It was a matter of simple osmosis
That brought our words to life.
I first found a trail of them,
Busy verbs and prepositions,
Searching for crumbs of information.
Every book in my library
Has become a hive
Each an antagonist to the others.
Darwin feuds with Freud.
Mein Kampf struggles with Nietzsche.
The science-fiction section
Has become a technological dystopia.
There are battles biblical and mythopoetic
With carnage literal and metaphoric.
The floor is littered with letters
And suffixes torn from their roots.
At first I tried to intercede,
But I quickly learned
That words can sting.
Thursday, July 29, 2004
It was a matter of simple osmosis
Tuesday, July 27, 2004
Like a lot of geeks, I used to play Dungeons and Dragons. When I was playing, back in the 80's, various parental and religious groups took exception to the game accusing it of such things as causing teenages to kill themselves and to get involved with the Occult. For those of us playing the game, these claims seemed awfully silly and overblown.
The comedy group The Dead Alewives have perfectly captured this with a clever little skit called, simply, "Dungeons and Dragons". I'm going to link to two versions. The first version is to the original audio-only version of the skit. The second, called Summoner Geeks, is an animation of the first using figures from a video game called Summoners.
Sunday, July 25, 2004
This is part three of a four part essay. In this part I shall discuss the prospects of interstellar travel and the challenges that face it.
Let us be optimistic and suppose that there are a thousand intelligences in the Milky Way. This should place us within a thousand light years of our nearest neighbor. Let us further suppose that some oracle gave us the precise location of our neighbor. Being good neighbors, we shall desire to say hello.
How shall we do this?
A thousand light years is infinitesimal against the span of the cosmos – it's not even significant on a galactic scale – but it is a daunting gap all the same. For those of us raised on a diet of science fiction, the obvious solution is that we would just hop on a spaceship and go visit them. Unfortunately, there's a number of problems with this.
The most obvious problem is the speed of light. At the very best, it would take a millennium to reach them. Perhaps, instead of just racing off towards them, we'd be better off taking a few hundred years to develop some method of traveling faster than light.
What I am about to say is going to meet with reactions of denial. I must say it never the less: in all probability, there is no way to travel faster than light.
What heresy! What arrogance! Where there's a will, there's a way! Nothing is impossible!
There is a general feeling that, while science may be good at providing solutions to problem, anything we know now can be proven wrong at some point in the future. To a degree, this is true, however there is wrong and there is wrong. The late Isaac Asimov addressed this is a beautiful essay called "The Relativity of Wrong". The point of the essay was to demonstrate that although science works by replacing incorrect theories with newer theories, the general trend of science is cumulative and not revolutionary.
To illustrate what this means, let's take a quick look at Newton's Theory of Universal Gravitation. Newton's theory makes some very specific predictions about the motions of the planets. Unfortunately, it's "wrong". For one thing, it fails to properly predict the orbit of Mercury. Einstein's Theory of Relativity "replaced" Newton's and managed, among other things, to make proper predictions with respect to Mercury's orbit.
Notice the scare quotes around "wrong" and "replaced"? They are there for a reason. Newton's theory was incorrect but the correction that the Theory of Relativity applies to Newtonian predictions is very, very slight. While the Relativistic model does have more explanatory power, its utility is limited to cases of extreme velocities, accelerations, masses and densities. If you were to go into close orbit around a black hole, you'd need to apply relativistic equations to your situation. If you are "merely" launching a probe on a ballistic journey to Pluto, however, all you need is Newton.
Asimov compares this to models of the shape of the Earth. The earliest model of a flat Earth was wrong (although, strictly speaking, it was only off by a few degrees of curvature). The subsequent model of a spherical earth was also wrong because the Earth is not perfectly spherical. Currently, the Earth is described as an oblate spheroid (meaning a slightly flattened sphere). With better topographic surveys, the shape of the Earth will become more and more precisely described with each new description replacing one that is, technically, wrong. Each new description, however, is only a correction to the previous ones. The overall shape of the Earth is well understood. If someone says that the Earth is shaped by a ball, we know that it would be pedantic to insist that they are wrong in saying so.
The Theory of Relativity, which tells us that object or source of information can travel faster than the speed of light, is the most thoroughly tested theory in the history of science. Even the most precise experiments using the most sensitive instruments have failed to detect even the slightest deviation from theory. Given that the theory is approaching its hundredth anniversary, it is an understatement to say that this is impressive.
We do know that the Theory of Relativity is incomplete. We know this because it is incompatible with Quantum Mechanics (which also has an amazing record of experimental verification). The quest to come up with a theory that can unify the quantum and the relativistic realms is the holy grail of physics. The incompatibility of the two theories, however, only shows up in the most extreme possible conditions -- the sort of conditions that you'd find at the hearts' of black holes.
Might an FTL (faster than light) drive pop out of a Unified Equation? It's possible but it's unlikely. It would not be quite like having advanced satellite imagery prove that the Earth is actually a cube and not a spheroid, but it's certainly nearer to that side of the analogy. It would be a delight if the laws of physics did let us, after all, make allowances for FTL, but we shouldn't pin our hopes on it.
Perhaps it's just as well. If FTL did turn out to be possible, it would only make the Fermi Paradox that much more baffling. Rather than having life spread through the galaxy in a cosmic instant, we should expect it to spread through the galaxy in a merely historical instant. The existence of FTL would make it that much more likely that intelligence is truly rare.
Very well, let us suppose that we can't reach our neighbors with some sort of super-science warp drive. Perhaps we can go the long way around. In fact, relativity does offer a kind of solution. As one edges towards the speed of light (never reaching it), time begins to dilate. One second of your personal time could equal a year of time to an Earthbound observer. So long as a daring astronaut was willing to lose all of his loved ones and everything he knew to the dust of history, he could take a one way journey into the future in order to meet our distant neighbors.
