Friday, December 28, 2007

What it's like to observe at a major telescope

A new Youtube video describes what it's like to do observing at Mauna Kea.

Wednesday, December 26, 2007

Galactic Evolution

Blogging on Peer-Reviewed ResearchWe all know how much of a fit creationists throw over biological evolution. We've also seen just how much of a fit they throw fits over stellar evolution. But there's change on even bigger scales as well.

From Brahe’s observation of a supernova in 1572, to Arp’s catalogue of odd an interacting galaxies, to Hubble’s observation of an expanding universe, it has become quite apparent in the history of astronomy that we live in a dynamic universe; it evolves. However, the evolution of some systems is easier to trace than that of others. With stars, we can observe clusters, in which only the mass of the various components differs significantly, in order to test our theories of stellar evolution. Unfortunately, for systems as large as galaxies there is no analogue.

One of the main reasons for this is a difference in the way stars evolve as compared to galaxies. Most stars are, for all intents and purposes, isolated systems, separated by vast interstellar distances. Even for the rare stellar systems that are close enough to undergo some sort of transfer, these amounts are typically only fractions of the mass of the objects. Thus, the evolution of stars is governed primarily by internal forces. While galaxies have gas and dust by which they can change their properties by making new stars and building heavier elements, galaxies are never observed in complete isolation. They are always members of some cluster in which interaction is inevitable.

As such, galaxies are not only subject to internal forces, but are also acted upon by external forces when they interact with other galaxies through glancing blows, mergers, or even cannibalization. This is true even in our own galaxy. While our nearest major neighbor may be quite a ways away, the Magellanic Clouds as well as several recently discovered dwarf galaxies swarm around us.

The current theory of galactic formation is that early in the universe, star formation began in smaller systems, which accreted into larger systems as the universe aged (Wiklind, 2007). As such, we would expect massive galaxies to be more prevalent at low redshifts. However, recent studies such as one by Wiklind et al (2007) looking at galaxies in the HDF, have shown that many massive galaxies with aged stellar populations exist at redshifts > 5, indicating that star formation occurred within a few hundred million years of the Big Bang.

For the first time, with larger and more advanced telescopes, are we able to peer back through true cosmological time scales to begin to see how galaxies have evolved as the universe has aged. Powerful new surveys, such as the Cosmological Evolution Survey (COSMOS), are new letting us place constraints on fundamental questions about how galaxies evolve. Questions of the evolution of the number density, when periods of star formation occurred, morphology, and chemical evolution can now be explored.

Mass Accumulation
Since, as previously mentioned, one of the driving forces of galactic evolution is that of accumulation of additional matter, it is of interest to study how this process occurs. This accumulation primarily occurs in two ways. The first is through the accretion of matter from the intergalactic medium (IGM). The second is through mergers with other galaxies that have already formed. The importance of each of these depends on the properties of the local universe at the time. If a great deal of raw matter is still available in the IGM as compared to the number density of galaxies, then the former process will dominate.

Fig 1. Fraction of bright galaxies in close pairs (5-20 kpc) vs (1 + z) for COSMOS field. Vertical error bars are 1σ. Star indicates local fraction. (Kartaltepe, et al., 2007).

One way this question has been approached, is to analyze the number of galaxies in close galaxy pairs at various redshifts. This method was undertaken by Kartaltepe et al (2007). By analyzing 1,749 galaxy pairs from the COSMOS field and comparing the number of paired galaxies to the overall number, they determined that the number of galaxies in close pairs increased significantly throughout the history of the universe (see Fig 1). Their study extended to z ~ 1.2, but they suggested that if the trend were extended to a distance of z = 2, it would indicate that nearly 50% of galaxies were in pairs during that time. However, little has been done in terms of high quality investigations for such limits.

Another interesting study indicating that mergers can strongly influence the properties of galaxies examined the density of galaxies (Trujillo et al, 2007). They found that, at redshifts of ~2, galaxies existed that had a density almost two orders of magnitude higher than any found in the present universe. Because of this, they suggest that such compact galaxies must have merged with others.

But mergers are not the only form of mass intake which galaxies can undergo. Accretion of matter from the IGM also plays an important role. Simulations by Semelin and Combes (2005) have indicated that mass gained via accretion exceeds that of mergers by a factor of 2 to 4. Before z ~ 2, the importance leaned more towards the factor of 4 while more material was still available. After that time, accretion should have become less important. This is somewhat supported by a study done by Netzer and Trakhtenbrot (2007), which looked at the growth time of AGN at z < 0.75 due to accretion and found that the amount of time they should have formed in is older than the observed age of the universe, thus agreeing with the conclusion that the rate of accretion is decreasing towards present time.

Star Formation & Luminosity
The process of adding more material almost certainly induces periods of star formation in galaxies. Accretion passively provides new raw resources; mergers and close encounters provide perturbations necessary to trigger collapses, and can have dramatic consequences, as demonstrated by the M81 group. Where new star formation occurs, so is there an excess of luminous stars, brightening the overall galaxy. Thus, if there is a correlation between the amount of mass and methods of gain through cosmological time, there must also be a relation to luminosity.

Fig 2. Star formation rate at 1,900 Angstroms as a function of resdhift (Bouwens & Illingworth, 2006).

To investigate this, many authors begin by examining what should be expected photometrically from a passively evolving galaxy in which no new star formation is taking place. Observations are then compared to this standard. In this area, studies have indicated that more massive galaxies (typically taken to be M > 1011 MSun) show less evidence for luminosity evolution than their lower mass counterparts (Bower, Lucey, & Ellis, 1992). This suggests that the most massive galaxies underwent a large burst of star formation early in the history of the universe, but have not done any significant star formation since that time.

In other cases, significant evolution is frequently noted. A study by Dahlen et al (2007) investigated the star formation and luminosity functions for lower mass galaxies. They concluded that star formation rates have been increasing towards present time and that specifically, in the spectral regimes they examined, this led to an increase of nearly 1 magnitude since z ~ 1.73. Their survey did not extend past this redshift, but other studies have indicated that there may well have been a peak in the star formation rate near z ~ 2. This was the conclusion reached by Bowens & Illingworth (2006) and is illustrated in Figure 2.


Fig 3. Size - redshift relation for disk galaxies selected by absolute magnitude. Blue dots show the median value in each redshift bin used. The solid line shows the best-fitting size evolution (1+z)1+m, where m = 1.1. Also shown are theoretical curves if sizes evolve as r is proportional to H(z)-1 (dashed line) and r proportional to H(z)-2/3 (dotted line). (Dahlen et al, 2007).

Another consequence of the evolution of galaxies is that morphologies will change as galaxies evolve. While morphologies can dramatically change due to interactions mangling structure, morphology can also be driven by more quiescent processes, such as the location of star formation. Such an investigation was also carried out by Dahlen et al (2007). They discovered that the number of galaxies with structure dominated by their bulges drops, approaching present time, from an average of ~10% of galaxies at z ~ 0.5 to ~30% at a redshift of 2.2. They also find that the overall size of galaxies has been increasing towards the present, as illustrated in Figure 3.

Meanwhile, in the arena of morphological evolution, there seems to be a more questionable relation to mass and limits of evolution. According to Conselice et al (2007), galaxies with masses of 1011 MSun are observed to have a consistent fraction of ellipticals (~70-90%). Other studies, such as that of Cresci et al (2006), have also indicated that massive galaxy morphology may be more stable over long periods. However, for galaxies above 1011.5 MSun they discovered that there has been a ~20% increase in frequency of such galaxies since z = 1.2. Additionally, there has also been an increase in the frequency of the 1010 MSun spiral galaxies since the same time, where peculiar galaxies of that sort have decreased in commonality. These findings are shown in Figure 4.

Fig 4. Frequencies of various types of galaxies vs. redshift for two binnings of mass. (Conselice et al, 2007).

It should also be noted that there is a strong correlation between galaxy morphology and the number of other galaxies in near proximity. Galaxies in clusters are significantly more likely to be of the “early type” (elliptical and lenticular) than a typical field galaxy (Smith et al, 2005). As with most other properties, we may ask whether this correlation also evolves. The findings of Smith et al (2005) suggested that for most clusters, the likelihood of a particular galaxy being early type is roughly constant over the past 7 Gyr. Only the densest clusters they studied showed strong evidence of any evolution of frequency.

