In the Index to Creationist Claims, there is an entry to an old argument from Walt Brown:
Claim CE302:
The sun has 99 percent of the mass of the solar system, but less than 1 percent of the angular momentum. It is spinning too slowly to have formed naturally.
Source:
Brown, Walt, 1995. In the Beginning: Compelling evidence for creation and the Flood. Phoenix, AZ: Center for Scientific Creation, p. 19.
Response:
Among solar-type stars, there is a strong correlation between age and rotation rate; the younger stars spin more rapidly (Baliunas et al. 1995). This implies some kind of braking mechanism that slows a star's rotation. A likely candidate is an interaction between the star's magnetic field and its solar wind (Parker 1965).
So we have a theoretical explanation, braking, and a correlation. Now Phil Plait discusses new evidence supporting the braking model : observations of stars with and without accretion disks show that all that material does seem to slow the rotation of the star down. There are some nice animations, too — the magnetic field of the star is like a big paddle-wheel moving through muck. Very cool.
This is why biologists keep the astronomers around — so they can answer the occasional off the wall questions we get from creationists about stars. And angular momentum. And magnetic fields. You know, all that physics stuff.
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What I don't understand is why anyone (even someone who already believes in God for other reasons) thinks "God created it that way" is a reasonable conclusion to "We don't understand how this bit of the universe got to be the way it is". It's no different than saying "It happened by magic" -- an answer that satisfies no one over six years old.
Always nice to see one more creationist canard definitively debunked. The list of creationist claims that even have a faint possibility of being right continues to shrink...
Side note: "concretion disk"? No such thing. Were I in a snarky mood I might seek to use that as the basis for an elaborate biter-bit scenario involving certain individuals' tendency to use even inconsequential errors as grounds to dismiss another individual's entire argument.
But I'm not in a snarky mood, so I'll simply point out that the term you were obviously reaching for, and almost got, was accretion disk.
Nice
In truth, a very large number of the "questions" regarding evolution are not about biology. The laws of thermodynamics, nuclear decay, superimposition, erosion, fossilization, extraterrestrial dust accretion, age position and orbit of the sun, of the moon, and this bit about the sun you've pointe out; polonium halos, and so on.
This is why biologists keep the astronomers around
Well, that and the hope that sooner or later an astronomer will come along and ask me about the aliens she's found.
(yes, the astronomer in this case will be female - sorry, Phil - because this is my geek fantasy and I like smart women who can do math better than I can).
Love the blog PZ. One small point, it's "accretion disks" not "concretion disks" Glad us astronomers get in on the fun of creationist nuts too! You biologists seem to get most of the action though.
I was thinking that science having to defend against anti-evolution is more like the Hall of Justice... everyone has special skills that come in handy at different times against different villains, pretty much everyone is on equal footing, but there are more "senior" and "regular" members that end up doing the majority of the heavy lifting when it comes to going on the defensive against the no-good evil-doers Bible believers.
Great way to learn about angular momentum (and waste office time).
Get a spinable office chair hold some weights and get someone to spin you, if you now extend your arms out to your sides you'll slow down because the mass of the weights is now further away from the centre and so to conserve angular momentum the rotating body (you) has to slow. That way is more applicatble here, but the more fun way is to hold out the weights and get spun, because then when you pull in the distance is reduced and, to conserve angular momentum, you speed up.
disclaimer: the office of me is not liable for broken chairs random falls and smashed screens that you didn't think were that close.
Oh the spelling! and the grammar too! Please don't hurt me, I'm only a lowly grad student.
Creationists don't dare take on astronomers and phycisists because then they have to say stuff like "gravity and general relativity are just theories", or "of course god created microwave background radiation, it says so in Genisis where god said 'let there be light'" (and I might add, heavily redshifted light).
Creationist objections to, say, stellar formation basically amount to 'sure, we accept microgravity, but macrogravity is just ridiculous.'
Great news that my soon to be profession will be kept around. Even if it is just for debunking the Creationists. What do I mean, 'even it', it's probably one of the highlights of going into any science field.