Although the Theory of Relativity doesn't forbid such trips, there are two things that do stand in opposition: mass and energy. In order to make a spaceship move, you need reaction mass. Reaction mass is, quite literally, stuff that you throw out in one direction in order to move in the other. The bigger the mass you toss out, and the fast you toss it, the faster you move. Unfortunately, in order to move very far, you need to have a lot of reaction mass. The thing about reaction mass is that it is, in fact, mass. The more mass you have, the slower you accelerate.
It's a diabolical relationship. Let's say you have a ship with a thousand gallons of rocket fuel. If you burn up all your fuel, you can get up to a thousand miles per hour. Although that's pretty fast, you want to go twice as fast, so you pump your ship us with two thousand gallons. Unfortunately, now you're much heavier than you were before (or massive, if you want to be technical). Instead of doubling your speed, you've only gotten part way to your goal. So we add more fuel. But now we have more mass. The more velocity you want, the more fuel you have to add and less you get back from the effort. The mass requirements quickly exponentiate.
I have seen estimates that suggest that using current propellants, you'd have to have a fuel tank the size of the solar system merely to get to the nearest star in a reasonable amount of time. The only way around that is to find some way to get more bang for your buck. That's where energy comes in. Some fuels are more energetic than others. There's a reason that we don't gas up the space shuttle with ethanol. It wouldn't delivery nearly enough energy to get the shuttle into orbit. Instead we use fuels that have a high energy density. You're going to get a lot more energy out of a gallon of liquid oxygen than you would a gallon of gasoline.
In order to reach relativistic velocities (and to decelerate from them – it doesn't do you any good if you can't slow yourself down), rocket fuels aren't going to do the trick. There is, unfortunately, a maximum amount of energy you can get out of a given quantity of reaction mass. This is defined by the famous equation E=mc2. Matter and energy are basically two aspects of the same thing. It is, theoretically, possible to completely convert a given quantity of matter into energy. The equation tells us how much energy we'd get out. It's a lot. Nuclear bombs convert less than 5% of their mass into energy yet twenty kilograms of plutonium can level a city. If we could achieve 100% conversion, there we be no energy crisis – of course, we'd also be able to build truly hellish weapons.
There is a way, however. We could use antimatter. Antimatter is sort of the mirror of ordinary matter. For the purposes of this essay, the important thing about antimatter is what happens when it comes into contact with ordinary matter. The antimatter and the regular matter annihilate with 100% efficiency. Their entire mass is converted into energy. Even better, we can actually create antimatter. Unfortunately, it's expensive and time consuming. Even creating a microgram of antimatter would cost tremendous amounts of money and consume huge amounts of time (we'd also want to be very careful with it so that we didn't accidentally vaporize ourselves in the process).
Let us suppose that these are merely technical hurdles. Suppose that we could generate antimatter in bulk. Is this our ticket to the stars? Yes – sort of. Antimatter, to, falls prey to the diabolic relationship. Even with antimatter, you can only carry so much before you start to hit the limit of diminishing returns. I've seen designs that purport to allow relativistic travel to the nearest stars. The ships described are very small and very light with the majority of the ship being taken up by the reaction mass. They are suitable for carrying only a small crew of astronauts. Even with antimatter, there will be no Star Trek style luxury liners in our future.
Over the years, various brilliant people have tried to find a way around the diabolic equation. One promising idea was known as a Bussard Ram Jet (after the man who conceived it). The idea was that it would be a ship that would scoop up interstellar hydrogen to use as a fuel. Since the ship wouldn't need to carry its reaction mass, it would circumvent the problem. Alas, there's a hitch. The act of scooping up the hydrogen would cause the ship to decelerate. The more you scooped up, the more you'd decelerate.
This is an all too common outcome of interstellar travel proposals. Let us suppose, however, that we can, at least, get past this hurdle. We're still not free and clear. Traveling at relativistic velocities introduces its own set of problems. The biggest problem is that when you're moving near the speed of light (relative to your environment), everything else is moving past you at the same velocity. A grain of interstellar dust might seem a small thing, but when you slam into it at 90% of the speed of light, it's like being hit by a missile packed with high explosives. Even the smallest particles pose a problem because they would zip through your body with all the energy of cosmic rays. It would be like being continually exposed to hard radiation.
The sad fact of the matter is that we don't live in a convenient universe. The very nearest stars are terribly far away. If we do eventually go out to the stars, we'll be going very slowly. Still fast enough to make the Fermi Paradox an issue but not fast enough to fulfill our dreams of imminent alien contact.
Very well, slow but steady wins the race, right? It depends. If there is intelligent life in our galaxy, our distant descendants may one day encounter it. What if, however, life isn't quite that common? After all, since we know that a galaxy can be colonized in a relatively brief span, this may well indicate that if you are an intelligent species in a galaxy, you are almost certainly the first such species. If you weren't, you would never have had a chance to develop in the first place since your world would have long since been colonized or utilized by whichever species did come first. Consider it a special case of the Weak Anthropic Principle.
So what? First in our galaxy doesn't mean first in every galaxy. Traveling between galaxies is even more daunting than traveling between stars but we may suppose that we could find some way to manage (perhaps with ultra-advanced hibernation technologies). Maybe it would take millions or even billions of years to find our neighbors but, in the end, we would not be alone.
Unfortunately, there appears to be a time limit to such explorations and the clock is already ticking.
This concludes part three of this essay. Part four will be published next Sunday.
Saturday, July 24, 2004
I would like to announce the creation of a sister site to Unstructured Musings called Unstructured Poems.