Chemical Evolution
As stars are formed and die, they inherently enrich their host galaxies. From my review of the literature, it appears that most of the investigation into this topic has come in the form of modeling and very little has been applied in the way of constraints. One of the few studies that does make this attempt is that of Fritze, et al (2002). They applied observations of Damped Lyman α Absorber (DLA) galaxies to various models for the chemical evolution of spiral galaxies. They concluded that these early DLA galaxies followed the general trend set forth by models, suggesting that they may well be progenitors of spiral galaxies we see in the universe today.

In this post we have investigated four major galactic properties as a function of redshift in order to infer the manner by which galaxies evolve with the universe. It was shown that the number of galaxies in close pairs has been decreasing as the universe has aged. Star formation has also been decreasing in recent cosmological times, after apparently having a peak near a redshift of z ~ 2. The issue of morphology tends to be somewhat more difficult to untangle, as many factors seem to have an effect on this property. In general, galaxies around 1011 MSun seem to be somewhat resistant to morphological evolution, although more massive galaxies seem to be susceptible. While chemical evolution also undoubtedly occurs, little seems to be available in the literature as to how this has related to redshift for various types of systems.

In general, evolution is an important a force in the universe at large as it is for life on Earth. It sculpts galaxies and makes them shine.

-Bouwens, R. J., Illingworth, G. D., 2006, Nature, 443, 189.
-Bower, R. G., Lucey, J. R., Ellis, R. S., 1992, MNRAS, 254, 601.
-Conselice, C. J., 2007, MNRAS, 381, 962.
-Cresci, G., et al, 2006, preprint, arXiv:astro-ph/06072212v2.
-Dahlen, et al., 2007, ApJ, 654, 172.
-Fritze, U., Alvensleben, V., Linder, U., Fricke, K. J., 2002, Cosmic chemical evolution. Proceedings of the 187th Symposium of the International Astronomical Union, held at Kyoto, Japan, 26-30 August 1997, 147.
-Kartaltepe, J. S., et al. 2007, ApJ, 172, 320.
-Netzer, H., Trakhtenbrot, B., 2007, ApJ, 654, 754.
-Smith, G. P., et al, 2005, ApJ, 620, 78.
-Trujillo, I., et al, 2007, MNRAS, 382, 109.
-Wiklind, T., et al, 2007, preprint, arXiv:0710.0406v1

Only another year away

Apparently 2009 is now the official International Year of Astronomy as dubbed by the UN to celebrate the 400th anniversary of Galileo pointing a telescope up instead of through window of the neighbor girl. Sounds like it should be pretty fun. Not that astronomy's not fun without getting a bit of extra recognition, but this is a bit of welcome news given that the UK astronomy program has been hit with budget cuts and our administration isn't well known for its support of science. Hopefully, this will dredge up a bit of public support.

Tuesday, December 25, 2007

Happy Whateverday!

It's been a rather busy last few days. I just got home in time to do a bit of shopping before the holidays. As I was out and about, it continually struck me, just how imagined the "War on Christmas" really is.

When driving, I tend to listen to classical music. The St Louis station (99.1 FM) declared itself "The spirit of St Louis Christmas". At Borders, the cashier wished me a "Merry Christmas" and I didn't punch him in the face or sue him (like good atheists are supposed to I suppose). At Best Buy, a large sign hung from the ceiling wishing shoppers a "Merry Christmas." Most of the churches I drove past on the way home had out their nativity displays.

So merry and a happy New Year!

Tuesday, December 18, 2007

Good Idea/Bad Idea

I'm always a fan of taking superstitious nonsense and replacing it with rational options, so in a sense, I'm quite happy to see this presentation by the Morehead Planetarium in North Carolina, in which they address the mythical Star of Bethlehem. However, if they're going to try and do such a thing, they should at least make sure to get the science right.

The article says it explores possible "astronomical explanations for the Star. Viewers can decide for themselves whether a blazing comet, an exploding or shooting star, a major eclipse, or a conjunction of planets might explain the reported event."

Seriously. A shooting star? Why is this even being brought up as a potential option. Shooting stars are meteors that zip across the sky in often less than a second. I hardly see any magi being able to chase that down.

The rest of their options have a similarly pointless approach. If it's anything outside our own atmosphere, then it's going to move. Funny that whole rising in the east, setting in the west thing. The only way something like that could not move (and thus allow the wise men to be able to follow it) was if it were near the North Celestial Pole (i.e. Polaris, the North Star).

This would rule out anything in our own solar system since the NCP is pretty far away from the plane of the solar system. Thus, about the only viable astronomical events left are novae (including the super variety). This sounds pretty good to me. A supernova in our galaxy could well be near the NCP.

But there's still another glitch. It would always look like it was still further North. Matthew 2:2 says:
"Where is the one who has been born king of the Jews? We saw his star in the east and have come to worship him."
So it looks like that's not going to work either. Additionally, such an event would have been visible in many more places and there are no other historical records confirming what would undoubtedly have caused a stir.

"Star in the east" does have somewhat of a familiar ring to it though. Since things rise in the east, the east is the direction by which morning comes. The planet Venus has two other names: Lucifer and Noctifer. The former means the morning star, whilst the latter means the evening star. Could it be possible that Venus was the "star" they observed since when it appears in the east, it only rises a relatively short distance before the sun rises? Sure. But only if you want to believe that ancients were completely ignorant of Venus before hand. Other sources have pointed to Jupiter, another planet that often appears as a bright star like object in the skies. But I would dismiss this for the same reason. Both Venus and Jupiter (although not understood) were familiar astronomical sights and both would have been visible either before or after (depending on whether or not it was in retrograde motion) ruling out the notion that it could have been a novel event.

Thus, the Star of Bethlehem does not have a good astronomical explanation. But this doesn't mean there isn't a good rational one: It never existed. Like so much of religious history, this event is likely either an exaggeration or fabrication, much like Sampson killing 1,000 Philistines with the jawbone of an ass in Judges 15. But somehow, I doubt this is the track the planetarium show will be taking.

Instead, I suspect they will make the same conclusion I did in the first part (no credible astronomical explanation) but then given credence to the inane philosophy of "if we don't know, that means your nonsense is credible!"

Monday, December 10, 2007

Book Review - Myth of a Christian Nation

Not too long ago, CNN had a special entitled God's Warriors. During the segment on Christianity, one of the people they interviewed was a megachurch pastor named Gregory Boyd. Astonishingly, he was arguing against the notion that America is somehow an inherently religious nation and that pretending it is, is not only harmful to our country and constitution, but also harms faith.

So back in October I picked up a copy of his book The Myth of a Christian Nation (Subtitle: How the quest for political power is destroying the church). I've been slowly plodding through it over the course of the past month and a half and finally finished it a little over a week ago.

The main theme of the book is that trying to control people by legislating morality is antithetical to the entire premise of Christianity. He points out that Jesus, although living in a politically charged climate, did not weigh in on political issues or try to influence the government. Instead of exerting a "power over" mentality, he tried to change people by transforming hearts to influence actions in a "power under" mentality.

American Christianity, Boyd points out, does the exact opposite; They try to influence action to control hearts. As such, instead of getting Christians that actually follow the teachings of Christ and befriend the downtrodden, we get arrogant, self-righteous, pious pricks. No disagreement from me there!

He illustrates the proper behavior of a true Christian on pg 144 where he describes the plight of a pregnant, unwed teen mother who was afraid to tell her parents of her pregnancy for fear they'd kick her out. Instead, she confided in a close family friend that, instead of passing self-righteous judgment, offered to support her in any choice she made, shelter her if her parents did kick her out, and help pay for the child should she decide to keep it. As a result, the girl did end up keeping the child. Boyd describes this as being truly "pro-life".

Boyd makes several other good points to support his argument. Another one was on page 137 in which he argues that perhaps the reason that American Christianity is so obsessed with homosexuality, is that that is (typically) the one sin they don't have (although some people suspect that it's also flogged because so many are and they're trying desperately to deny it). As such, they focus on that one in an effort to ignore their own faults. Hypocrisy at it's finest!

