8/18/2006

Of Wanderers and Wonderers

Today is a good day for science.

Recently, I have been inspired by news that astronomers are currently convening in Prague to decide the fate of Pluto, the black sheep of our solar system. This "plucky" little spheroid (yes, one of the "journalists" covering this story used that adjective in describing some elementary school children's attempts to save its historical status) has, for decades now, been the recipient of the astronomical equivalent of affirmative action.

But discovery of other objects in the solar system of comparable size and orbit have called Pluto's status into question. For scientists to be consistent, they would have to allow Pluto's moon Charon, the heretofore-asteroid Ceres, and the newly discovered celestial body nicknamed "Xena" into the planet club. Moreover, dozens or perhaps even hundreds of roughly spherical objects orbiting the sun may be candidates for entry.

Reading about this fascinating shift in long-established facts has reminded me of the wonder I experienced in my youth regarding what I thought at the time was God's creation (or, more accurately, just God; I was pretty pantheistic). About the time of my sophomore year in high school, I really got into cosmology and astrophysics. I thought then that I would surely become some sort of scientist, a geneticist if not a physicist (I was taking biology at the time).

I read popular works, primarily by Stephen Hawking. I read the original version of A Brief History of Time, as well as the illustrated version, and I even made my parents play lectures of his on tape (in his robotic voice and everything!) during at least one family vacation. I saw in a bookstore the other day that he has a new illustrated tome entitled The Universe in a Nutshell which purports to be an update of that first popular book which I so enjoyed.

I see these sorts of adolescent ruminations on the nature of reality as my first stirrings of philosophical interest. My interests in science have shifted--towards evolutionary theory and neuroscience more than anything--but they never completely left me.

In fact, I could quite easily see myself in graduate school for science, were it not for the fact that experimental work never appealed to me. (Also, even though I am fortunate to be mathematically talented, I never really liked the more advanced math that I studied.) I'm too much of a big picture thinker; I wouldn't be satisfied chipping away at one small corner of the universe when there's so much out there that's exciting.

But, as I've said, my interest in cosmology has been rekindled, and I've been spending (too) much time recently perusing Wikipedia. I have to say, it is a fantastic source (as far as I can discern) for popular discussions of theoretical physics, advanced mathematics, and high-concept science-fiction.

I'm feeling lazy, otherwise I'd include links, but I started off looking at Dyson spheres, stellar engines, the Kardashev civilization scale, the anthropic principle, ecumenopoleis (plural form of ecumenopolis, or world-city), and cosmological evolution (what you might call Darwinism for universes). I swear, though, I could spend days reading about these things. They're utterly fascinating, truly a testament to the power of the human imagination and the sublime beauty of our universe.

I think it's no coincidence that I find Spinoza so compelling, given these sensibilities. Even though he is an amazing thinker in terms of human psychology, ethics, and politics, Spinoza is also a big picture thinker. I find some fascinating parallels between Book I of the Ethics and ideas like the infinite universes hypothesis and the anthropic principle. This is huge stuff--I mean, we're talking bigger-than-the-universe stuff.

Consider the following. It's a given that intelligent life is an extremely improbable phenomenon. Given enough time and space, it's bound to happen somewhere in a universe, but only if that universe falls within specific parameters, having certain fixed cosmological constants. Because of how rare it is, it would seem to us that (excluding the possibility of intelligent designer(s), whose existence would itself be even less probable than that of a universe capable of supporting some kind of intelligent life) it's unlikely to arise if only one universe existed. In other words, the fact that we exist seems to lend credence to something like the infinite universes hypothesis.

But, as it turns out, this kind of reasoning is an instance of the inverse gambler's fallacy! As you may know, the gambler's fallacy is this idea that if you've been, say, playing roulette for a long time and 17 hasn't come up yet, that it's due to show up on this particular spin. The error here is that dice (and roulette wheels) have no memory. On any given trial, it's just as likely that 17 will come up if the last 100 spins have not landed there as it would be if say 50 of the past 100 had (improbably) landed on 17.

The inverse of this, also a fallacy, is to think that the occurrence of something improbable means a long history of unsuccessful attempts. So, say I go to a casino and play the slot machine once, hitting triple-7 and winning the big jackpot. I then ask you, is it more likely that this is an old machine that has had many losers before or that it's a brand new machine which had never been used before? We'd be inclined to suppose the former, but unjustifiably so. The probably of hitting 777 on spin #1 is equal to that of hitting 777 on spin #1,000,000.

What does this mean for the universe? Well, the likelihood that life will arise in this universe does not change even if there are millions of non-life-supporting universes "out there" (assuming that universes are closed systems that don't interfere with each other). If this reasoning is correct then, from our perspective, it is no more rational to believe that there are infinitely many universes than to believe there is just one--it's merely an aesthetic preference. That's just so counterintuitive!

14 comments:

island said...

The whole argument is lame. The configuration of the universe follows the least action principle via whatever constraint is imposed by the *good physical reason* why no practical model of turbulence-driven structuring has ever been derived.