Readers of this site may have noticed that, each Thursday, for the last several months, I've been publishing poetry under the title Thursday Poetry Slam. I will continue to do so, however, Unstructured Poems will serve as a dedicated repository for the poems that I post here.
In addition to the poems, themselves, I have also added commentaries beneath each of them to discuss the thoughts and techniques that went into their individual creations as well as my personal impressions of them.
You may also notice that I have also added a permanent link to the new site on my sidebar (over to the right). I hope you'll stop on over and take a peek.
Thursday, July 22, 2004
I ran into the Aesir,
Down at the grocery store.
They were in the liquor section
Looking for a case of mead.
(They eventually settled on
Some generic factory beer)
I asked them how they were.
Odin shrugged and said
That he'd just sold his Ravens
To a high bidder, online.
Thor said that he was
Working in construction
Where there's always a place
For those who can handle
Loki, as usual, was elusive
But I got the feeling
That he was looking for something
Out in Hollywood.
It's a good place
For tricksters and myths.
I told them that it had been too long,
That they should call me,
That we should get together
We all knew that we wouldn't.
I said my goodbyes
As they wandered on over
To the meat and dairy section
Looking for some fresh goat flesh.
Monday, July 19, 2004
I will confess that I've never much desired to have a tattoo. For me it isn't a matter of squemishness or thinking that tattoos look "gross" or anything like that. Rather, I've always worried that I've never been able to come up with anything that I'm sure I'd still want to have in another ten or fifty years.
Be that as it may, I saw something recently that is making me seriously reconsider the whole idea. Three little words: Black Light Tattoos.
The really nice thing about them is that you can get them so that they are only visible under a UV light so that, even if you get stuck with something that you ultimately don't like, it's not that big of a deal.
It should be noted, however, that many dermatologists, as well as various tattoo artists, have expressed concerns regarding the inks that are used, stating that some people could have allergic reactions from them.
As always, caveat emptor.
For many years I've used and admired the Logic and Fallacies list on The Atheism Web. It is my considered opinion that it's one of the best lists of such fallacies on the entire web and that it should be required reading for anyone interested in engaging in rational debate and discussion.
I have recently had the rare honor of having an entry of my own added to the list. Readers of Unstructured Musings may recall that I wrote an essay arguing for the existence of a fallacy that I called The Fallacy of Mediocrity. I am thrilled to report that the owner of the Atheism Web has agreed that this is a fallacy that merits inclusion on the Logic and Fallacies list. It's listed as a sub-type under Fallacies of Composition and includes the description and one of the examples that I provided in my original essay (as well as a link to my essay).
In the grand scheme of things, this is not a historical accomplishment. Never the less, for me, this is a prideful moment. You'll pardon me, I hope, if I pat myself on the back for just a little bit.
Sunday, July 18, 2004
This is part two of a four part essay. In this section I will discuss the question of whether or not we can expect to find intelligence anywhere in the universe.
Before I begin this section of this essay, I'm going to need to take a bit of a detour in order to introduce the concepts of Vast and Vanishing.
We use these terms to represent sets that are utterly immense and fractions of those sets that are utterly small. A typical example of a Vast set is the set of all possible books that are of a given length. Let us call this set of books the Library of Babel. The number of the books is not infinite but it is intensely huge. If we limit the set to books with five hundred pages (meaning about 1,000,000 characters per book, including spaces), we get a figure of about 10 to the power of 10 million books. For those unfamiliar with scientific notation, that's a one followed by ten million zeros. Given that each zero magnifies the number by a factor of 10, that's a truly Vast quantity. For the sake of comparison, it is estimated that there are approximately 10 to the 80th particles in the visible universe (give or take a few orders of magnitude). There isn't even enough matter in the universe to merely compile an index of the Library of Babel.
Most of the books in the Library are going to be gibberish: essentially random strings of characters, numerals and spaces. Here and there you will find a word or (much more rarely) even a complete sentence buried within the pages of a selected book. Every book that has ever been written as well as every book that could be written are somewhere in the Library, but unless you had a very, very powerful indexing system (or an omniscient Librarian), it would be unlikely that you could find them.
Let us suppose, however, that we could manage to sneak in and steal copies of all of the books that have ever been written. For the sake of argument, let's be generous and suppose that 10 billion (or 10 thousand million, if you prefer) books have been written over the course of history. That quantity would represent a mere 1 over 10 to the 999,990th of the books in the library. This would constitute a Vanishing quantity. Assuming that the books were shelved at random, even a googol of years (that's 10 to the 100th power) would not suffice to find a single gap in the library in spite of our pilfering.
One final thought and then I'll see about getting back on track. Something can simultaneously be Vast and Vanishing. As noted, the Library contains not only every book that has been written, but every book that could ever be written. If we could somehow separate out just the books that had coherent narratives, we would have a Vast quantity of books. However, in spite of the Vastness of this collection, when compared to the Vast set of books that just contain gibberish and random snippets of words and sentences, the set would have to be considered Vanishing. We will use the compound term "Vast but Vanishing" to describe sets that are inconceivably large while, simultaneously, being an inconceivably small fraction of an even Vaster set.
So what does this have to do with cosmology? The answer is that it has to do with Inflationary Theory. Inflationary Theory is actually a collection of theories pertaining to the origin of the universe. Specifically, Inflationary Models are addendums to classic Big Bang models of the universe. The idea that the universe expanded out of a point-like origin (the Bang) has been well supported by empirical data. Unfortunately, there's a number of technical problems with the simplest models (which I won't be going into in this essay – we hardly need even more detours). Inflationary Models address these problems by proposing that the universe went through a brief but important period of inflationary expansion where space-time went through a sequence of exponential doublings (space-time isn't an object and is, therefore, not constrained by speed of light limitations). Inflation has gained wide favor among cosmologists because it not only solves the standard problems that confront classical Big Bang models but because they are extremely good at accounting for all of the observational data that we've accumulated. The COBE microwave background survey is widely viewed as a compelling vindication of Inflationary cosmology.