Another example at the marriage of Christianity to American politics Boyd gives is that it has become popular to think of the enemies of America as enemies of Christianity. Freedom is assumed to be a "Christian value" (Boyd points out it's not), and thus, when terrorists are out to "destroy our freedom", it's not only a war on America, it's a war on Christian virtues and thus, Ameri-Christians become even more incensed. This obsessive, bloody devotion to the perceived virtues of religion is what perpetuates violence, Boyd argues. Although he didn't mention it, this isn't a new trend either. While fighting Communism, religion was again used as an excuse to further conflict. They were "godless Commies" and since we're the God minded people, we are more righteous, and thus, we need to slap God on our money and pledge! American values are Christian values. Don't believe me? Check the billboard. Instead, we allow these wars to be perpetuated in the name of our perceived religion. Boyd seems to want to think that for a "true" version of Christianity, this would somehow be a different case, but as Voltaire pointed out, "Those who can make you believe absurdities can make you commit atrocities." After all, how many wars have been perpetuated in the name of Atheism? As Boyd puts it, it's hard "to motivate one group to kill another and be willing to be killed by others without convincing them that there's a religious dimension to their tribal cause." (p 100)

While I was reading much of this book, I happened to be listening to the cast recording of Les Miserables, and much of what Boyd was saying made a great parallel to the plot. For those that aren't familiar with Les Mis, it's partially the story of a sinner, Val Jean, who is released on parole, and then steals silver to sell from a pastor that took him in when no one else would. He is caught and instead of piously condemning Val Jean, he tells the officers that he gave Val Jean the silver in order to start a new life, "buying his soul for God." It struck me that this is precisely the point Boyd is going for. Had the pastor turned Val Jean away as so often happens, he would not have been saved and thus, no further good could come. The tit for tat, eye for an eye system would be preserved.

So this was the main theme of the book: American Christianity isn't real Christianity because they go for the bloody "kingdom of the world" mentality rather than the "kingdom of God." Americans are no more Christian, more pious, more pure, than the rest of the world. We just like to think we are. Boyd even goes so far as to admit that most American Christians "lack even an elementary understanding of the faith they profess." This is clearly stated in the first chapter, but then repeated in slightly different ways for nearly 200 pages. I have to sometimes marvel at how amazingly dense the average Christian must be if a pastor feels that he has to repeat himself for 200 pages to get a single point across.

Regardless, the main premise of the book was one that I could agree with. I'd love to see some Christians that were more humble and not condescending asses. If they wanted to actually be nice and try to "transform my heart" or whatever nonsense they'd like to call it, they're more than welcome to try, although I doubt it will get them anywhere.

But although I agreed with the main premise, this doesn't mean that there weren't things that Boyd said that I found either disturbing or flat out wrong.

One of the things Boyd constantly calls for is more prayer. Not the government sponsored type that so many Ameri-Christians are clamoring for, but personal prayer. He points out Americans "place more confidence in our individual and corporate political activity than [we do] in prayer (p 119)." On pg 177, he suggests that one person praying does more than an entire army. Instead of participating in the Civil War to end slavery, he suggets, we should have prayed our way out of such a large conflict. This is nothing short of complete stupidity given that studies have shown that prayer does not work. As the adage goes, "One pair of hands at work does more than a thousand clasped in prayer."

Boyd also argues for blind faith and ignorance. If you trust "worldly effectiveness" over "kingdom faithfulness", then it is a sign that you are relying too much on "common sense." Get that? He explicitly says that if you follow what works there is something wrong with you! Instead you should blindly follow your faith.

This is just part of the Christian mindset that should seriously disturb any right-minded person. Another aspect Boyd argues for is that Christians should make sure they're persecuted because "as terrible as they often are, persecutions have usually had a positive kingdom effect (p 181)." I think I'll have to go with Charles Bradlaugh when he said, "I cannot follow you Christians; for you try to crawl through yourlife upon your knees, while I stride through mine on my feet."

Overall, the book made a point that I think should be taken to heart by Christians. If Christians actually practiced what Boyd preaches, I wouldn't have nearly as much of a problem with them. However, it's just replacing one form of nuttery with a less offensive, but no less crazy form. In fact, it seems to me that Boyd's form is more ludicrous when it advocates giving up rational thought for faith, but at the very least, it's certainly less dangerous to our Constitution and to the world in general.

Friday, December 07, 2007

Sleep is awesome

After having nearly a dozen assignments due this week, between term papers, lab reports, general homeworks, projects and presentations, I'm finally finished. Oh it feels nice.

Friday, November 16, 2007

Pareidolia: part n + 8

Over at Stupid Evil Bastard, Les lets us know about a new pancake with a mysterious image in it. Apparently, the woman who made the pancake thinks it's Jesus and Mary. But we all know that's wrong. It's quite obviously the Flying Spaghetti Monster. She was touched by his noodly appendage and was too blind to see it. No beer volcano for her!

Exorcism kills again

It seems that another woman has died due to a failed exorcism in New Zeland in which she had syringes suck into her eyes and was forced to drink excessive amounts of water. Did New Zeland not take the lesson from people here in the US when a woman died of water poisoning in a contest?

To make things worse, the same treatment was also forced upon a 14 year old. Furthermore, the police weren't called until l8 hours after the woman died. If someone stops breathing, I would think you would call for help immediately, unless your ability to think has been impaired. What were they expecting? A magical resurrection like Jesus?

Thursday, November 15, 2007

Finding New Stuff with Big Sky Surveys

Blogging on Peer-Reviewed ResearchOne of the coolest things about astronomy is that we live in a universe. A big universe. And that means that there's a lot of fun stuff to find out there. It's like a never ending easter egg hunt. Unfortunately, these eggs don't contain chocolate. But they do glow in the dark, so that's pretty cool.

What's especially amazing sometimes, is that we are still trying to catalog our own galactic back yard. Phil Plait at Bad Astronomy addressed the reason for this (transcript), namely that things are pretty darn faint. So, even in our own galaxy, we can't really see terribly far.

Break out the telescopes, and many more things become visible. But then you start to run into some other problems. First off, we live in a spiral galaxy. Spiral galaxies are partially known for having large amounts of dust and gas. So it's a lot like trying to look around in a fog bank. You can't see too far. Another problem is that the further away things are, the smaller they are in angular size. So even if something is relatively bright, you might not even notice it in all the clutter.

Historically, new objects were discovered just wandering around the sky with telescopes and documenting anything that was suspicious. This was the foundation for the famous Messier Catalog. Now, serendipitous discoveries along those lines don't happen too often, although, they occasionally still do.

Today, instead of wandering aimlessly across the sky, new discoveries are often the result of computer controlled survey missions. Sometimes the astronomers know what they're looking for. Other times, new discoveries are simply a byproduct of other data taking. An example of the latter is the numerous comets discovered by the SOHO mission which has discovered over 1,300 comets (including it's first perioditic comet recently).

Another example is the Sloan Digital Sky Survey (SDSS), which slowly scans the sky, taking high resolution images with its 120 megapixel camera. Sloshing through this data, a group from the Max Plank Institute with Cambridge astronomers have discovered 2 new globular clusters in our galaxy (Kopsov, 2007). To do this, a computer program mapped the stars imaged in the survey and looked for places where there were spikes in the density of them. But a jump in the density of stars alone doesn't tell astronomers what the object is.

Since not only our universe is big, but we also live in a pretty good sized galaxy, our galaxy gets to be a bit of a bully. This means we cannibalize dwarf galaxies. So when we look around some of the overdensities can also be the result of these tiny doomed galaxies.

So how can we tell the difference? One of the main ways is to look at their HR diagrams. If it's a cluster, all stars will have formed at the same time, and thus, you should see something resembling an isochrone. If it's a galaxy, then stars would have formed at largely different times and there should be no distinct turn off. Since the color-magnitude diagrams (CMDs, essentially an HR diagram) show distint main sequence turn offs, the possibility that these are distinct galaxies can be ruled out.

Now that we know that these are clusters, what can we say about them. One of the first things that the paper notes is that these clusters are faint. Each is estimated to have a total surface brightness of -2 to -1 magnitudes (remember, in the magnitude system, bigger numbers are fainter. Thus, a -20m object is brighter than a -15m object. Similarly, a 1m object is brighter than a 2m object.) To date, the faintest globular clusters ever found had magnitudes of roughly -1.6.

Additionally, these two new clusters are way out there in the halo of the galaxy. Finding faint galaxies that far out hints that there may be a lot more of these bitty guys out there that have yet to be discovered. So why are they so puny while most of the inner globulars are nice and big?

It looks like these clusters are falling apart due to the tidal stripping that keeps coming up in my posts. This would suggest that in the past, there were even more of these and they were bigger. But fear not creationists. The current estimated lifetime for clusters with this density is about 8 billion years. So the evaporating comet nonsense doesn't work for these objects either.

But globular clusters aren't the only objects lurking in our galaxy that are yet to be discovered. In another paper from the same ApJ issue discusses some more findings from another sky survey. This one was looking for planetary nebulae (Cohen, 2007). These guys don't last all that long before they spread out and blend back into the interstellar medium. But since they're the result of low mass stars ending their lives and there's a good number of stars doing that, there should be a pretty good number out there.