Just for some additional whompage, I've been kicking the hell out of creationist stellar evolution claims on my blog in this series of posts.
The older ones are a direct refutement of an AiG article FTK is so fond of. The more recent ones are a blanket covering of the subject.
...like the Hall of Justice...
I always thought Pharyngula! and The Bad Astronomer! sounded more like super-villain names, tho.
Creationists, and more recently IDists, are more than happy to take on astronomers and physicists. Just remember that recent "Privileged Planet" brouhaha.
Astronomy may be more dangerous ground for creationists to tackle, since our view into space gives us a direct look into the past all the way back billions of years, but that doesn't mean they won't try (and, sadly, be successful at fooling millions of people).
This may or may not be an aside; I'm just not sure.
Walt Brown was the first clown I "met" (not personally, of course) in the Creationist circus. After reading his material for a day or two, I realized that he's just a crackpot. Unlike Behe, who spouts off a lot of junk I don't think he really believes, Walt Brown appears to believe everything he says.
His theories about Noah's Floods are just plain fun. Absolutely wacky.
If Behe is the village's snake-oil salesman, Brown is the village idiot.
Can't wait to meet the mayor.
I got to Pharyngula through Skeptic's Annotated Bible, still one of the best skeptic sites on the web.
This is why biologists keep the astronomers around
Isn't that also why physicists keep mathematicians around?
It's really bad to be the good guys!
I always wanted to be the robber when I was a kid.... (cops &...)
hmmmm.... maybe a correlation there? I'm now a consultant! ;)
Thanks for the link love, PZ. Biology and astronomy are the two biggest targets for creationists, obviously; how dare we say the Universe is more than 6000 years old!
I like smart women who can do math better than I can
Check out the "Nerd Porn Auteur" MP3 on this page.
You guys might also like this.
But poor PZ now has two more to kick out of their beds.
Bob
tacitus:
Case in point, Sal Cordova's recent blitherings about classical mechanics.
Sigh.
Maybe I should ask this on Phil's blog, but I see he's posting here anyway.
I don't really understand the original complaint by the creationists: Why should one expect the distribution of mass to match the distribution of angular momentum in the first place? Shouldn't the sun have a smaller fraction of the angular momentum simply because it is sitting (and was formed) at the center of the solar system? Do current models of solar system formation really predict that the sun would have initially had 98% of the angular momentum to match it's 98% of the mass?
Why don't astronomers just change their terminology to win converts among the theists?
Magnetic field = God's Grasp
Angular momentum = Divine Impetus
Accretion disk = Sacred Nimbus
Solar wind = Celestial Flatulence
I'm biologists could come up with many more.
Whoa! Plait has some pretty fierce cretinists posting over there - "Joel says, "This is the Institute for Creation Research. They have peer review from Atheist groups. Do you know what those Atheist groups think? They think ICR is interested in honest science...."
News to me.....
Don't forget geology! Let us not forget that modern "scientific" creationism started with attacking geology rather than biology or astronomy. in the 1920s George McCready Price thought that if he could explain the geologic record by reference to Noah's flood he could undercut evolution without entering into biology at all.
Price's work was essentially plagiarized by Henry Morris and John Whitcomb in the 1960 and became canonical for the YECers. This is obviously what folks mean when they claim that it is not just the biological sciences but ALL sciences that are attacked by creationists.
While we wait for Phil or other astronomers to give their expert opinion, I can try to answer the easy part.
Yes, conservation of angular momentum gives the match.
And since a protosolar nebula condenses a lot, the resulting sun would have a hefty spin. To explain that you don't see that, you have to have a mechanism that couples and distributes the momentum elsewhere. Magnetic braking would do that.
Hmm, maybe I can handwave some of the not so easy parts too: Another mechanism for angular momentum distribution is tidal forces. They will, rather slowly in comparison, brake planets rotation and even lock close by ones. Like Mercury, which is in a 3:2 orbit resonance with the sun. (There is an assumption of the planet rotation period faster that its orbital period here. Otherwise the planet must speed up to get locked.)
