Total Drek

Or, the thoughts of several frustrated intellectuals on Sociology, Gaming, Science, Politics, Science Fiction, Religion, and whatever the hell else strikes their fancy. There is absolutely no reason why you should read this blog. None. Seriously. Go hit your back button. It's up in the upper left-hand corner of your browser... it says "Back." Don't say we didn't warn you.

Tuesday, March 11, 2008

Throwing them a bone.

Regular readers of this blog know that I have a certian penchant for clashing with creationists. This isn't so much because I think creationism is a vapid philosophy* or that I think creationists are stupid** but, rather, because there's this nasty tendency for creationism to disguise itself as science. This strategy tends to annoy me a little.

One of the problems with keeping tabs on creationist rhetoric, however, is that you start to learn all of the standard arguments. There's the argument about the second law of thermodynamics, the argument about carbon dating, the argument about comets, about the complextity of life.... yawn. I've seen pretty much all of the common creationist arguments, I've seen them reduced to smoking craters by authorities whose rhetorical deficiencies are more than made up for by their logical skill,*** and so I get awfully bored when I run into those same arguments all over again. Yet, despite my boredom, the same craptacular arguments keep coming up.

So, today we're going to try something a little different: I'm going to make a suggestion to the wacky creationsits out there as to some new material. Now, keep in mind that I don't personally think that this is a terribly strong argument in favor of creationism but then I have yet to see an argument for creationism I consider "strong." Mostly I suggest it because if the creationism community could take my suggestion, warp it beyond recognition with their usual rhetorical voo-doo, and then bring it back I'd have a much more entertaining day.

Now, in order to understand this suggestion we need to talk about something: antimatter. For those of you who don't spend as much time on particle physics as I do,**** an anti-particle is essentially identical to a standard particle but has the opposite charge. So if a proton has mass x and a positive charge, then an anti-proton has mass x and a negative charge. Likewise if an electron has mass y and a negative charge then an anti-electron (i.e. a positron) has mass y and a positive charge. Finally, believe it or not, if a neutron has mass z and a neutral charge then an anti-neutron has mass z and a neutral charge- but is composed of oppositely oriented quarks. Antimatter is well-known for being a ferociously powerful source of energy. This is because, quite simply, when a particle and its anti-particle come into contact they mutually annihilate or convert each other into energy. Now, using Einstein's famous E=MC^2 equation we can find that, really and truly, this direct mass-to-energy conversion yields a crapload of juice and, thus, a matter-antimatter annihilation is one of the most energy potent reactions known. Producing antimatter here on Earth has proven to be extremely expensive but we can do it and even utilize the unique properties of antimatter for some very interesting applications. So, put simply, the existence of antimatter and its place in the standard model of physics is well-understood and experimentally validated.

What's less often talked about, however, is that antimatter is equivalent to normal matter in another way: it can form atoms and molecules. Those anti-protons, anti-neutrons and positrons can form atoms the same way normal protons, neutrons and electrons would. Even better, they can assemble into complex molecules, even organic molecules. In essence, all the chemistry that works with normal matter should also work with antimatter. Finally, what is least often discussed is that while we understand the processes that give rise to anti-particles, we also understand that they generally give rise to equal amounts of matter and antimatter. Now, consider that for a moment: if we manage to generate the energy levels necessary to cause radiation to condense into matter it tends to do so in matched particle/anti-particle pairs. If you make a positron you usually also end up making an electron as well. Why is this an issue? Well, it wouldn't be except that according to our current understanding of physics this should have been the case during the big bang. That is to say, the big bang should have produced equal amounts of matter and antimatter which, having opposite charges, should have been attracted to each other, annihilated, and left the universe as an expanding soup of radiation. As some of you might have noticed, this does not appear to be the case and, instead, the universe contains large quantities***** of matter and virtually no detectable antimatter. This is a long-standing problem for modern physics, known as baryon asymmetry, and forms the core of the bone that I am throwing to creationists.

You see, creationism sometimes invokes what is known as the "fine tuning" argument. This more or less boils down to an assertion that, since different physical constants would prohibit the emergence of human life, the universe must have been designed for us. This argument seems to me to be, in a word, stupid. The simple truth is that any organism smart enough to ask the question in the first place will have to be adapted to its environment. It will, therefore, ask how it is that the universe appears so well-suited to it without ever wondering if small changes would make that universe even MORE suited to life than it is now. What I propose, however, is that creationism tackle the baryon asymmetry issue more directly and just claim that the reason why there is more matter than antimatter is because god wanted there to be more matter than antimatter. This is, after all, an unsolved problem in physics: our models suggest the universe should be equal parts matter/antimatter yet, really, that doesn't seem to be the case. Unlike typical fine tuning arguments this one is also relatively difficult to dismiss via reference to the anthropic principle.

"But Drek!" you ask, "Is it really a good idea to give arguments to creationists?"