However, since these form from dying stars, we should expect more where there are stars, namely, in the disk of the galaxy. So unlike globular cluster hunting, we have to look close to the galactic plane. Unfortunately, this means there's going to be a lot of extra dust and gas in the way hiding them.

The Macquarie-AAO-Strasbourg Hα PN project (MASH) again uses sky surveys to look for these objects. Instead of looking for density spikes, they look for objects with emission due to hydrogen and then compare the brightness of that in the mid-infrared part of the spectrum, to the brightness in the radio as well as differences in spectra to distinguish the objects from other objects that may masquerade as planetary nebulae (such as HII regions).

So far, this study has found 905 new objects that are likely to be planetary nebulae in our own galaxy! This has increased the known number by ~60%. Wow! This paper alone added an additional 58 to that list. Many of these new nebulae are quite evolved and starting to diffuse back into the interstellar medium, so having this large collection of additional objects will allow us to put new constraints on these objects and figure out how they evolve.

Another thing this survey gives us is a lot of new PNe morphologies to study. Ideally, they should all be nice and symmetrical (since stars are round and all). But the universe is never idea (*sigh*). Stellar rotation, magnetic fields, asymmetrical releases, companion stars and all sorts of nasty things whip planetary nebulae into odd shapes. There's so many ways to do things that it's hard to untangle them all and hopefully, having more to study will untangle the mess. Roughly 28% of these new PNe are bipolar which is a pretty significant number.

So now we've seen two examples of how large sky surveys are uncovering scores of new objects that can help us learn about the universe we live in. Nice little benefit of these things that is, but there's also a downside. Having gigantic surveys like this generates loads of data. Way more than astronomers can possibly sort through. That's why we've been seeing projects that are starting to put some of the grunt work in the hands of passionate amateurs. Hopefully we'll develop more sophisticated ways of handling the terrabytes of data that can be generated in a single night of observation.

Koposov, S., de Jong, J.T., Belokurov, V., Rix, H., Zucker, D.B., Evans, N.W., Gilmore, G., Irwin, M.J., Bell, E.F. (2007). The Discovery of Two Extremely Low Luminosity Milky Way Globular Clusters. The Astrophysical Journal, 669(1), 337-342. DOI: 10.1086/521422

Cohen, M., Parker, Q.A., Green, A.J., Murphy, T., Miszalski, B., Frew, D.J., Meade, M.R., Babler, B., Indebetouw, R., Whitney, B.A., Watson, C., Churchwell, E.B., Watson, D.F. (2007). . The Astrophysical Journal, 669(1), 343-362. DOI: 10.1086/521427

Wednesday, November 14, 2007

DI in the Whaaaaambulance

A long time ago,
In a blog post far far away...

I wrote a list of talking points for making a pro-ID/Creationist arguments.

The first point under the section about defining Intelligent Design read:
Remember to as vague as possible. Do not mention what ID actually says about common descent or age of the earth so that fundamentalists won't get offended and will continue giving you funding. Additionally, not adequately explaining yourself will give you the ability to dismiss critics later by insisting that they just don't understand Intelligent Design.
The list was based largely on a flopped presentation Dembski had given at KU but also drew from several years of watching other ID proponents presentations and observing their responses to criticism.

But it seems that the Discovery Institute is showing just how true it is in response to PBS's Judgement Day: Intelligent Design on Trial. Crowther claims that the show misrepresented ID. Yet this documentary wasn't their words. It was straight from the mouths of the ID proponents themselves!

- We had Buckingham and Bosnell being open and honest that they were Young Earth Creationists and they wanted it in the classroom in any way they thought it could fit in (and then perjuring themselves as to where the books had come from).
- We had Behe and Minnich define ID for us and be so utterly vague about it that Behe had to admit that astrology would be science.
- We had the DI's touted textbook, Of Pandas and People being caught in the act of giving the facelift to Creationism (and even leaving us transitional fossils to demonstrate it.
- We had the DI's own Wedge Document in which they clearly state their objective as "nothing less than the overthrow of materialism and its cultural legacies".
- We had repeated quotes from Phillip Johnson, the founder of your own movement, admitting that, "Our strategy has been to change the subject a bit, so that we can get the issue of intelligent design, which really means the reality of God, before the academic world and into the schools."

These aren't our words here Disco boys. They're the words of people on your side.

In my last post, I wrote about how Behe and other ID proponents have failed to learn an important childhood lesson, namely, that if you act like a fool, you're going to get made fun of and you have no one to blame but yourself. Now, we catch them in their immaturity in yet another way: Adults know how to take responsibility for their own actions. Even Richard Thompson from the Thomas Moore Law Center admitted it was a "fair trial". But it seems that the Discovery Institute won't admit that they need to take responsibility for their actions and that they were beat in a fair fight. Instead, all we get is spin, spin, spin, rationalization, spin, spin.

Perhaps one day, creationists can all grow up.

Karma's a Bitch

One of my earliest posts in this blog, was a commentary on one of the fundamental points most of us learned in elementary school: If you want respect, earn it. The gist of that blog was that if you repeatedly reject the option to earn some respect and instead act like a fool, then you deserve to be ridiculed.

Unfortunately, this lesson is one that Behe, like so many other creationists, seems to have never learned. Instead, they continue to make a mockery of the very foundation of science, making grand claims that go unsupported, offering up untestable hypothesies, fallacies of bifurcation, maintaining willful ignorance and downright lying. Of course, Behe keeps up this fine tradition.

So when ERV decided to take on his nonsense and give Behe the well earned ribbing he's earned. But maybe Behe's finally learned the lesson that is even obvious to most children. So he posts an announcement saying he's going to rebut the letters directed towards him. It's a grand flourish and I was sincerely hoping that Behe was setting up for something big and would actually, I don't know, address the arguments?

So what's the first thing he says?

"Whhhhhhaaaaaaah. I'm being made fun of."

That's right. Behe plays the victim card and claims that he's the victim of an ad hominem attack. But he wasn't. For a real ad hominem, it requires that the offender substitute an argument with a mocking. This is not the case. Rather, the argument was supplemented with a mocking that matched the mockery Behe and his fellows make of science.

But after that, is Behe finally ready to grow up? I'm not going to pretend I understand the technical exchange any more than Behe would be able to follow articles in the Astrophysical Journal (although Behe's buddy Dembski apparently knows everything about everything), but there's a few keys phrases that are amazingly typical of creationists trying to worm their way out of being confronted with evidence.

#1) "It is not clear to me why you call that Smith’s "core argument."" - Translation: I don't get it because I'm too busy repeating my claims ad nauseum to actually read anything. Careful Behe. You let that pesky reality pile up on you too long and it will bite you in the ass like it did on the stand at Dover.

#2) " her own citations show" - Translation: her own citations show if you ignore everything except that introductory sentence used as a literary device, disregard all the evidence that supports her and buy into my quote mining bullshit. FTK might consider out of context quotes as indicative of "an open issue", but those of us that keep reading to discover the issue is well on the way towards a resolution don't buy into such sleazy tricks.

#3) "I think this is a trivial biochemical change..." - Call it trivial and ignore it. Or if "trivial" isn't your cup of tea, you can always call it pathetic.

I'll wait for a layman's version of the technical bits, but right now, it's looking pretty clear that Behe is just up to the same old nonsense: Flaunt, cry, obfuscate. Someone let me know when the reruns are over and something new is on.

Meanwhile, Behe has the audacity to say, "One of the very basic prerequisites for education is to be able to engage in civil discourse...".

Guess what Behe, so is actually backing up your arguments without lying.

The M81 Group

Blogging on Peer-Reviewed ResearchAs I've mentioned before, M82 is one of my favorite galaxies. It's an exciting galaxy that had a collision with its neighbor M81, which is also chewing on NGC 3077, a while back. The results of this are having all sorts of exciting effects not only on M82, but also in the resulting mess from the collision.

These galaxies look like they're quite independent, but when astronomers Yun, Ho, and Lo started mapping atomic hydrogen in 1994, it turned out there were large bridges of gas between the galaxies. This sort of thing happens when galaxies interact due to tidal forces; the galaxies get stretched because the end closer to the other galaxy is being pulled on more than the far end. This is very well illustrated by galaxies that are very obviously interacting, such as the Mice or the Antennae. We can even find these long stretched out tails around our own galaxy where we've torn apart dwarf galaxies that have gotten too close.

But not to be content with just saying that the galaxies were related, astronomers went so far as to actually model the system and try to recreate the observed structure! This isn't an easy task with even two galaxies, but here we have three that are interacting. In this image, you can see just how closely their result matches with the actual observed morphology. The overall shapes, the angles, the relative sizes all match with amazing precision. Pretty nifty.

