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:

Building Double Standards

In Maryland, residents are trying to hinder the arrival of a Muslim group. The group is looking to build Muslim mosques and convetion centers in the area, but those opposed to it cite "traffic or loss of tax revenues" as reasons to reject the proposal.

But there seems to be a rather large double standard. Last fall, I commented on a Texas town in which churches had grabbed so much land and made it untaxable that it was stunting business growth, and forcing the government to raise taxes elsewhere to make up for lost revenue. In this case, where there was a legitimate concern, nothing was done to hault the exansion of Christian churches. Yet when a single Muslim church seeks land, it's time to use land taxes as a means of rejection.

From the comments of the citizens, though, the reason for the double standard seems quite obvious: Ignorance.

One citizen was quoted saying, "I don’t know that much about Muslims, but I understand they want to take over the world and want us all dead."

Sounds like someone's taking a page directly out of the Bush administration's playbook.

The Brits Get It

Despite the shrill whines of the Creationists, rejecting their nonsense has nothing to do with disproving God, or trying to get ourselves out of some sort of moral obligation.

What it is about is intellectual honesty. As such, it's horribly dishonest to pretend that Creationism is a legitimate scientific theory and that it belongs in classrooms.

But given that science cannot comment on whether or not a supernatural realm exists, and if it does, what could be in it, we must be careful not to overextend the role of science.

Realizing this, teachers in the UK have been instructed that Creationism can be discussed in classrooms, but it must be made clear that it has "no underpinning scientific principles".

That sums it up quite nicely to me.

Monday, October 01, 2007

Conversion Factors

Units are nifty. Most non-science people are rather frustrated by them, but typically, it's a very nice, quick way to check equations to make sure they'll actually give you the sort of quantity you're looking for. After all, you don't want a distance coming out with seconds as the unit. Rather, you'd want something in meters, or parsecs, or furlongs, etc....

In astronomy, we tend to switch between units quite often. Meters are perfectly fine for describing diameters of planets, but aren't ideal for the size of solar systems. For that we use Astronomical Units (AU). Those work great on that scale, but fall short (har har) for sizes of galaxies. Lightyears or parsecs are much better there. For cosmological distances, we like megaparsecs.

Quite often in classes, professors like to make sure you're paying attention to your units and will give you something in a unit that needs to be converted to something else before it will cancel with the units of a particular universal constant. Most of us students that have been doing this for awhile realized that having to look up the conversion factor and do the conversion by hand gets tedious.

Fortunately, the great Google can do every unit conversion known to man. Need to know how many megaparsecs 245 AU is? Just type in "245 AU to megaparsec" and BAM! Google spits out your answer: "245 Astronomical Units = 1.18779352 × 10-9 megaParsec". Nifty. Now let's try to figure out what the hell the rest of this problem this professor is asking us actually means...

Pretty straightforward. But Google sure does know some weird conversions. I mean, who the hell asks for the "number of horns on a unicorn acre in tea spoons per light year"?