And what does that have to do with anything? Patience, we are almost there. The visible universe has a radius of about 10 billion light years (give or take a few billion light years). That's a large enough figure but the visible universe is only a portion of the whole universe. We can't see any further because the light from more distant portions of the universe hasn't had time to reach us, yet. In principle, if we could wait another 10 billion years, the radius of the visible universe would be 20 billion years (or not, but more on that next week).
So, how big is the universe? Inflation suggests that it's not only larger but Vastly larger. I've seen estimates that place the size of the universe at 10 to the 2,000,000th power or even larger (some suggest that it's infinitely large). You might well ask 10 to the 2,000,000th power of what. Do I mean light years, centimeters, furlongs or smoots? The answer is that at that scale, it doesn't matter. Whether you are talking microns or mega-parsecs, the difference is going to get smeared out by the margin of error. It will suffice to say that the real universe may, in fact, be Vast.
So let us agree that life is rare. Let us, in fact, suppose that it is Vanishingly rare. For the sake of argument, I will propose a value of one planet harboring life for any given radius of a googol light years. I will further postulate that of the worlds that have life, only one in a trillion, trillion (10 to the 24th power) would harbor intelligence. I think that there is no question that this is a Vanishingly low density of life. It would, never the less, be Vast number (I'll leave it to the mathematically inclined to work out how Vast). Even something that is Vanishingly unlikely can become inevitable against a large enough span.
As an aside, the physicist Max Tegmark actually used a similar idea as basis for arguing that not only ought there be other life in the universe but that, if the universe were infinite (or, at least, sufficiently Vast), there should be a perfect duplicate of you out there. By his estimates, your nearest doppleganger is about 10100,000,000,000,000 light years away from us.
Is this, then, a vindication of the Principle? Only to a degree. When we dream of alien intelligences our dreams aren't limited to the simple hope that they exist. We dream of someday meeting them. In this, the universe may well disappoint us.
This concludes part two of this essay. Part three will be published next Sunday.
I would like to acknowledge the philosopher Daniel Dennett for the concepts of Vast and Vanishing.
Wednesday, July 14, 2004
I remember the future.
When I was born
It was the size of worlds.
Every time I closed my eyes
I could see galactic whirls
Filled with potentiality.
By the time I was ten,
The future had shrunk
To something merely planetary
In scope and scale.
I could point to some far place
And say that someday,
If I started walking right now,
I could be there before I died.
By the time I was twenty-one
The future had suffered
An environmental catastrophe.
Some Velikovskian god had taken
Whole continents of possibility
And tossed them into the void-dream,
Perhaps to be found by another,
But forever lost to me.
Now the future
Is barely larger than the present;
Where I once wandered
A labyrinth of possibilities,
There are now only
A few dozen paths,
Most of which are pointing
In the same general direction.
One day the future and I
Will collapse to a point.
In the absence of uncertainty
There will only be
The thin line of history
Leading to a singularity.
Recently Blogger announced the creation of a new service called Audioblogger which allows you to phone in messages that would be instantly posted to your blog as a sound file which is identified with a tag that looks like this:
I'll confess that, at first, I didn't see that there would be much with in this service to me. After some reflection, however, I thought that it might be kind of cool to phone it readings of the poems that I post each Thursday. Although I sincerely believe that a poem must stand or fall on its text, alone, I think that a reading can offer certain levels of nuance that aren't available to plain text.
I've gone back and retroactively added audio links of my readings to all of the poems that I've already published. I will also do so on all future poems. All I ask is that you bear in mind that these were, literally, called in over a phone so the sound won't exactly be studio quality (to say nothing of the fact that I'm no James Earl Jones).
|The Midnight Maid||Hey Diddle Diddle||The New Thing|
|A Timid Madness||The Wind as a Mistress to the Seasons||That Feeling|
|Leavetaking||A Cold Cryptography||The Sacrifice|
Tuesday, July 13, 2004
Anyone who has ever seen Monty Python and the Holy Grail has probably wondered what the airspeed velocity of an unladed swallow actually is.
Fortunately, the world is full of people with too much time. Today's link is to http://www.style.org/unladenswallow/ which gives an almost too thorough examination of the subject.
Monday, July 12, 2004
Two children were discussing how lightbulbs worked. One child claimed that they worked because every lightbulb had a magical lightbulb fairy in it. When you flicked on the light switch, it would send a signal to the fairy to make the lightbulb glow.
The second child said that was ridiculous and that he didn't believe in lightbulb fairies.
The first child scoffed at this and replied that if there were no lightbulb fairies then what made lightbulbs glow?
The second child admitted that he didn't have any idea how lightbulbs worked.
The first child smiled and said, "See? I'm right. It's a lightbulb fairy!"
The moral of this story is that, when you don't know the answer to a question, an honest admission of ignorance is better than a false claim of knowledge.
Sunday, July 11, 2004
This is part one of a four part essay. In this section, I will introduce the concept of the Copernican Principle (aka, the Principle of Mediocrity) as well as recent challenges to it in the form of the Rare Earth Hypothesis.
Once upon a time, not all that very long ago, many people sincerely believed in fairies (sometimes called elves, leprechauns or what not). It was believed that fairies lived an otherworldly realm that would only occasionally intersect with the human one. They were believed to have great powers and intelligence. It was thought that would occasionally take people into their realm for purposes that were sometimes benevolent, sometimes malevolent and often incomprehensible.
In cultural terms, aliens have come to occupy much of the mythological space that fairies once inhabited. Popular culture sees aliens as mysterious, intelligent beings (sometimes good, sometimes evil, often incomprehensible) that intersect our world at will, appear when and where they want to whom they want and, all to often, taking hapless souls into their ships for the purposes of study and experimentation.
I, for one, think that popular accounts of aliens are just that – modern day fairy tales. Be that as it may, I am hardly alone in sometimes looking up at the sky and wondering whether or not someone else, up there, is looking outwards too. The very idea of alien cultures and civilizations is invigorating. I grew up on the science fiction perspective that aliens were inevitable and that it was only a matter of time before we would come into contact with them (for good or ill). The Roddenberryesque notion that, one day, we would become explorers finding new worlds with new peoples on a weekly basis was thrilling and invigorating.
But are they, in fact, there? When we look up at the sky are we seeing civilizations without end or are we, merely, seeing nothing but bright embers and dust?
A little over five hundred years ago, Nicolas Copernicus fired the first salvo that would displace us from the center of the universe with the publication of De Revolutionibus Orbium Caelestium (On the Revolution of the Celestial Orbs). Up until that point in time, the dominant cosmological model was the Ptolemaic model which positioned the Earth at the center of the universe. Contrary to certain popularizations of this, Copernicus' contention was not met with immediate outrage and censure. The general reaction, even among scholars, was to simply ignore it.
It wasn't until Galileo's observations of the moons of Jupiter (which demonstrated the existence of a sort of miniature solar system) did the issue become heated. Everyone is familiar with Galileo's trial and the fact that he was forced to publicly recant the Copernican view. By that point, however, the Ptolemaic theory was already a lost cause.
Over the intervening centuries it became clear that the Earth wasn't only not at the center of the solar system but that the solar system, itself, was not at the center of the universe. In fact, our sun turned out to be a rather ordinary seeming start in a rather ordinary position in a rather ordinary galaxy that was, in turn, one of hundreds of billions of galaxies that were visible to us.
If I may be allowed a very brief tangent, science and philosophy have a special relationship. Too often they are viewed as alternatives to one another but the truth is that science and philosophy are deeply intertwined. In point of fact, science was originally known as Natural Philosophy (to distinguish it from metaphysical philosophy). Over time, science has become its own field and many scientists have come to see philosophy as nothing more than a distraction (a compliment that many philosophers are all too happy to return) but the fact is that philosophical questions impinge on science (bioethics, to give an easy example) and scientific questions impinge upon philosophy.
As our place in the universe got knocked from one peg down to the next, a new philosophical principle started to take hold. It's known as either the Copernican Principle or the Principle of Mediocrity.
The Principle of Mediocrity states that we should assume that any aspect of our local environment (including the existence of life and intelligence) should be assumed to be a common aspect of the universe as a whole (in more formal terms, it is the proposition that there are no privileged observers in the universe, but let's stick with the lay formulation, for now). It should be stressed that the Principle is assumed to have a certain "resolution" or granularity. We would not expect, for instance, to find that Starbucks coffee shops are common in the universe (no matter how tempting the thought) nor would be expect to find human beings out there. We should, however, expect to find life and intelligence (perhaps even humanoid life, but that's a much more controversial proposition). When we gaze up at the stars so, too, should others be gazing out from them at us.
Most science fiction stories implicitly accept that the Principle holds (at least with respect to the existence of intelligent life). Astrobiologists have also tended to favor a Copernican interpretation. Until very recently, there was little reason to suppose that the Principle wouldn't continue to hold with respect to the question of life and intelligence. Recently, however, there have been counter-salvoes that have challenged this assumption.
In the last decade, we have finally found conclusive evidence for the existence of extra-solar planets. In fact, we've found dozens of worlds just in the local neighborhood. At first glance, this should seem like a vindication of the Principle. There's one problem: the solar systems that we've discovered don't tend to bear much resemblance to our own.
The most obvious difference is that the worlds we are finding have tended to fall into the "super-Jovian" classification of planets. A super-Jovian planet is one that has more mass (typically a lot more mass) than the mass of Jupiter which is, of course, the most massive planet in our own solar system. It must be understood that the primary reason for this is that our methods of detection only allow us to find massive worlds. It is as though we conducted a census that only included people who weighed more than 300 pounds (about 135 kilograms). Naturally such a census would imply that everyone in the world was obese.
There's a problem with this observation, however. There are too many super-Jovians. If we sent out our selective census taker, we'd expect him to report that most houses were apparently empty (because most houses wouldn't have 300 pound residents). If, however, he came back and reported that nearly every house had at least one 300+ pound resident then we would have good cause to suspect that a disturbing number of people were, in fact, quite heavy. That's what we've been finding with our planetary census. Almost everyone we've been looking, we've been finding planets – extremely massive planets.
This, in itself, might only suggest that our solar system is merely unusual in lacking a super-Jovian or two but there's more. Solar systems aren't like the clockwork orrerys that we learned about in school. Solar systems are dynamic systems. Over time, planetary orbits can (and do) change. In our own solar system, the orbits of the planets have been remarkably stable over the last four and a half billion years, or so. Likewise, the orbits of our worlds are almost perfectly circular (the elliptical deviation of the Earth, for instance, is so slight that it would be invisible to the naked eye if it were rendered to scale). When we look at other solar systems, however, we tend to find things aren't at all like they are in our solar system.
A disturbing number of the super-Jovians we are discovering fall into two categories. The first category of planets are what are known as "hot Jupiters". These are massive planets with extremely close orbits to their stars. Most of these worlds make complete orbits of their parent stars in a matter of days. Many others fall into a category that is prosaically called "eccentrics". An eccentric planet is one that has an extremely pronounced elliptical orbit. The more eccentric a planet's orbit, the more likely it would be to cross the orbits of other worlds.
Worlds do collide. It is believed that our own world was impacted by another world the size of Mars about four and a half billion years ago (leading to the formation of our anomalous moon). Planetary collisions, however, are expected to come to end relatively early in a solar systems history for the simple reason that any bodies that are in collision producing orbits would, in fact, collide within a few tens of millions of years. Collisions, however, are relatively rare events even in a young solar system. A bigger concern is gravitational interactions.
Massive planets have, naturally enough, massive gravitational fields. When a big planet passes near a smaller world, even if they don't collide, they will experience gravitational interaction. Like an uneven game of tug of war between an adult and a child, the smaller world will bear the brunt of this, being yanked well out of its existing orbit. It is entirely possible for a world to be either tossed into its star or to be ejected from its solar system entirely. Eccentric Jovians and super-Jovians would tend to have this effect on any terrestrial worlds (smaller, rocky worlds like the earth). Hot Jupiters are thought to be the end result of such ejection events as the super-Jovians eventually end up in hyper-close orbits around their parents.
The fact that we're finding so many solar systems like this is a blow to the notion that our solar system is pretty much like any other one. It would seem that we are, in fact, somewhat special (and not merely in the naïve "Goldilocks" proposition that our solar system is "just right" for us -- much as an intelligent puddle might observe that the hole that contains it is perfectly contoured to it). If Hot Jupiters and Eccentrics are, in fact, the norm it would follow that our own solar system is, literally, abnormal. In other words, we get to move up a peg on the Copernican scale. There is, after all, something that is privileged about our place in the universe (at least relatively speaking).
Just how many pegs up do we get to go, though? Two scientists by the name of Peter Ward and Don Brownlee have recently published a book called Rare Earth which advances the proposition that complex life is, in fact, very rare (they would contend that it may even be unique although I'm going to dispute that further on). In addition to the extra-solar planetary surveys that I've already discussed, they add additional arguments that include speculations regarding the moon's role in the advancement of life, the role of having "good" Jovians in proper orbits to sweep up asteroids and comets, the critical role of plate tectonics, and so forth. Their ultimate conclusion is that there are additional factors that must be added to the famous Drake Equation and that, when those factors are accounted for, the expected conclusion is that worlds with complex life should be exceedingly rare.
The Rare Earth hypothesis is not without controversy and not without its detractors. A number of their proposed factors rely of either preliminary or speculative data and it is not entirely clear what values should be plugged into each of their proposed factors. Be that as it may, there is one observation that seems to make Rare Earth much more credible: the Great Silence.
As I've noted in my previous essay on the Fermi Paradox, one of the most puzzling aspects of the search for extra-terrestrial life is that we haven't already found it. If intelligent life were to arise within a galaxy, it should be able to colonize every available world in the galaxy within an astronomically insignificant interval. Not only should the galaxy be screaming with communications between colonies but extra-terrestrials should be here and have already been here for hundreds (if not billions) of years. The profound silence of the universe and the utter lack of credible evidence for extraterrestrial visitation is a puzzle that demands consideration. Of all the proposed solutions to the Fermi Paradox, the very simplest is that there isn't anyone out there. The Rare Earth hypothesis provides a theoretical and (partially) empirical framework that supports this conclusion.
Is this, then, the doom of the Principle of Mediocrity? Not quite. As noted, the Rare Earth Hypothesis is not universally embraced. Even with the damning evidence that our solar system might not be common, we don't know how uncommon terrestrial worlds are. There are projects in the works that should allow us to resolve Earth-sized worlds by the end of the decade. We may even be able to determine what sort of atmospheres such worlds would have. If we find the presence of free oxygen, we would have strong cause to conclude that extraterrestrial life of some type does exist (although it may be as simple as bacterial life) since atmospheric oxygen, without the replenishing effects of life, is chemically reactive and would be absorbed into the crust of a planet within a few million years, otherwise.
Even so, finding evidence of life is not the same as finding evidence of intelligence or, even, evidence of complex life. We must face the very real possibility that the Rare Earth Hypothesis is an accurate rebuttal to the Copernican Hypothesis. Intelligence may be rare. The question then becomes how rare.
Curiously enough, cosmology gives us a reason to suppose that no matter how rare it is, we should expect that there are an immense number of intelligences in existence.
This concludes part one of this essay. Part two will be published next Sunday.
Saturday, July 10, 2004
I'm not in the habit of randomly endorsing products but, every so often, I come across something that actually lives up to its own hype. One such product is the Mr. Clean Magic Eraser (or the much more classy sounding Effaceur Magique if you prefer French).
Basically it's like a sponge with some sort of dry chemical in it that's activated by water and which will, doubtless, one day be determined to cause deep chromosomal mutations. As it advertises, it's exceedingly effective at getting deep grime out of a wide variety of surfaces. I'm not exactly the paragon of cleanliness and, consequently, there's a lot of set-in shmutz around the house. This is a great product for domestically lax people such as myself.
The site offers a free sample. If you have no especial qualms about getting on a mailing list, I'd recommend checking it out (or plopping down a few bucks at your grocery store).
Thursday, July 08, 2004
A bloated thing
Blistered and blundering
To its sacrifice
Long hairs wicking
The scent of kerosene
Through wide nostrils
Of long knives
Carve the air
Fallen to its knees
Waiting for the blade
Neck raised high
Fires Burning as
The priests exchange
Blood for rain
Tuesday, July 06, 2004
If anyone has ever sent you a monsterously long URL that wraps across several lines of email, you know what a pain in the patookus it is to reassemble. Of course, you inflict this same inconvenience on others when you do the same.
Now there's TinyURL, which is a site that will take huge URLs, such as http://andrewlias.blogspot.com/2004/04/how-to-tell-your-ass-from-hole-in.html, and, intuitively enough, create small and manageable URLs, such as http://tinyurl.com/3b726, that act as redirects to the real URL.
Sunday, July 04, 2004
In recent years there has been a lot of hoopla as a seemingly endless list of genes "for" various things have been reported. We have heard that there are genes for obesity, genes for depression, genes for reading ability and all sorts of other behavioral traits. One of the more controversial claims has been claims that a gene for homosexuality has been discovered.
Much of the controversy is scientific. It is notoriously difficult to accurately map human behaviors to genetic components and there have been methodological challenges to this claim. This is, ultimately, an empirical question with a great many complicating factors and methodological hurdles. The scientific community has not reached a consensus on this claim and it is unlikely that any consensus will be reached in the near future.
It is not the purpose of this essay to address the scientific question. I will leave that to the experts. Many of the objections, however, are not scientific. One objection, in particular, attempts to make an a priori argument against the very possibility of a so-called "homosexual gene" using a spurious evolutionary argument. The argument can be aptly summarized by the claim that any homosexual gene would have disappeared from the population long ago since homosexuals don't reproduce.
On the face of it, the argument seems convincing. As far as genetics is concerned, there is no difference between dying in your crib and being a childless person who lives to the age of a hundred. So long as you fail to reproduce, your body is a genetic graveyard. Since homosexual sex does not result in offspring, it would seem logical, then, that homosexuality would have been bred out of the populace. I will demonstrate that there are several flaws with this argument.
The first problem is that homosexuality does not preclude the possibility of reproductive activity. In modern times, homosexual individuals can have children by utilizing a variety of technological solutions. Gay men can donate their sperm or find a surrogate mother. Lesbian women have a variety of in vitro and in utero options. Beyond that, there is nothing that physically prevents homosexuals from engaging in heterosexual acts. Indeed, in social climates where homosexuality is criminalized or where there is strong social pressure to conform to heterosexual norms, it is not at all uncommon for homosexuals to conform to heterosexual norms up to and including marriage and parenthood. In such a climate (which has been sadly common throughout history), even if the view of genetics that this argument projects were to obtain, any hypothetical genes for homosexuality would have few barriers to propagation. That said, the a priori argument does employ a naïve understanding of population genetics.
For the basis of this examination, let us consider a hypothesized homosexual gene to be reproductively deleterious (this isn't necessarily the case, but we'll return to that point later). It is critically important to stress that such an evaluation is not a moral judgment but, rather, a neutral statement that only pertains to the reproductive impact that such a hypothesized gene would have. In order to assist our efforts to think of this subject in morally neutral terms, I will not discuss how a gene for homosexuality could propagate itself in a population. I will, instead, discuss a hypothetical S gene that results in sterility. In point of fact, there are a variety of genetic conditions that lead to sterility but, for the purposes of this essay, they can all be subsumed under the common label.
How can a gene which compromises reproduction spread through a population? It would seem that the very first instance of the gene should eliminate itself through an act of genetic suicide. This would only be the case, however, if the presence of a gene invariably resulted in the physical expression of that gene. The technical terms for an organism's genetic structure is its "genotype". The term to describe an organism's physical structure is its "phenotype". Genotype does not equal phenotype. At best, an organism's genotype is an indicator of that organism's phenotype. Simply because I have the S gene, however, does not mean that I will necessarily be sterile.
How can this be? There are several reasons that this could be the case.
The first reason is that there are two different varieties of gene: dominant and recessive. A given gene will occupy a particular location on a chromosome called an allele. In humans (and most other organisms) each allele is occupied by a pair of genes with each half of the pair being inherited for each parent. A given gene will always have a phenotypic expression (meaning that it will be physically manifested) if it is dominant. A recessive gene, on the other hand, will only manifest if it is present in both slots of the allele.
To take a classic example, we'll use a gene for Brown eyes (designated with a capital B) and blue eyes (designated by a lower case b). Let us say that you have double-dominant set of genes for brown eyes (BB) and your partner has the double-recessive genes for blue eyes (bb). Let us further suppose that you have four children. Statistically, your children will receive the following gene combinations: Bb, Bb, bB, bB. Because brown is dominant, all four children will have brown eyes; however, each of them will carry a gene for blue eyes.
Let us suppose, now, that one of your children (Bb) marries a person who also have a dominant brown gene and a recessive blue gene (Bb). Statistically, your children will receive this combination: BB, Bb, bB, bb. Only the child with the bb gene combination will have blue eyes (although an additional two children will continue to carry the recessive genes for blue eyes.
If sterility were to be carried on a recessive gene, it could persist in the gene pool indefinitely in spite of the fact that it conferred a reproductive disadvantage. It is important to stress that, even though it would be allowed to persist, there would a critical population threshold above which an anti-reproductive gene would be selected against. Scandinavians are famed for having blue eyes. This is because their population has an abundance of the recessive genes that confer blue eyes. Since there is no reproductive disadvantage, such a bias in population is allowed. You would not, however, expect to find an equivalent population where an S gene had a majority representation in the populace.
There is, however, one way that an S recessive could positively leverage itself into future generations. This is via the mechanism of kin selection. The easiest way for a gene to get into the next generation is directly. This is why the sex instinct is so strong. When we have children, each child carries 50% of our genes into the next generation. So what happens if we can't have children? The solution is that we turn to our relatives. If you have brothers and sisters, each of them also has a 50% genetic relation to you. Any nephews or nieces you have will have a 25% relation. This isn't as high as your own children would be but, if you can't have children of your own, any additional assistance you could provide to your siblings to help them raise your nephews and nieces will be to your genetic advantage.
