If I had never learned about DNA and programming languages, and you asked me to build a machine that can build a copy of itself, I would try to build a general-purpose machine that:
1. Inspects any given machine;
2. Figures out how to build that machine; and
3. Builds the machine.
Then I would set the machine on itself.
But, knowing about DNA and programming languages, I would instead do the following:
1. Design a language that can describe how to build any machine;
2. Build a machine that can understand the language and successfully carry out orders; and
3. Translate instructions for building that machine into the language.
Then I would give the machine the instructions for its own making.
The second strategy is easier than the first because designing languages and translating stuff is something you can do without even getting out of bed; whereas designing a machine that can figure out how to build anything it sees in a systematic way seems impossibly hard. And indeed, the second strategy is basically the one that living things use.
In the past, some people believed that animals contained within their bodies the tiny, undeveloped bodies of all their progeny. It was easier to believe this than to believe that animals are capable of building other animals from scratch. The only problem is that each animal would have to contain a practically infinite number of copies of itself -- one for each of its descendants.
We now know that each animal contains a copy of itself -- not a tiny undeveloped fetus, but in the form of information. When animals appear to make physical copies of themselves, they are really just translating this informational homunculus into a physical being. What's being copied is the information; it's easy to copy information.
Friday, June 27, 2008
Wednesday, April 2, 2008
The genre of fantasy is all about pulling you into an imagined world. There are two fundamentally different ways of doing this.
Chris van Allsburg created the above image for the cover of The Horse and His Boy by C. S. Lewis. It is a window into the land of Calormen, south of magical Narnia; the view invites you to imagine yourself traversing the bridge to the city of Tashbaan, where other wonderful vistas no doubt await.
Now consider the following work of art:
This map accompanies The Book of Ti'Ana by Rand Miller and David Wingrove (among others). It depicts the cavern of D'ni, located miles underground, and a tunnel that leads to the Earth's surface. Notice first that it is two maps: The bird's-eye view of the route spans most of the canvas, from the lake on the left to the volcano on the right. Below it is an elevation view of the same route which runs in parallel to the bird's-eye view. The relationship between the maps is emphasized by the layout: They both curve up and to the right, complementing each other.
The rest of the canvas is taken up by illustrations of small details relevant to the journey. As you trace the path from D'ni to the surface, your attention is drawn to these drawings, and your eye instinctively attempts to read the accompanying captions written in D'ni. But then your attention is drawn to a nearby compass rose line, which you follow back to the map's origin.
This is a piece of fantasy art, but it is also a functional document. It has an interactive quality to it: You can choose to explore the work by tracing a route on the map, or studying the drawings, or scrutinizing the cartographic legends and headings. And all the while, you remain very aware of the fact that you are reading a document.
If you become engrossed in this piece of art, you will not lose the sense of examining a document. And yet a part of you will become convinced that the world depicted really exists, far away underground.
Compare this fantasy with the picture of Tashbaan at the beginning of this article. Becoming engrossed in that artwork makes you forget that you are looking at a picture. You begin to feel that you are really in that other world.
The picture of Tashbaan invites you to enter a fantasy, leaving this world behind. The map of D'ni, on the other hand, allows you to explore a fantasy within the context of this world. These two modes of fantasy are satisfying in different ways.
Chris van Allsburg created the above image for the cover of The Horse and His Boy by C. S. Lewis. It is a window into the land of Calormen, south of magical Narnia; the view invites you to imagine yourself traversing the bridge to the city of Tashbaan, where other wonderful vistas no doubt await.
Now consider the following work of art:
This map accompanies The Book of Ti'Ana by Rand Miller and David Wingrove (among others). It depicts the cavern of D'ni, located miles underground, and a tunnel that leads to the Earth's surface. Notice first that it is two maps: The bird's-eye view of the route spans most of the canvas, from the lake on the left to the volcano on the right. Below it is an elevation view of the same route which runs in parallel to the bird's-eye view. The relationship between the maps is emphasized by the layout: They both curve up and to the right, complementing each other.
The rest of the canvas is taken up by illustrations of small details relevant to the journey. As you trace the path from D'ni to the surface, your attention is drawn to these drawings, and your eye instinctively attempts to read the accompanying captions written in D'ni. But then your attention is drawn to a nearby compass rose line, which you follow back to the map's origin.
This is a piece of fantasy art, but it is also a functional document. It has an interactive quality to it: You can choose to explore the work by tracing a route on the map, or studying the drawings, or scrutinizing the cartographic legends and headings. And all the while, you remain very aware of the fact that you are reading a document.
If you become engrossed in this piece of art, you will not lose the sense of examining a document. And yet a part of you will become convinced that the world depicted really exists, far away underground.
Compare this fantasy with the picture of Tashbaan at the beginning of this article. Becoming engrossed in that artwork makes you forget that you are looking at a picture. You begin to feel that you are really in that other world.
The picture of Tashbaan invites you to enter a fantasy, leaving this world behind. The map of D'ni, on the other hand, allows you to explore a fantasy within the context of this world. These two modes of fantasy are satisfying in different ways.
Saturday, November 24, 2007
Why can't a fish survive out of water?
Why can't a fish survive out of water? There are two different responses to this question:
(1) Because a fish's gills do not work in the air.
(2) Because a fish does not have lungs.
Both of these answer the question, although the former is perhaps the response that comes more naturally to mind.