Figure out how the evolution of the universe still manages to follow the least action principle, in dramatic contrast to the normal expectation, and you will then know why there is only one possible configuration, (without infinite need for excuses why they can't do physics)... ;)

You will also then know the real reason for the anthropic principle, rather than some hype about an infinite potential that is neither necessary nor justified.

That crap isn't science, it is scientist's greatest cop-out on causality... yet.

Richard said...

I've a response here.

island said...

Well, I don't see it as a response to anything that I said, but okay.

specter_of_spinoza said...

I'm afraid I don't quite follow your argument, island. I'm not familiar with all the technical terms.

I'm just a philosopher after all, and while I do know more math and science than some of my colleagues, I'm far from being an expert--I mean, why else would I be looking on Wikipedia? Incidentally, here is the link to the article whence I got the argument.

In any case, I'm willing to admit that I'm wrong. I think I at least follow Richard's argument (I think he was responding just to me) and it seems cogent.

island said...

Yes, you are correctly in context with "something"... I was simply saying that the whole problem only came to be in the first place, because nobody has ever managed to come up with a "causality responsible" explanation for why the big bang produced the structure that we ended up with. All "normal" attempts fail miserably.

There is an anthropic-constraint feature that hints at what this is though. Figure out how and why we are relevant to the physics of the universe, and you'll know why there is no need for the argument that you are currently engaged in.

Good luck with your philosophy, but bear in mind that a good understanding of nature is necessary so that that you don't project philosophical fantasies.

specter_of_spinoza said...

Don't worry, I'm not constructing castles in the sky.

Nevertheless, I'd be careful not to pretend that physics has the final say. I think a lot of the most interesting cosmological questions we have are quite possibly unanswerable. There's no guarantee of a grand unified theory of everything.

Don't get me wrong, I have tremendous respect and admiration for the physical sciences. But I see philosophy (and other humanistic disciplines) as having a value independent of them.

What's the point of having knowledge if you don't know what to do with it? Equations can't tell us how to live our lives.

island said...

No?... Don't be so sure. Did you know that claim depends entirely on which cosmological principle is in effect, and in what universe?... and your statement is absolutely false if LaPlace's Demon is in effect in a finite universe, which I have good reason to believe is indeed the case.

Again, figure out how and why we are relevant to the physics of the universe, and you'll know why there is no need for the argument that you are currently engaged in.

Jeff said...

As far as I can gather from his cryptic posts, "island" is indeed marooned on a mechanistic island which the scientific mainstream left about a hundred years ago.

First:
To my thinking, Heisenberg showed that the anthropic principle could never be reconciled with LaPlace's Demon, (if this is your project) as our knowledge of physical reality always creates unforeseen consequences, ruling out the possibility of the type of all-knowing intellect which LaPlace's Demon assumes.

Second:
You write, "Figure out how the evolution of the universe still manages to follow the least action principle, in dramatic contrast to the normal expectation, and you will then know why there is only one possible configuration..."
The least action principle is not falsifiable, and your claim that the universe somehow "follows" this principle is an example of the kind of vicious intellectualism that is antithetical to the scientific spirit. You've got it backwards--the least action principle is useful in explaining many phenomena in the universe (those phenomena which can be explained by classical mechanics), but it cannot explain other phenomena (such as phenomena that have been observed on the quantum scale, e.g. quantum foam). To say that the universe follows this model is to exclude empirical evidence on the basis of an intellectual and mathematical idea.

Perhaps another of LaPlace's principles is in order here: "The weight of evidence for an extraordinary claim must be proportioned to its strangeness." Where is your evidence, island?

island said...

As far as I can tell from his popularized science mentality, Jeff seems to think that anything has been settled. He must think that he or moden science has the ToE or even a valid theory of quantum gravity in their back pocket. No, but it's just around the corner, right? So string theory is the final end-all for science that allows philosophers to make up any reality that they want to and call it home.

That must be why books like these have just started hitting the shelves, in preparation for the much predicted failure of the large hadron collider to produce evidence that will save his meaninless world-view:

Not Even Wrong: The Failure of String Theory and the Continuing Challenge to Unify the Laws of Physics...

The Trouble With Physics: The Rise of String Theory, The Fall of a Science, and What Comes Next".

Tell me, Jeff, where does uncertainty fit into John Wheelers MODERN interpretation of the anthropic physics?... hmmmmm? Better yet, tell me where uncertainty fits into any interpretation that derives that we are not here by accident. Can you do that for me Jeff? After all, popularized claims deserve some kind of equally lame philosophical rationalization for how evidence that we're not here by accident can be convoluted into meaning exactly the opposite via "uncertainty" and infinities.

Lame.

Secondly, Jeff appears to be throwing up a bluff that he isn't going to be able to judge for himself, (tho I could be wrong), so the question becomes one of whether Jeff will make an honest admission when he sees very simple, (not extraordinary) physics that vindicates Einstein until someone proves him wrong?