Meanwhile, tidal tails aren't just pretty. Clumps can form in them, containing thousands of times the mass of the sun worth of raw materials. In some of these knots, large numbers of young, blue stars have been discovered, suggesting that they can form new dwarf galaxies (Markova, 2002, Ciardullo, 2004). But this high rate of new star formation isn't limited to the tidal tails. M82 is undergoing such high star formation that it's blowing the galaxy apart.

I've talked a bit about how galactic interactions form new clusters, but M82 has them aplenty! Of the 650 clusters found in M82 by Chavez et al., 400 of them are in the area where starburst is no longer occurring, but that still leaves 250 brand new clusters in the area where the highest amount of star formation is taking place. And these clusters are massive.

Although these newly formed clusters have a distinct difference from what are typically considered to be globular clusters, it's possible that they may be the precursor to globular clusters. To determine this, the group is looking at how well such clusters can survive aging. To make it, clusters need to be able to survive three main processes.

The first is the pressure from early supernovae when the massive stars die. This is nicknamed the "infant mortality" stage and it lasts about 107 years. Next up is mass loss from stars decreasing the overall mass of the cluster and allowing it to drift apart. Another factor of 10 longer and if the cluster's still there, it should be OK. Last up are multibody interactions. There's two main forms to this. One is something I've discussed previously: tidal stripping. Just like the interaction of the galaxies in this association can draw out tidal tails, the same happens to clusters as they orbit the galaxy. As they get drawn out, the cluster disperses. The other is gravitational interactions within the cluster itself. Some stars will pass too close to another star and get a gravitational slingshot out of the cluster, again adding to loss. But if the cluster can make it past all these hurdles, and become a "relaxed system," it should be relatively stable.

The ones that survive become full fledged adult clusters, either globular or open depending on the number of stars. The question is whether or not these supermassive star clusters in M82 will survive to adulthood. Fortunately for the clusters in M82, they've already hit the 107 year mark, so many are well on their way. Based on their masses and sizes, the group expects that many of these clusters should survive to become brand new globular clusters.

And of course, where there's new stars, there's massive stars. And massive stars live fast, die young, and go out with a bang. More accurately, they go supernova. And as I've mentioned before, supernovae help seed the universe with heavy elements. Interestingly enough, the ratio of Silicon and Sulfur to that of Oxygen is unusually high. Too high, it seems, for the typical run of the mill supernovae to account for it. Thus, Umeda et al. (2002), have suggested that a good number of these massive stars were so massive, that they didn't end in just regular supernovae, but rather as the even more powerful hypernovae, which have a different metal output. Given that the lifetimes of these massive stars are nearly identical (~107 years) to the time that the rapid star formation occurred, this would seem like a plausible scenario since it would otherwise be a surprising coincidence.

It should go without saying that these huge supernovae are putting out some pretty intense stellar winds, which are whipping up the remaining gas, making huge bubbles. One group thinks that the shock front may be the cause of compact radio sources. The other leading hypothesis is that supernova remnants themselves may be the source.

Radio isn't the only non-visual regime in which there's some activity though. M82 is also highly active in the X-ray due to some supermassive black holes that are enjoying a feeding frenzy with all the activity. But black holes aren't something I've been much into, so I won't bother going into any detail on the current work.

Regardless, M82 and the rest of the M81 group is a pretty exciting set of galaxies in which a lot of fundamental astronomy is happening.

Yun, S., Ho, P.T.P., Lo, K.Y., Nature, 2002, 372, 530.
Makarova, L. N., et al., 2002, A&A, 396, 473.
Mayya. Y.D., et al. 2007, arXiv:0710.2145v1.
Hideyuki, U., et al., 2002, ApJ, 578, 855.

Saturday, November 10, 2007

Why I'm Happy To Be An Atheist

Being an atheist isn't all gloom and doom. I'm not angry all the time. There's actually a lot to be happy about.

One of the problems I have with the theist mindset (which is especially prevalent among the creationists) is that it looks for the easy answers out. "Why bother with thousands of journal articles when can have all my answers packaged in one book?" it asks.

With atheism, you don't get any prepackaged answers. Science has become the default explanation, but unlike theists, those answers had to be worked for, instead of just having them handed down from on high. This alone doesn't mean they're any better any more than building your home yourself is any better than buying one.

But from these conclusions, we can instill messages. Fellow SOMA member Chuck Lunney put it,
Rather than being created apart and unique from the rest of the living biosphere, accepting the fact that humans are part of and intimately connected to the universe makes me care intensely about every little thing that exists.
But it's not necessarily the answers and the messages we instill from them that are what it's all about. It's also the process of getting there. The idea of not taking the easy answers and taking things for granted that comes from the atheist mindset is something that has greatly influenced me as a person.

As my mother will tell you, it's made me fiercely independent. I'm not one to ask for favors or hand me downs lightly. Struggling to overcome my own problems has made me explore the limits of who I am and what I am capable of.

This mindset has given me a consistent, logical approach to problem solving that extends just beyond examination of physical realities. The same methodology can also be used in the interpersonal relationships I share with friends. Spending the time to investigate emotions and the connections I share with others has lead to some very deep and amazing friendships that I cannot even fathom experiencing with a mindset that promotes blind acceptance and shallow thought.

Another advantage to this mindset is that it avoids hasty and irrational decisions. Every time I've heard about people being taken in by the silly Nigerian Email scam, it's always someone taking a "something for nothing" offer on blind faith. In several instances, victims have thought God was telling them to help this person (and help themselves). This is not to say that atheists are immune to such scams, but having a mindset that requires actually holding answers up to some sort of scrutiny greatly decreases the chances of getting taken in by frauds.

Another one of the things I'm quite happy about is that I have a general optimistic view of humanity. Unlike religion, which tells us that humans are all awful sinners and deserve eternal damnation unless they accept the particular deity of choice, atheism carries no such inherent emotional baggage. We're free to actually make informed decisions on one another. As I already noted, this doesn't mean we trust anyone willy nilly, but it does allow for optimistic skepticism.

Lastly, I'm glad for my time. Not just that I get to sleep in on Sunday mornings, but that I get to actually live my life without absurd notions about what I have to do or not do to to ensure eternal life. It's freeing to know that my time is my own and that, when I do give it, it's because I do so knowing I care about friends and humanity, and not because I'm trying to earn karma points for the afterlife. I have my life, and I'm not about to waste it in prayer, or kissing God's Hank's ass, or mumbling worthless incantations.

I'm going to live it fully; Without reservations, self loathing, blindness, or any of the other nonsense that comes with the theistic mindset. This is what the atheist mindset gives us: Life.

And that's precious.

Friday, November 09, 2007

Wednesday, October 31, 2007

Phelps is now spelled Pwned

Earlier this year, the Phelps family was slapped with a lawsuit for invading the privacy of a funeral, and today the jury reached its verdict. Phelps owes $10.9 million in damages.

Apparently, when the verdict was read, "members of the church greeted the news with tightlipped smiles."

Of course they're happy. It just gets to further their persecution complex and they get yet another moment in the spotlight to be the attention whores they are.

I so angwy!

The other day, I stumbled across this blog post by Greta Christina which addressed her response to the generic question of why atheists seem to be so angry at religion. It's a good post and I encourage you to read it.

But I figured I'd post my own answer to that question (although far more generically than Greta). After all, I do call my blog the "Angry" Astronomer. So why am I angry?

Overall, I'm not. I'm actually pretty laid back. For the most part, I'm more angry and frustrated at my homework than religion. The difference is, my homework doesn't really affect anyone besides me (and possibly the graders and professors). And even so, homework isn't going to be around the rest of my life.

In contrast, the effects of religious thinking have enormous bounds that effect everyone and everything we come in contact to, has done so for thousands of years, and will undoubtedly continue to do so in the future.

So even though at present time I'm more concerned about that whole graduating thing, it's ultimately not as important as the effects religion has.

What most people asking the "why are atheists so angry" question don't quite realize, is that most atheists have very little against religion and mystical thought here and there in general. This is an obvious generalization as I also know a select few atheists who do have a vendetta against religion due to the serious emotional (and in a few cases physical) harm it has caused them, but overall, we just don't care what you think.

If you want to imagine a magical sky daddy created the universe 4.3 billion years ago, or 6,000 years ago, or even last Thursday, fine. No problem there! We'll laugh at your insistence on knowledge in the complete lack of any sort of supporting evidence, but whatever. You're entitled to your beliefs.

