Blogs / Bad Astronomy

I’ve been getting a zillion emails about this, and the video has 1.7 million views, so you’ve statistically probably already seen it, but just in case…

Jamie Hyneman and my close personal friend™ Adam Savage indulge in a little demo of parallel versus serial processing.

Awesome. This is a condensed version of the whole presentation, which is totally worth watching. Here’s Part 1 (which ends just before the Big Event) and Part 2, which picks right up where the first part left off.

Having a mancrush on Wil Wheaton has its advantages. I won’t enumerate them — read his blog, and then you’re on your own — but one is that he has good taste in writers, and that rubs off. Every now and again he’ll mention John Scalzi, a science fiction writer and blogger. It got to the point where I figured, why not? So I clicked the link to Scalzi’s blog. I’ve never looked back. Scalzi is my kind of people.

Scalzi wrote the Old Man’s War series. His blog, Whatever, just won the Hugo, the Oscar of scifi.
He writes funny short stories. Scalzi is semi-evil (in a good way), and engaging, and all-around cool.

He also taped bacon to his cat. Yes, that John Scalzi. He’s an internet god.

So when I heard he was coming to DragonCon, I was pretty excited. I figured I might get a chance to actually meet him IRL, though honestly, the odds were not 100%. The con is vast, dark, and deep, and it can be hard to actually meet up.

Still and all, it helps to be prepared. Richard and A were visiting me in Boulder before the con, and then all three of us were to wing to Atlanta for the fete. While they were here in Boulder, we visited the wonderful pedestrian mall. We cavorted and enjoyed ourselves, and A made it clear she wanted to visit the candy store. I’m glad we did, because they had awesome gelatto, but also because, purely by accident, I saw they had a bacon-shaped tin of bacon-flavored jelly beans.

Yes. I bought them in anticipation of being Scalded.

And also, just in case, I kept them with me in my dorky backpack for the whole con, just in hope of running into him.

So come Saturday at the con, and by happenstance I am between panels, talks, gigs, scheduled appearances, and needed attendances. A, Richard, and I are still hanging (this time with Pamela, too), and decide to hit one of the dealer rooms. You can guess where this is going. We pause for a moment to gather our breath between all the booths selling toys, trinkets, fake weapons, and swag. I look around, and realize I am standing literally in front of the table where one John Scalzi was signing copies of his book.

Awesome.

I look at him for a second in shock, then gather my wits enough to yell "Scalzi!" He looks up, takes a moment, and yells "Phil!"

<Sniff>. It was beautiful. I gave him the beans, and he laughed (they were destined to be part of a larger and more interesting story that Scalzi — perhaps wisely — has yet to divulge in full). We shot some pictures. We made faces. And then I left.

Sadly, that was it for my Scalzi encounter, but I assume in the future there will be more. How can I resist a man like this?

Michael Shermer, head of the Skeptics Society, is hosting a two-day conference in Pasadena, California, called "Origins: The Big Questions". It’s all about the origin of man, the Universe, and everything.

Sadly, I can’t go (it’s October 3-4, and I am frightfully busy then) but oh, how I wish I could. My friend Sean Carroll (from Cosmic Variance) will be speaking, and he’s very good. Also, Hugh Ross will be speaking. He’s an old-Earth creationist. Yes, you read that right: he thinks the Bible should be massaged and twisted and strangled so that it supports the notion that it’s still inerrant, but says the Earth is old.

Heh.

So that would be a fun talk to listen to as well. And to top it all off, they have Mr. Deity speaking! OMMD^*! I would so dearly love to hear that. The Mr. Deity videos are really, really funny.

This looks to be a great conference, so I encourage my minions to attend. If anyone goes, let us all know in the comments!

^*MD = Mr. Deity, of course.

I finally have an intertoob connection here at DragonCon, but not a whole lot of time. In fact, that seems to be a theme here: get up early, do tons of stuff, go to a party until 3:00 a.m., rinse lather repeat.

I can’t complain; I’m having a tremendous time. I’ve been hanging with friends (including Skepchicks, woohoo!), listening to great panel discussions on space and skepticism, been on a few myself, and generally soaking up the geeky goodness.