Will you do that, Jeff?

Can you do that, Jeff?

... or will you start making lame appeals to authority, while redirecting your argument somewhere else?

1) In Einstein's static model, G = 0 when there is no matter density.

He brought in the cosmological constant to counterbalance the runaway recollapse effect that occurs in this model because we do have matter, but in order to get rho>0 out of Einstein's matter-less spacetime structure, you have to condense the matter density from the zero pressure metric, and in doing so the pressure of the vacuum necessarily becomes less than zero, P less than 0, which causes expansion, while holding the universe stable and near-perfectly-"flat". (*Note that the background changes everytime that you do this.) It becomes evident from this "new-light" that most natural way to create new matter in Einstein's model, ("the most compatible with the spirit of general relativity"), also holds it flat and stable, (instability being the only reason that he abandoned it), so any other conclusions that have been made since Einstein abandoned his finite universe without this knowledge are therefore subject to suspect review, especially the reinterprtation of the negative energy states.

http://arxiv.org/abs/hep-th/0401208

2) Add the physics for the observed universe that produces the anthropic principle to this finite, closed, bounded structure and what you get is a very strong statement about a biocentric structure that "evolves" perpetually forward to higher orders of entropic efficiency.

What's I going to be, Jeff?

1) You admit from very simple and obvious evidence that I have a valid scientific point.

2) You remain in willful denial and start making appeals to higher authority, because you can't even judge the validity of the most simple physics that you'll ever see.

Your move.

island said...

The least action principle is not falsifiable

Jeff also seems to think that his inabilty to provide a single case where the least action principle doesn't hold means that it isn't falsifiable.

Which really means that Jeff has no idea what Jeff means, but he knows how to throw-out crap that sounds good.

Jeff said...

You're right, Island. I'm out of my league here. I suppose, given the brevity of your posts and my unfamiliarity with the research, I took you to be arguing for something you were not arguing for. Sorry about that.

As for the falsifiability claim, you are also right--the least action principle is falsifiable.

So, nothing left but to admit my response was mostly a knee-jerk attempt to defend Specter from what I saw as a gratuitous attack.

Cheers!

island said...

Well, I'm sorry too, because, on reading back, I realized that I probably took more offense than I should have to what you said.

I may fall over dead from your admission though. You truly appear to be an honest an honerable person.

Again, my apologies if I over-reacted.

specter_of_spinoza said...

Yes, island, Jeff and I are both pretty good about admitting what we don't know. Honestly, a philosopher who hasn't learned the lesson of Socratic wisdom is often not worth your time. Although, I do agree with Jeff (in a previous discussion we've had) that authentic philosophers must begin by killing Socrates.

In any case, I'll be honest and say I haven't followed you from your first comment. I actually wish I had more physics background, because I find the subject intensely interesting.

Do you have any recommendations for novices like myself, books that could provide background for an educated layperson? My astrophysics knowledge has come primarily from Hawkings' popular books, but I don't know how representative he is of the field. Then there's stuff from Wikipedia, but I know that's very questionable in its reliability.

island said...

Actually, Wikipedia is "typically" an excellent source, except there are some struggles that go on when there are "other" factors that are motivating people to try to put a slant on the given subject. They do a lot to try to mediate and then fairly represent the facts. Every change is recorded and can easily be reversed if somebody screws something up. They have a notification system that alerts when changes get made, and they have people that are designated to monitor changes.

Unfortunately, the anthropic principle might be the worst case of all for ideolgically motivated abuse. I know this because I constantly fight this battle against both sides of the ideological spectrum where the AP is concerned.

If you're really that interested in learning physics, rather than limiting yourself to popular beliefs and misleading cosmological generalizations, then you should make an honest effort study the fundamentals, especially of Relativity, and there are even some tutorials on the net for that. Look for John Baez name on just about any physics topic for clear concise conservative explanations, except for maybe the anthropic principle.

This book is the kind of stuff is commonly recommended, and a lot of these are too difficult at first, but you have work for the kind of understanding that you need to have to avoid the subtle traps that lie everywhere. You don't have to understand everything, but you do have to study hard just to learn the proper context of language in whatever model, as you've noted.

http://www.amazon.com/gp/product/0716703440/002-2489798-0406412?v=glance&n=283155

I've been studying physics for about 20 years, the anthropic principle exclusively for about four years. There is so much more to it than anybody realizes yet, mostly because they don't bother to take an honest look for the reasons that I've previously given.

My understanding and feeling of purposeful kinship to nature never fit with the world-view of the scientists that I learned from, and I could never understand it, until I found the anthropic principle, and I knew instantly why.

Some of the most intelligent physicists that I know haven't got a clue because they don't want to believe that there can be higher teleologically manifested purpose in nature, even if it's just thermodynamic intrinsic finality, and even when faced with very hard evidence like I can give.

It's extremely frustrating, but I am sane and confident when I say that a true anthropic cosmolgical principle means everything to all sides including the greeks!!

Good luck