And even if you're a complete nutball that truly believes in Last Thursdayism, that doesn't mean that you're a complete nutball in every other aspect. As is frequently noted by religious people, many of the greatest minds in history were religious. And I have no problem with that.

But what this goes to show is that non-empirical thinking can be compartmentalized. In other words, you can believe in fairies, but that doesn't mean that everything is about fairies. As long as you can keep the non-rational stuff where it belongs, there's no problem.

The trouble comes when that compartment leaks, or worse, is intentionally opened like a Pandora's box. Suddenly, we have people going around insisting that "belief" in something makes it instantly credible and worthy of time, money, resources, and human lives.

Let's pretend for a second that religion doesn't unjustly consume an inordinate amount of all these and instead, look at some other things. Even if religion wasn't, the benign acceptance of the principle that religion endorses ("belief" = credible), spills over to other areas.

Historically, this has been disastrous. The belief that consuming mercury was good for your health certainly didn't help anyone. Especially Qin Shi Huangdi who took mercury pills and ended up going insane.

But magical thinking didn't stop hurting humanity thousands of years ago in China.

Today, that tradition is carried on with pseudoscientific garbage like What the #$*! Do We Know and The Secret. After endorsing that nonsense on her show, Oprah then had to go back and tell one woman not to throw her life away by trying to imagine her cancer away.

The belief that parts of the tiger's body can be used as an aphrodisiac (as well as for other mystic treatments) has, until recently, largely contributed to the near extinction of this species.

Magical thinking continues to kill today in Africa when people buy into the myth that their HIV can be cured by raping virgins. Not only does this lead to the transmission of deadly diseases which infects over 30% of the population of some African countries, but the emotional scarring that goes with these despicable acts.

It should go without saying that non-empirical based thinking isn't just silly; It's dangerous.

And not only is religion nothing but non-empirical, magical based thinking that has historically done great harm, it goes one step further. Religion codifies nonsense. It encourages people not to think, not to question. It says it's ok to cling to and do things based on irrational belief.

As such, it makes me exceptionally angry that an institution that promotes dangerous thinking is not just tolerated, but welcomed. Humanity is better than this. Yet the majority of Americans is perfectly content to buy into a perilous fantasy world. And as history as shown, they can do serious damage to the rest of us.

So again, while silly, unfounded beliefs here and there aren't particularly harmful, when that compartmentalization begins to break down and affect people in general in exceptionally harmful ways, then there's a problem. And it makes me even angrier that those people perpetuating the problem refuse to admit there's anything wrong!

But until the religious community starts taking a good look in the mirror and realize the damage they're helping along, I, and I'm sure other atheists, free-thinkers, humanists, rational-theists, and others, will continue to denounce the injustices.

And perhaps have some hot tea too...

Wednesday, October 24, 2007

Comet 17/p Holmes

As noted by the Bad Astronomer a comet that was until last night 17th magnitude (too faint to see with even many modest amateur scopes without ideal conditions), suddenly got over 400,000 times brighter in a single night and brightened to ~3rd magnitude!!! This is visible to the naked eye even under typical light pollution!

I grabbed my telescope and headed outside tonight to find it. The first thing I found was that my finder scope was misaligned, but once I fixed that, the comet was quite easy to find. Sadly, I didn't have a good camera with me and even if I did, it's quite difficult to get it set up to do the longer exposures to get good shots of comets, but I tried snapping shots through the eyepiece with a point-and-click digital.

One shot came out fairly close to what I actually saw through the eyepiece, so here it is:

Typically, when comets get significantly brighter it's because a large pocket of gas was liberated and spewed off into space. But the halo of this comet seemed amazingly symmetric. I was hoping to see a bit more lopsidedness if there was such an outgassing. Very odd, but very cool all at the same time.

Tuesday, October 23, 2007

My thoughts on Flock of Dodos

ERV has become one of my new favorite bloggers recently. Today, she put up an interesting post on what she thought of Randy Olson's Flock of Dodos. I saw it back in February but never really said anything about it. For the most part, I agreed with Olson's premise: ID is garbage, but it sells better because its proponents are more charismatic and better speakers and scientists need to pick up their end if they want to have a chance.

But ERV disagrees, saying:
I do not want to have a beer with Bill Dembski. I dont want to have a beer with Michael 'LiLo' Behe. They are not 'nice people'. They are not 'charismatic speakers.' Theyre professional con-artists and pathological jerks. Whats so nice about attacking students? Whats so nice about Behes non-science reply? Theyre jerks.
While I agree with ERV completely on this, I think she misses the point:

We're not part of the typical every day community. She and I are both in the scientific field. When people make scientific claims, we analyze it using the scientific standpoint. The average American doesn't really know jack about how science works.

As such, the general populous judges by other, less critical standards. Quality of presentation is one of them. But Dembski sucks. Behe wasn't bad but some of the "points" he made were so full of gaping holes that anyone should be able to catch them. So I'm with ERV on suspecting that good speaking isn't what ID really has going for it.

Rather, it's nothing but a case of confirmation bias. People want to believe there's a higher power and don't like that pesky evolution (presumably) telling them that they're born from monkeys. Thus, they'll buy whatever nonsense tells them what they want to hear. Throw in the persecution complex and it's ripe for lapping up.

Sadly, while ERV and I wouldn't eat with people as intellectually dishonest as Dembski, Behe, Luskin, or any of those other clowns, we're not John and Jane Six-pack (I don't even like beer). So the point I think Olson is really addressing is that this isn't going to change. We can't educate a nation full of people who are quite happy with their ignorance. Rather, we have to play the ID game too and make our public image better.

The question is whether or not the scientific community wants to play the "lowest common denominator" game, or more importantly, if it can afford not to. After all, the image of stuffy, elitist scientists doesn't do much for our cause.

Which brings me to the second point of ERV's; Flock of Dodos only reinforced that stereotype and in a very dishonest way:
Get a bunch of drunk scientists together and have them talk about Creationists. Thats a great idea *rolleyes* Get a bunch of drunk scientists together and get them to talk about some topic in HIV research-- youll get the same response. Belligerent, yelling over one another, good times.
This is dead on the money for me. Putting a bunch of intoxicated scientists up against slick snake-oil salesmen who have time to practice their talks and plan out what they're going to say? Yeah... there's an honest comparison.

This isn't to say that scientists don't have some sort of ivory tower mentality. Many do (although whether this is a cause or effect isn't well determined imo). However, as ERV pointed out, many scientists are perfectly friendly, and very good at getting their points across: Ken Miller, Phil Plait, etc...

At the end of the semester, all of my students fill out teacher evaluations. They're given space to write in opinions, whether good or bad. Thus far, I've never received a negative comment. Rather, comments have been overwhelmingly positive and quite often amusing (such as "Jon is the shiznit!").

Meanwhile, I've had a number of professors that, even as an interested student, were some of the most horrible people I've had to deal with. Missouri State University's physics department was much worse about this than KU's*, but there's always a few (comparatively) bad apples.

Long story short, scientists aren't the best at mass communication, especially for hostile audiences. So randy is right on that point; There are bad apples. But this doesn't mean that it's fair of Olson to put some of our bad apples against their best oranges.

*Not all of MSU's physics faculty is horrible. Dr. Broerman is a notable exception. How can you not love a chain smoking professor who looks like a cross between Dr. Zoidberg and Einstein?

Wednesday, October 10, 2007

"Good Answers"

I've mentioned before that one of the nifty (or creepy depending on how you look at it) features of Gmail is that it scans through your Email and recommends links that should be of interest to you. Today, it gave me one to an Every Student (a fundamentalist Christian group that targets students) web page on the existence of Adam and Eve.

It looks to be a sort of FAQ where people ask questions and then the Every Student staff answers it. This particular question asked:
What proof is there for the story of Adam and Eve as the first human beings on earth?
The Every Student site responds saying it's a good question that "requires good answers" and that there "is good evidence to believe the story of Adam and Eve".

What is that good evidence you may ask?

Five paragraphs of "the Bible says so."

I'd laugh, but I can't help feeling it's amazingly depressing that anyone can be so completely devoid of logic that they would buy such an answer as legitimate or logical.

Friday, October 05, 2007

REPOST: Dembski at KU (January 2006)

Over at her blog, ERV has had a string of posts discussing Dembski's recent talk in which he made himself look like an absolute fool, dancing his way around questions without addressing them, admitting his promotion of ID had religious motives, tossing out blatant contradictions, saying that no amount of evidence for evolution could convince him, and more...