Determining why something happens is like determining the cause of an event: You imagine a world in which the event does not occur; the imaginary world must also lack the cause. For example, consider the collapse of the Tacoma Narrows Bridge on 7 November 1940. The bridge collapsed because of strong winds on the 7th of November; for without those winds, the bridge would have remained intact that day. The bridge collapsed also because it was negligently designed; for if it had been made stronger, it would have withstood the winds of the 7th of November.
In the case of the fish out of water, I can think of two simple ways of changing the world to save the fish's life, short of throwing it back in the water: The first is to allow its gills to function in the air. The second is to give it lungs. These give rise to solutions (1) and (2) above.
Alternatively, we can determine why a fish on land cannot survive by comparing it with something else that can survive. The crucial difference between the landed fish and a fish in the water is that the landed fish's gills are dry, and so aren't working properly. The crucial difference between the landed fish and ourselves is that the landed fish lacks the lungs we use to breathe.
(1) Because a fish's gills do not work in the air.
(2) Because a fish does not have lungs.
Both of these answer the question, although the former is perhaps the response that comes more naturally to mind.
Determining why something happens is like determining the cause of an event: You imagine a world in which the event does not occur; the imaginary world must also lack the cause. For example, consider the collapse of the Tacoma Narrows Bridge on 7 November 1940. The bridge collapsed because of strong winds on the 7th of November; for without those winds, the bridge would have remained intact that day. The bridge collapsed also because it was negligently designed; for if it had been made stronger, it would have withstood the winds of the 7th of November.
In the case of the fish out of water, I can think of two simple ways of changing the world to save the fish's life, short of throwing it back in the water: The first is to allow its gills to function in the air. The second is to give it lungs. These give rise to solutions (1) and (2) above.
Alternatively, we can determine why a fish on land cannot survive by comparing it with something else that can survive. The crucial difference between the landed fish and a fish in the water is that the landed fish's gills are dry, and so aren't working properly. The crucial difference between the landed fish and ourselves is that the landed fish lacks the lungs we use to breathe.
Sunday, September 23, 2007
Yesterday I read a short story — contemporary, non-genre fiction. I rarely do that, because I usually find such stories to be empty or depressing, or both. But the beginning was interesting, and there were several artful turns of phrase I couldn't help but appreciate. So I kept reading.
(The story is Findings & Impressions by Stellar Kim, not that it matters.)
It starts out like a radiologist's report, but turns into a narrative about a sort of friendship that arises between the narrator and his patient, a woman who is dying of cancer. Okay, so she's a remarkable woman who remains strong in the face of her disease, and the doctor befriends her, and she's going to teach him something about life and death before the end. So far, so good.
Except they never get very close at all (for a number of reasons), and he doesn't learn anything really profound, and the story ends in a very mundane scene. The story reads like the less remarkable parts of my daily life.
I realize that I dislike this story, and stories like it, not because they're about ordinary people or ordinary places, but because they're about ordinary events. I want to read about the extraordinary. I want the cancer patient's approaching death to endow her with some kind of special wisdom or preceptive faculty; I want the two characters to fall madly in love, in defiance of death; I want the doctor to come to terms with the loss of his late wife by realizing with relief that he, too, will die one day.
I find many good stories in science fiction and fantasy, because in the imaginary realms, extraordinary things happen all the time. But it's also okay for realistic fiction to be about extraordinary events. Because in reality, extraordinary things do happen.
(The story is Findings & Impressions by Stellar Kim, not that it matters.)
It starts out like a radiologist's report, but turns into a narrative about a sort of friendship that arises between the narrator and his patient, a woman who is dying of cancer. Okay, so she's a remarkable woman who remains strong in the face of her disease, and the doctor befriends her, and she's going to teach him something about life and death before the end. So far, so good.
Except they never get very close at all (for a number of reasons), and he doesn't learn anything really profound, and the story ends in a very mundane scene. The story reads like the less remarkable parts of my daily life.
I realize that I dislike this story, and stories like it, not because they're about ordinary people or ordinary places, but because they're about ordinary events. I want to read about the extraordinary. I want the cancer patient's approaching death to endow her with some kind of special wisdom or preceptive faculty; I want the two characters to fall madly in love, in defiance of death; I want the doctor to come to terms with the loss of his late wife by realizing with relief that he, too, will die one day.
I find many good stories in science fiction and fantasy, because in the imaginary realms, extraordinary things happen all the time. But it's also okay for realistic fiction to be about extraordinary events. Because in reality, extraordinary things do happen.
Monday, September 10, 2007
A leaf
It's not yet autumn, but I found this prematurely-fallen maple leaf today. The obverse:
The reverse:
Friday, September 7, 2007
Sickness of the mind
I thought I had found a solution, but my sickness has only gotten worse. I recognize the symptoms. I think I'll have to let it play itself out and see what happens.
ADDENDUM: I talked to someone about it, and it turns out that's exactly what I needed.
Wednesday, July 25, 2007
Giant squid
The next time you're laughing with a friend, or walking home, or using the lavatory at night, startle yourself with this realization: There are giant squid. Right now. They are many times the size of your body, and they swim through billions of gallons of ice-cold, pitch-black seawater. Maybe they're hunting food. Maybe they're mating. Maybe they're trying to sleep. You may never see one before you die, but they are alive and living as you go about your life under the sun they will never see.
Subscribe to:
Posts (Atom)