But of all of this, my fave part is the fans. And the costumes! DC is known for having more people in costumes per cubic meter than any other con, and I’m loving it. I ran into these guys last night, and over the past coupla days I’ve seen a half dozen more Doctors. And demons, cosplayers, vinyl-clad posers, giant thingamabobs (actually, several of them), and even a Cylon. I don’t have time to post any pix now, but I will when I get home (Tuesday).

But there’s still lots to do; I’m going to see a preliminary test for Randi’s Million Dollar Challenge in a few minutes, and later tonight my bud Kevin Grazier and I are on a panel about British Sci Fi (I can talk Doctor Who and people will listen and ask for more! Heaven!). Also, my friend Mykal brought me Blenheim’s ginger ale, which I am drinking as I write this. I simply cannot ask for anything more.

Well, that’s not true… I’m hoping to get James Hong to sign my David Lo Pan t-shirt. Indeed!

A while back, I wrote about why there are no green stars in the sky (you should read that post first; some of the concepts below are explained there).

But that’s not to say there are no green objects in space. There are!

Low-density gas clouds, like NGC 6826 (which I studied for my Masters degree, incidentally), emit light in a very different way than stars do; they aren’t blackbodies at all. They are more like fluorescent lights, giving off lights at very specific colors, and not continuously across the spectrum.

If the cosmic gas is hot, and contains oxygen, the nebula can strongly emit light at about 500 nanometers, smack in the green part of the spectrum. They also emit some red and other colors, but they don’t emit across the entire spectrum like stars do. These objects do in fact look very green through the telescope, but remember, they’re not stars!

The planet Uranus looks green too, but that’s because its upper atmosphere has lots of methane, which absorbs red light. Again, it’s not a star so it doesn’t count.

Now, I do have to say, there is a way for some stars to kinda sorta look green. We sense colors not just on an absolute scale, but also by comparison as well. An object that looks one shade of red by itself will look a different shade if you put it next to a yellow object. Your eyes and brain together can be fooled this way.

Almach is multiple star system in Andromeda (though to the eye it looks like just one star), and its components do just this. The brightest star is an orange giant, a star like the Sun that’s dying. It’s cooler than the Sun, and so looks orange to the eye. The other three stars comprising the Almach system are white dwarfs, dead stars that glow due to their leftover heat. Two of them are barely separable by telescope, and the third orbits one so closely it’s impossible to see. But the combined light of these three stars is whitish… but when you look at it through a telescope, with the orange star visible as well, the trinary takes on an emerald green glow! It’s not real, in that it’s an illusion, but it does still look green. Interestingly, in all the images I found, it looks bluish; maybe the camera is not as easily fooled as our brains. Other examples of multiple stars like this can be found, too.

But is there a star that’s intrinsically green? Zubeneschamali is the second brightest star in the constellation of Libra. It’s somewhat hotter than the Sun, and some people claim it looks green to them, while other say it looks white. It’s unclear why; some people’s sensitivities are different, but it might also have to due with the star itself: Zubeneschamali is a young star and a rapid rotator, which might affect its colors (the emitted light from a star is not really a blackbody, and its youth and rotation might have some influence on its emitted colors).

So maybe, maybe, there is one intrinsically green star, but even then its controversial.

There are several lessons here. One is that stars really can’t be intrinsically green; they need to be seen against a contrasting color to look green, and even then it’s just a trick. Also, there are green objects in space, but they are very different than stars (gas clouds and planets). And finally, the color we see from an object depends on how that object emits light, which can be just as important as the light emitted itself.

I’ll be on the Coast to Coast AM radio show tonight from 11:00 – midnight Mountain time (05:00 – 06:00 UTC)! They just called and needed someone to fill in; it’s been a while since I’ve been on so this’ll be nice. The host, George Noory, and I like each other, and he’s an easy guy to talk to. We disagree on a few issues, as you might expect, but we still respect each other and get a kick out of chatting. I’ll probably be talking about the Mythbusters, of course, the news from Hubble today about dark matter (I haven’t had a chance to write it up, but the ever-diligent Universe Today has the goods) and probably plug Dragon*Con, which I’ll be attending this weekend (and I’ll have a post up about that Thursday).

You can find the affiliate stations that carry C2C at their site, linked above. Many stations stream it (I like CFUN) so you can listen no matter where you are.

The day has dawned, the clock has rung, the time has come, calloo callay!

Tonight, the Mythbusters take on the Moon Hoax (check your local listings)! OK, for you newbies, read Parts 1 – 4 (here, here, here, and here). That’ll catch you up on the history.

I was able to get an advance copy of the show — I have powers beyond those of mortal men… or maybe I’m just on a Discovery Channel mailing list for the show, and I asked for a DVD when they said they’d send them to journalists — and let me say, it’s really good. One of their best, in fact! I can’t reveal the results of their tests, but I will say that however each of the tests did in fact turn out, I could see why they came to the conclusion of "busted, confirmed, or plausible" for each.

Having helped them with some of the tests, it was very cool to see the results on screen. They tackle several of the biggies, including why shadows on the Moon appear to be non-parallel. To my great surprise, they came to a somewhat different conclusion than I usually claim for this. I will have to amend my own discussion of this when I give my Moon Hoax talk. Seriously. Nice work on the MB team’s part!

Oddly, one thing that stood out for me was the pronunciation on the show of the word "regolith" (the powdery surface dust on the Moon). I have always said rehg-o-lith, but they all said reeg-o-lith. Now, they talked to NASA folks who must know how to pronounce the word, so you’d think that was right. The thing is, I’ve talked to experts as well, and the ones I know say it the way I do! So now I’ll have to dig into this (haha! Dig! It’s regolith!) a little deeper. Interesting.

One big laugh was that Adam has his own space suit. It was a wedding gift from the MB team. He then modded it to make it more accurate, including a wrist-mounted booklet of instructions just like the Moonwalkers had. But in one part, I noticed that while he put red commander’s stripes on the arms and legs, he left the stripe off the helmet. I was gonna take him to task on this, and then found out that the helmet stripe was only added after Apollo 13. Knowing Adam as a close personal friend^*, I’m sure he modded the suit to be an Apollo 11 one. The funny thing to me is that Neil Armstrong was the commander of Apollo 11, and took all the pictures of the lunar surface during their short stay in Apollo 11, so all the shots show Buzz Aldrin, the astronaut without the stripes. Edited to add: As has been pointed out in the comments below and personally to me via email, the stripes weren’t added at all until Apollo 13, so in fact Adam’s suit is incorrect if he’s trying to make it an Apollo 11 simulacrum. I will very much tease him about this when I get the chance.

OK, so it’s not all love and roses for the MB guys: I do have one minor complaint, and it’s about their test of the flag-waving in a vacuum. They seemed to focus on the flag continuing to move after an astronaut stops manipulating the flagpole into the lunar surface, whereas the Hoax goofballs always seem to be complaining that the flag is moving at all, even when the astronaut still had his hands on the flagpole. When I show clips of the flag waving, I make a big point that the corner appears to flap up very high on the Moon, and that’s due to no air and lower gravity. On the Earth, air resistance makes the flag flap rather lackadaisically, and that shows the astronauts were in a low-gravity vacuum environment. Hmmm, where would the nearest low gravity vacuum be? Oh, I know: the frakkin’ MOON.

The MB team also tackle the idea that NASA may have slowed down the footage of the men on the Moon to make it look like they were in lower gravity. Basically, as has been argued by me as well as my friend Jay Windley, slowing down the footage makes it look like the gravity acting on them is less, but it won’t make non-gravitational motions look right. So if an astronaut picks up a rock and drops it, the rock will fall slower, but the actions of the astronaut moving his arm is slowed as well, and that looks goofy. The Mythbusters did a fine job going through this argument and their experiment was not only well executed but Jamie made an excellent observation during that part. I won’t reveal what they found, but keep your ears open for his comment there.

I have some more notes, but I can’t really discuss them without giving away the results, so I’ll hold off. But I think that’s probably enough. You should see for yourself. If I have any real complaints about this episode, it’s that is was too packed with stuff. They should have made it a two-parter! For example, I would have loved loved loved to see how Adam made the model of the Lunar Module (over which I still lust). And there were other aspects that would have been cooler if more details had been given. But still and all, enough is there to cover the ground regolith on this hoary and hairy myth.

For those who want more, Robert Pearlman at CollectSPACE did an interview with the MB team which is now up, and there are some tidbits from me as well.

And I must leave you with this: a screen capture of the title credits for the show:

Squa-weeeee!

^*I am contractually obligated to refer to him this way.