I'd encourage everyone to head over and check out her series of posts (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).

But if that isn't enough Dembski antics for you, I've reposted my summary of Dembski's talk here at KU from January of last year. It's cute to see he still hasn't changed his tune. One of the most amusing instances in the KU talk was when a student asked him for positive evidence for design (as opposed to whining about how ineffective evolution is to someone who has already decided it's false). Instead of actually addressing the point, he said it would "require an entirely different talk" despite the title of his KU talk being "Evidence For Design"!

Meanwhile, while you're at it, you may want to see how closely Dembski has followed my Steps to Making a Pro-ID Argument template.

This post is originally from late January 2006 and was published in my livejournal.

My venture to see Dembski speak started as I arrived at the center nearly an hour before the presentation was due to start. When it hit 7:00, the lights dimmed and a short video started featuring clips of interviews from students at our campus giving their thoughts on various questions on Intelligent Design. Most seemed to tout the “teach the controversy” idea. The only exception was one girl that dismissed it as pseudoscience and said it should not be taught.

From there, the president of Campus Crusade for Christ (CCC) came out to introduce the speaker, urging audience members to keep an open mind as it was apparent there is much confusion on the matter of Intelligent Design.

Then Dembski emerged. He began his speech by saying “Darwin was undoubtedly a great man, with a great idea,… but evolution is not the whole story.” He then proceeded to outline how evolution was excellent on explaining small-scale changes, but has failed to explain the emergence of species, account for the Cambrian explosion, or predict cellular machines. He labeled evolution as being a “global disciplinary failure”. Next, he discussed Intelligent Design, pointing out that it is misunderstood and that it has been labeled “Creationism in a cheap tuxedo” although the person responsible for that quote has since updated it to an “expensive tuxedo”. Dembski attempted to counter that Intelligent Design sees little to no funding. Around the end of November the NY Times published an article that demonstrated that ID supporters were asked to submit research proposals for grant money, but none were ever turned in. Thus, the claim that ID sees no funding is untrue. Perhaps if they’d take their money and invest in research instead of advertising they’d have a better time of it.

From there, he quickly attempted to explain the evolutionary process. His analogy was of being at a mall with a million other people and playing a game in which everyone flips a coin (why a mall I’m unsure). He also tried to go into detail of a penny, explaining what one was (a “homogeneous disk…with a heads and tails”). However, he stumbled over terminology and made himself look as if he hadn’t bothered to prepare his lecture. In this game, everyone flipping tails sits down. Statistically, after the first round 500,000 would sit down. Generally after 20 rounds, only one person would remain standing. This would be a random process generating favourable results.

For those that have read this thread, or understand how evolution works would realize that this is an oversimplification in order to set up a strawman. Evolution in no way is a random process as Dembski asserts.

Next, Dembski went on to define Intelligent Design. His definition was basically that ID is the “study of processes in nature that imply design”. Dembski then attempted to outline the “design process” that we take saying it has “four or five steps”. His explanation was confused and he tended to backpedal frequently. In the end, he wasn’t able to count the number of steps in his own explanation, which instilled great confidence in his mathematical skills to me.

In effect, his explanation was that first a plan must be conceived, then materials procured, transported to the appropriate places, and assembled (I count that as 4 steps). He then explained that we see this process in cells and compared the structure of a cell to an “automated city”. By this, he inferred that, unless things could be built up by the process of evolution, which can only take “baby steps”, then things such as cells must have been designed.

As with many ID proponents, Dembski’s chief test of whether things could be built gradually, was the bacterial flagellum. He was gracious enough to admit that evolution readily accounts for the gradual construction of many “cellular machines”, however, he asserted, that several objects such as the flagellum have not been accounted for. Dembski fell short of using Behe’s buzzword of “irreducible complexity”. Perhaps this was an attempt to distance himself from Behe’s failure on the stand at Dover.

Dembski explained how the flagellum was a machine in which it had the rotor, drive shaft, mounts to attach it to the cell wall, etc… He was honest enough to mention that a slightly less complex form of the flagellum was the type 3 syringe. Yet at that point, he claimed that since scientists had not laid out a complete evolutionary pathway in which the type 3 syringe had been evolved, then it must be too complex to have evolved (argument from ignorance anyone?).

Additionally, Dembski made the claim that the type 3 syringe had de-evolved from the flagellum. His “proof” was that having the type 3 syringe would be useless unless an organism had a flagellum to propel itself. However, even on a cursory examination, this is a poor argument given that most infectious bacteria and viruses are picked up by the victim making contact. Bacteria don’t need to go hunting when things will inevitably come to them.

Around this time, I came to notice that Dembski had still not made any use of the screen in the background. The CCC had prepared the initial video. This struck me as odd and yet again as if Dembski hadn’t bothered to prepare or put much effort into his talk. Perhaps he thought Kansas was just gullible enough to lap it up without pictures.

At that point, Dembski embarked upon a tangent saying how, if nothing else, Intelligent Design forced “neo-Darwinists” to be honest and account for such things. He then cited a 2001 case in which a scientist had been caught falsifying his evidence. I expected him to also cite the “Piltdown Man” incident in which scientists were caught in creating a false skeleton. I also expected that the recent incident in which a Chinese scientist, researching stem cells, was caught falsifying data. However, Dembski left it at the single case.

However, the important thing to note here is that in all three cases, as well as others, those that have falsified data have always been exposed by other scientists. Thus, saying that Intelligent Design “keeps scientists honest” is another weak argument given that scientists having to compete with each other for grant money will expose each other.

Dembski then quickly returned to his premise saying quickly that evolution was in many cases statistically impossible but would not make an explanation on why.

The next topic Dembski covered was whether or not Intelligent Design was truly “creationism in a cheap/expensive tuxedo”. He stated that creationism starts with a position and then seeks to justify it. Intelligent Design just happens to use the same arguments, and reach many of the same conclusions. It’s also coincidence that ID is widely supported by the “unwashed masses” as opposed to evolution which is upheld by “educated professionals” (his words, not mine). To me, that boils down to ID and creationism being two heads of the same coin in which creationism is a “bottom up” method and ID is “top down”.

Dembski then stated that while opponents of ID argue that it has religious implications, evolution also promotes a religion, namely atheism. To support this argument, he listed several quotes from prominent atheist scientists such as P.Z. Meyers. Yet he conveniently failed to mention that the study of evolution has also lead several scientists in the opposite direction (himself included, if he wasn’t lying earlier when he told the audience that it was these patterns that lead him to his beliefs). Thus, his claim that evolution must be atheistic falls short as well. It’s all about how you want to *gasp* interpret thigns.

Dembski talked in circles for a short time longer but didn’t say anything new. Finally he opened the floor to questions.

The first question was “Exactly what testable and falsifiable hypothesis does Intelligent Design make?” Dembski’s answer was that to disprove ID, evolutionists would have to account for how features such as the flagellum could arise through step-by-step processes. In other words, unless scientists can explain everything, then Intelligent Design is the default answer.

Another notable question was in which a woman asked precisely what evidence was in support of intelligent design (as opposed to just negatives against evolution). Dembski’s initial response was “I thought I’d already stated them but apparently they’ve fallen upon deaf ears.” He then joked that to do so would require a “whole different talk”. Funny, I thought the purpose of this talk was the “case for intelligent design.” From there, he repeated his claim that things were too complex to be the process of evolution and directed the lady in question to read the articles on his website, or perhaps she should buy his book. She then tried to explain that as a biologist she had read his articles and found them devoid of evidence and asked him again to provide some. Instead of answering Dembski brushed her off with a terse “your question is done.”

This refusal to address questions and dance around the actual question characterized the rest of Dembski’s responses with him impolitely demanding that the posers of several more questions state their question immediately without being given a chance to fully explain the context.

So as an overall review:
- Dembski seemed unprepared
- Presented worn arguments
- Presented easily contestable claims
- Either beat around the bush when responding to questions, or refused to answer them outright

It might just be me, but if Dembski is one of ID’s leading movers, I think those that aren’t anti-evolution have little to fear.

Another interesting aspect of this entire event was the response to it. The school newspaper’s headline for the article (which was on page 2 as page 1 was taken up by an article about Dubya visiting nearby college, Kansas University), read “Dembski defends scientific theory”. Apparently they haven’t quite understood that it’s not science. However, their article remained neutral. Similarly the local newspaper (Lawrence Journal World) did not take a position on whether or not Dembski made a convincing argument. The nearby Kansas City Star did not even find the even worth mentioning.