Conservation of total momentum should, in the slowdown case, if I'm not mistaken boost both the planets orbital angular momentum and (very slightly) the suns rotational angular momentum. So gravitational mechanisms redistribute the momentum in the system from where the magnetic braking placed it.
Tidal lock is interesting now then they start to find earth analogs around red dwarfs. The interesting planets, in the habitable zone, lie so close to the sun that they are tidal locked in a few million years. (Which is why I will try to learn some more about it.)
How fast a planet or star spins, depends on the mass and spin rate of what ever entity is buried there. Obviously for Jupiter to spin so fast, a pretty big and wound up entity is buried there. That would obviously be Jupiter. What causes an entity in its grave to spin, is doing something that pisses it off. Not worshiping Jupiter is obvously pissing Him off, so He spins, and so does the planet He is buried on.
Why is the Sun spinning so slowly? Obviously because the various Sun Gods that are buried there are not pissed off. The sacrifices of all those skin cells to a UV death by all those Sun worshippers is obviously propiciating the Sun Gods, so they don't spin.
Venus spins slowly because Venus is the Goddess of love and sex. The resurgence of sex as a fun thing to do is obviously not pissing off Venus, so She isn't spinning fast.
So where is God buried? The fastest spinning is occuring at the black hole that is at the center of our galaxy. Presumably what ever entity is buried there is way pissed off.
Torbjörn,
I'm afraid I have to disagree. Unless I've pooched the math, in a 1/R potential, the angular momentum of a unit mass in an orbit is going to be proportional to the square root of it's orbital radius. In other words, the nebula will have relatively little angular momentum (but high velocities!) where the sun is forming. (If you have a lot of mass in the nebula, you won't have a 1/R potential, but I don't think that'll change the general story).
That being said, the orbital period at the Sun's surface is only 2.8 hours, so the sun's slow rotation does call for explanation. I suspect the nebula also needed to dump a fair bit of angular momentum to be able to condense into the sun in the first place.
One further point. The sun is 98% of the mass of the current solar system. But it formed in a nebula that was likely many many times more massive than it. If I was looking for missing angular momentum, that's one of the places I would look. But I am not an astronomer.
It's not just stars: magnetic fields can also brake shopping carts.
Do'h! Yes, you are right, I was thinking purely rotational momentum when I wrote that (and even then the radius complicates things). But the main momentum is the orbital.
Blake Stacey, OM: For what it is worth, that craziness is not new. I seem to remember that Mario Bunge discusses it (as ridiculousness) in his 1959 book on causality.
While we wait for Phil or other astronomers to give their expert opinion, I can try to answer the easy part.
Yes, conservation of angular momentum gives the match.
And since a protosolar nebula condenses a lot, the resulting sun would have a hefty spin. To explain that you don't see that, you have to have a mechanism that couples and distributes the momentum elsewhere. Magnetic braking would do that.
Hmm, maybe I can handwave some of the not so easy parts too: Another mechanism for angular momentum distribution is tidal forces. They will, rather slowly in comparison, brake planets rotation and even lock close by ones. Like Mercury, which is in a 3:2 orbit resonance with the sun. (There is an assumption of the planet rotation period faster that its orbital period here. Otherwise the planet must speed up to get locked.)
Conservation of total momentum should, in the slowdown case, if I'm not mistaken boost both the planets orbital angular momentum and (very slightly) the suns rotational angular momentum. So gravitational mechanisms redistribute the momentum in the system from where the magnetic braking placed it.
Tidal lock is interesting now then they start to find earth analogs around red dwarfs. The interesting planets, in the habitable zone, lie so close to the sun that they are tidal locked in a few million years. (Which is why I will try to learn some more about it.)
Do'h! Yes, you are right, I was thinking purely rotational momentum when I wrote that (and even then the radius complicates things). But the main momentum is the orbital.