The elegant thing about this supposition is that we don't have to even suppose that the S gene would directly encourage you to devote your efforts to your sibling's children. So long as you have a general instinct to expend more effort on your closest relatives when you, yourself, are reproductively disadvantaged, such an instinct would be positively selected for. After all, genes aren't the only reasons one may be unable to reproduce. Circumstances alone (e.g., accidental castration) guarantees that a certain percentage of any given generation will be unable to reproduce regardless of genetics. As such, a kin assistance instinct would represent a good genetic strategy regardless. If humans do have such an instinct (and it must be stressed that this is speculative), any sort of recessive S gene would automatically result in efforts to assist non-manifesting copies of itself in near relatives even if the S gene were entirely deleterious for the individual who was carrying it.
Beyond this, the simple "pea pod" Mendelian model, where a single set of genes accounts for all of the genetic variance in a population, is, itself, typically an oversimplification. There is not, for instance, a single tall gene and a single short gene that determines whether one is short or tall. In reality, height is determined by a complex of different genes interacting in tandem (along with a variety of environmental factors, but let's not get ahead of ourselves). This is how things work in most cases of phenotypic expression. Instead of P = G (for every phenotype there is one and only one gene), P = G1, G2, G3… (for every phenotype there are multiple genes). Because of this, it is possible for certain combination of genes to result in anti-reproductive outcomes (e.g., sterility or premature death) while other gene combination are either neutral or reproductively advantagous.
Let us suppose, for the sake of argument, that sterility expresses itself only when four particular genes manifest. Let us further suppose that these four genes have reproductively beneficial manifestations when teamed up with most other alternative sets of genes. In such a schema, not only could these genes persist in spite of the occasional drawback of producing a non-reproducing individual but they could, in fact, be positively selected for because the majority of the time they would give a reproductive advantage to the person that they would find themselves in.
This is a bit like playing an odd game of poker where four aces result in a busted hand. Two aces or three aces would still make for a good hand (as would aces and kings or the aces in a full house, a straight or a flush). Even though four aces would be a "bad" hand, any other combination would be desirable and advantageous.
Beyond this, the path from gene to phenotype is not inevitable. The way that genes "build" bodies is through the production of proteins (with the help of RNA). Every gene encodes in the instructions for building a particular protein. Between the production of proteins and the production of bodies, there are a number of critical steps. During fetal development, various chemical cascades are turned on or off or modified according to the activation and deactivation of various chromosomes. This is a complex process that can often be very fuzzy. This is the reason that geneticists rarely say that gene X determines phenotype Y. Rather, they may say that particular genes result in a predilection for the presence of certain phenotypes. The predilection may be strong or weak but it is rarely absolute.
Take sex as an example. Most of us have been taught that boys have a Y chromosome and that girls don't. In the vast majority of cases, this is true. It is not, however, inevitable. Even discounting intersexual births (where a child is born with indeterminate genitalia) it is possible for a child with a Y chromosome to be born a female and, likewise, for a child who has two X chromosomes to be born a male. In most children, the Y chromosome signals the activation of testosterone production at a critical junction of fetal development. In some births, the signal either fails to go off (a false negative) or it goes off spuriously (a false positive).
If something as strong as sexual determination can only be considered a strong statistical likelihood, it should not surprise us that something as subtle as a behavioral gene could be present without manifesting itself. Even if the supposed S gene were dominant and even if it always resulted in an absence of reproduction when manifested, it would still be possible for non-sterile individuals to carry it forward into the next generation. If there was only a weak predilection, this would actually be the expected case.
Nor do potential environmental impacts end at the womb. Take left handedness as an example. Handedness is believed to have a strong genetic component. Never the less, for years left handedness was considered to represent a kind of moral failing (hence the word "sinister" which is a Latinate form of the word "left"). Because of this immoral reputation, children who exhibited left handed behavior were often sternly corrected (typically with a ruler) and encouraged to use their right hands. Such efforts did not always produce right handed behavior but the success rate (if we can use the word success in reference to such a practice) was sufficiently high that the practice remained in vogue for many years.
Environmental effects do not have to be coercive, either. Consider a predisposition to obesity. Even though an individual may have such a predisposition, it may not manifest itself unless they are exposed to certain foods or dietary conditions. A person with a predisposition to melanoma may not develop skin cancer unless they are exposed to greater than average amounts of UV radiation. Indeed, some genetic predispositions may only manifest spontaneously and at random. As such, perhaps only 25% of individuals with the S gene would actually become sterile (and, then, perhaps only the ones that have consumed high quantities of beta carotene or been exposed to high levels of environmental arsenic).
As we can see, even though it seems intuitive that a gene which would cause sterility would eliminate itself from the population in short order, the truth is that there are a multitude of avenues whereby it can find its way into further generations. Exchanging our S gene for a homosexual gene (or gene complex), we can see that a priori arguments that propose to establish the impossibility of such a gene are based on a fallacious understanding of both genetics as well as the sociological and medical realities.
As I stated earlier, the question or whether or not such genes exist is an empirical question. As such, the question can only be decided by a judicious application of scientific methodology. Philosophical and ideological objections are irrelevant to the question. Likewise, it must be cautioned that while science may be able to answer the empirical question, it is not capable of addressing the moral and theological questions that surround the issue of homosexuality. The absence of such a gene (or genes) can not logically be used to condemn homosexuality but neither can its existence be used to validate it. To do either would be to engage the Naturalistic Fallacy to the benefit of no one. We should be aware of the facts and realities of nature, of course, but what we do with those facts is a different question altogether.