Normally, no, but if creationists actually go for this one I don't think anyone needs to worry. Partly this is because I'm an egotistical bastard but there are more compelling reasons as well. There are, for example, a number of proposed solutions to the problem and, in any case, estimates suggest that the imbalance between matter and antimatter to be explained is very small (on the order of one extra matter particle for every 10 billion pairs of matter/antimatter particles). It would appear that we are composed of the fractional unburned remnant of the titanic matter/antimatter annihilation that populated the beginning of the universe. Besides which, we have recently detected, and partially explained, the existence of a large cloud of positrons near the core of our own galaxy. This provides the first observational evidence of a substantial quantity of antimatter somewhere in the universe****** and helps validate our current model of particle physics. This gives me substantial confidence that, in time, baryon asymmetry will be fully explained. Besides, I actually doubt that those most interested in pushing creationism will find this argument appealing. While this strategy does pose more of a problem for modern science, it also requires that the creationists accept large portions of the standard model of physics as well as the titanic age of the universe. After all, if the universe isn't ancient and physics has it wrong, then there is no baryon asymmetry problem to be explained, is there? This argument is, therefore, more or less a trojan horse: if creationists try to use it, they end up losing most of their other claims right away. I like them odds.

In the meantime, however, by harping on this not only could the creationists help motivate real scientists to figure the problem out, but could also provide the rest of us with a lot more entertainment. It's a win-win folks.

* I mean, I do think it's a vapid philosophy, but that isn't the point.

** Actually, I do not think most creationists are stupid. I think that a number of them are highly intelligent and the remainder simply believe what they were taught to believe, the same as most everyone else.

*** Actually, there's an interesting article from 1985 in the Review of Religious Research ("Processes of Persuasion: The Case of Creation Science" Richard Stempien and Sarah Coleman. 27(2): 169-177) that finds that pro-evolution speakers during the creation science debacle preferred to educate their audience about evolutionary theory while their opposition, the creation "scientists," preferred to try to define the terms of the debate in a way that would favor them. Really, in total, the research found that academics generally had a hard time in these debates not becuase they didn't make sense but, rather, because they weren't experienced in playing to the crowd.

**** I'm forced to wonder sometimes how I manage to sleep. Then again, since I can recall several dreams in which I spent a considerable amount of time working on equations, there may be very little difference between my awake and sleeping states.

***** Well, "large quantities" from a certain perspective. The universe is dominated by open space and, secondarily, by energy. Matter is the equivalent of that thin scum that forms on the top of pudding. Mmmmmmm pudding.

****** Don't worry about meeting your death screaming in a matter/antimatter explosion: matter and antimatter is almost always produced in equal quantities. As such, given that we now have such a significant asymmetry in favor of matter, it's unlikely that any natural processes we now understand could produce enough antimatter to make a dent in the quantity of matter the universe contains. Also: we have yet to detect any natural anti-particles larger than a positron.

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Blogger Marf said...

Well, it's my understanding that there is no anti-photon (light particle). So it would be extremely difficult to tell the difference between light produced by matter or antimatter.

So in my opinion, there could be entire galaxies out there made from antimatter, perhaps even half the galaxies. (thus keeping the balance)

Also, your point about opposites attract: Opposite charges attract, like charges repel. So a proton (+ charge) would still repel a positron (also + charge). So matter and antimatter wouldn't always attract each other.

Let's take a common hydrogen atom: 1 proton and 1 electron; net charge 0. Now let's take its antimatter equivalent (1 antiproton and 1 positron), that would also have a net charge of 0. So why would matter and antimatter attract each other any more than regular matter and regular matter?

I think in the early stages of the universe, most of the matter and antimatter did annihilate each other. What's left is the sort-of unburned fuel that got thrown free from the blast.

Tuesday, March 11, 2008 1:53:00 PM  
Blogger Drek said...

Marf: Your comment is really interesting and I've been thinking about it. The mechanism you propose (i.e. that anti-particles would form neutrally-charged anti-atoms and, thus, would become disinclined to annihilate with matter) is not one I've heard suggested before. My response to it is on two levels.

The first is that, from what I can tell, anti-hydrogen does annihilate with regular matter fairly readily. This necessitates the use of magnetic traps when we manufacture anti-hydrogen and so, while I don't claim to understand exactly why, I don't think we can be confident assuming that matter and anti-matter can co-exist stably.

My second reaction is that, if we suppose that anti-matter exists in measurable quantities in the universe forming stars, galaxies, etc., then a significant portion of it must be in an ionized form and, therefore, not charge neutral. Hell, the solar wind from a star composed of anti-matter would be a veritable deluge of charged anti-particles. This, in turn, means that we should oberve a significant number of annihilation events with regular matter unless the matter and anti-matter are extremely widely separated and have been for some time. I'm not sure that's any less fundamental a physical conundrum then baryon asymmetry itself.

Again, I think you raise a really, really interesting point but I'm not sure that it provides a good reason to suspect that anti-matter does exist in major quantities somewhere in the universe.

Wednesday, March 12, 2008 9:42:00 AM  
Blogger Marf said...

I didn't mean to say that hydrogen and anti-hydrogen wouldn't annihilate each other if they came into contact. I'm just saying they wouldn't necessarily attract each other.

If you think back to the beginning, everything was relatively close. So clumps of regular matter and clumps of antimatter were not really that far apart. Anything that wasn't clumped with like-matter and was a mix got annihilated. Over time, those clumps left over became clusters of galaxies. (or perhaps even superclusters)

So although our local group may be all the same type of matter, another cluster may be antimatter.

Over time everything has drifted so far apart that you don't get matter-antimatter reactions between groups of galaxies.

Now, how would clumps even form? Why wouldn't everything be perfectly uniform? I suspect quantum uncertainty played a role. It's like flipping a coin, sometimes you get several heads in a row. So some of the matter particles flew off in the same direction and clumped together, same with anti-matter particles.

That's my thoughts anyway...

Wednesday, March 12, 2008 3:08:00 PM  

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