Dembski’s blog repeats the LJW story with a humorous note before it that reads:
In an unsurprising act of cowardice, not a single Darwimpian defender of faith scientist had the balls fiber to stand up to our fearless leader in Kansas yesterday.

Originally, the Campus Crusade for Christ had wanted a debate with Dembski, but no local scientist would agree. Why? Can’t say for sure. Some have speculated that they weren’t about to debate in such a slanted forum as an event hosted by the CCC. However, scientists refused to attend hearings on ID last year because they wanted to make it clear that it wasn’t even worth that much recognition and time. I suspect that’s the same reason. It might also be good to look at Phil Plait’s essay on debating pseudoscientists. Additionally, while Dembki’s compatriots like to shout from the rooftops that scientists won’t debate him, it’s also worth noting that Dembski himself pulled out of a debate that he was already scheduled for at Case Western University against Ken Miller last month.

Thursday, October 04, 2007

Superstition Kills

In July of 2005 in Papua New Guinea, two men decapitate a woman on suspicion of killing their fathers with witchcraft. To rationalists, it's quite sad that people are so unwilling to accept death that they have to hide from it with magic and fairy tales. But when it starts resulting in more lives being taken, it's more than just pathetic; It's downright dangerous.

Meanwhile, the defense council is asking the judge for leniency because they believe in sorcery. While I think they're nuts for believing in it, if they do truly believe, then the two men still acted making an intentional choice for which they should be held accountable.

Tuesday, October 02, 2007

Stellar Evolution: Synthesis of Elements in Stars

It's been awhile since I've said anything on the topic of stellar evolution. In the last post I made on the topic, I promised to discuss the synthesis of heavy elements in stars, where "heavy" to astronomers means anything beyond helium.

The reason I've held off this long is that this month marks the 50 year anniversary of one of the most important papers ever published: "Synthesis of Elements in Stars", by Burbidge, Burbidge, Fowler, and Hoyle (frequently abbreviated BBFH or B2FH).

The Big Bang model is only able to explain the existence of very light elements, such as hydrogen, helium, and trace amounts of lithium, and beryllium. Even if the model didn't predict this, it was apparent that older clusters of stars had less of these heavy elements present in their spectra. As such, it became clear that what astronomy needed was some mechanism to generate heavier elements from lighter ones. This is known as nucleosynthesis.

Thus, the paper asks,
What has been the history of the matter, on which we can make observations, which produce the elements and isotopes of that matter in the abundance distribution which observation yields?
In other words, the goal of the paper was to explain how nature could possibly generate this distribution of elements:

The story we tell in most introductory classes is horribly oversimplified, in some ways, to the point of being outright wrong. What's usually explained is that fusion builds up heavier and heavier elements in the cores of stars. When the star dies, either in a catastrophic supernova or in the slow death into a planetary nebula, those cooked up elements are released into the universe at large.

But there's a few problems with this. One of the most obvious is that either way, the real heavy elements are cooked up in the cores. Unless there's convection, they pretty much stay put. Whether the star explodes or quietly gives off it's out layers, those heavy elements don't do a lot of moving unless convection has brought them to the outer layers of the star.

Even if we assume that some of those heavy elements made it to the outer layers of the stars to be exploded off, or just gently released, there's still another major problem with the case in the former: Supernovae release a lot of energy. Enough energy that they can break up all those heavier nuclei that they just spent all that work making. This is known as photodisintegration.

So as it stands at that point, the only mechanism we have to really get more heavy elements is to build it up in stars, get it to the surface via convection, and then slowly release it after the red giant phase. But since the massive stars (the ones that can build elements much past carbon) explode, this can't account for the chemical abundances we observe! And even if astronomers dishonestly ignored all these little problems, there's still one more: Even in the cores of massive stars, you still don't cook up elements past iron. So where do all the elements heavier than those come from?

What the B2FH paper did, was to emphasize some alternative forms of heavy element generation. And it did so at great length. The B2FH paper is a book in its own right, taking over 100 pages to establish the novel processes that were being put together. (So the Creationist canard that they go to books to get their ideas across because laying the foundations for a good theory takes up too much space is nonsense. If you actually have a good theory, you can get space in journals.)

The two big ones are known as the s process and the r process, which stand for the slow process and the rapid process respectively. As the names suggest, one of the main differences is the time scales on which they occur.

The idea behind both processes is that in the right conditions, you can occasionally have a neutron smash its way into the nucleus of an atom. Sometimes that's not a big deal; It just creates a different isotope of the same element. However, some isotopes are more stable than others. The life of particular isotopes is frequently shown in the wonderfully scary looking chart of the nuclides.

Since I'm not sure how many people are familiar with this chart, I'd better do some explaining. Each column in this table is a particular element. Elements are uniquely defined by the number of protons the specific nucleus contains. The number of neutrons can change without changing the type of element it is. Rather, it just changes the isotope. But as I mentioned before, some isotopes are more stable than others.

In that particular chart, the gray isotopes running pretty much along the center are the stable forms. The further you get from this stable center, the less stable the atom is. If you're not really familiar with all this, you should probably be wondering what I mean by "stable". You can probably figure out that if something is stable, nothing really changes, but if it's unstable, what happens?

The answer is that one of the extra neutrons will undergo what's known as a "beta minus decay" (β). This just means it gives off an electron. But if you're paying attention to your conservation of charge, you'll notice that we had a neutral particle, that just gave off a negatively charged particle, so we're going to need a positive one here somewhere. The answer is that the neutron became a proton (we see the reverse of this when we form neutron stars).

Since we now have another proton, that means instead of just having a different isotope, we now have an entirely different element; one that's one atomic number higher than the previous one.

Depending on how many neutrons are forcing their way in determines which process you're looking at. If the neutron flux is low (say one proton being captured per nuclei per ~10,000 years), then the chemical evolution is driven by the s-process. If it's high, then it's the r process.

Let's look at an example of how this works for the s process first:

First, we'll start with 109Ag (silver). Smack it with an extra neutron and it changes to 110Ag. But, you'll notice that the 110Ag doesn't last very long. According to the color key, it will decay in sometime less than a few years. Unless it's in some pretty special circumstance, it's not going to pick up another neutron before it decays. So it undergoes a beta decay and gets bumped up to 110Cd. Most of the isotopes up from there are pretty stable until it hits 115Cd. Then, again, it undergoes a beta decay and becomes 115In. The process continues on, building heavier elements as it goes.

So the next question is, where can things like this happen? Where are protons energetic enough and prevalent enough to force their way into a nucleus?

It turns out that during the red giant phase of a star's life, the conditions are just right in the outer layers of stars for this process to occur. Additionally, nebulae can be bombarded with neutrons as well, allowing this process to occur there as well. Slowly but surely, heavy elements are built up.

But there's some elements that the s process can't account for. For the sake of clarity, let's look at another part of that nuclide chart.

On this, you'll notice that in the column for Pd, there's a particular isotope (109Pd) that doesn't last very long. If we got there by the s process, it would decay to that 109Ag we started with earlier before being able to be transformed into the stable 110Pd. Thus, if there's any 110Pd in nature, the s process certainly can't account for it.

This is where the r process comes in. For the s process, the flux of neutrons is relatively low (<1011 neutrons per cm2 per second). Meanwhile, for the r process, we're talking about instances when the flux is more like 1022 neutrons per cm2 per second!

Thus, even for isotopes that don't last for more than a fraction of a second, the rate at which they're being bombarded is so high, that they can get stuck full of neutrons before they can decay. Thus, the element runs all the way down the column until it's so full of neutrons that it physically can't hold any more and any additional ones "drip" off.

Since it's impossible to keep up that high of a flux of neutrons forever, the rate will eventually die off and the decay process can begin. It takes elements diagonally up and to the right (the way this diagram is drawn) until it finds a stable element. The diagram for that looks something like this:

Thus, the r process can build up the heavier isotopes that the s process can't account for. The s process can build up the abundances near the inner part of the nuclide chart whereas the r process takes care of the outer, heavier isotopes.

So where in the universe do we find ridiculously high neutron fluxes? In supernovae! While the initial energy release can destroy heavy elements, the neutron flux remains sufficiently high for a good while longer and can build them right back up to even higher atomic numbers than the core was able to fuse in the first place.

But do these models hold up to observation? Sure they do. Both processes predict specific relative abundances. The distributions predicted match the observed abundances extremely well.

The B2FH paper laid the foundation for stellar nucleosynthesis 50 years ago at this point and has been well established for a long time now. But of course, dishonest creationists like Kent Hovind love to show that they're more closely related to ostriches than apes when they bury their heads in the sand and ask questions like this: