stage where both sides are hammering out their arguments. I’ll continue to read about this with interest!

Yikes! I meant to post this the other day. Sorry about the delay.

Well, Viacom/Paramount or whatever they call themselves these days has made it official: Star Trek XI is a real project, and it really is a prequel, and it really will have Kirk/Spock/McCoy in the early days, and it really will be directed by J J Abrams, despite repeated earlier denials and all the ridiculous stuff Hollywood does when they don’t want news to break early.

So who will star? The rumors are flying, but my favorite is: Matt Damon, Adrian Brody, and Gary Sinise as K/S/M, respectively. That may be a joke, but I have to say it’s a really good call, and in fact I wouldn’t have any problems seeing these three as The Three. I really like Matt Damon, who is a phenomenal and very natural actor. He’d be great as Kirk.

And can I dare hope? Could it revitalize Trek in the way Enterprise didn’t quite manage (despite a phenomenal comeback in the fourth season)?

Yes, I’m a geek. But it’s Trek. And it’s coming back!

W00t!

I leave you with this. The Shatner.