January 21st, 1999
During one of the pioneering spacewalks back in the 1960s, an astronaut inadvertently lost something; I think it was an outer glove, which went floating off into space. At first there were lots of jokes about the "Lost in Space Glove", but some people weren’t amused. They considered this a form of environmental pollution. After all, here we were visiting space for the first time in history and the first thing we do is litter the place. It certainly got some peoples’ hackles up. Later on, the Jefferson Airplane wrote a song with a reference to the incident: "American garbage left in space and no room left for brotherhood”.
I was struck by this line, because it represents such a ridiculous fallacy that is nonetheless understandable. The error here is a failure to appreciate the vastness of space. Referring to the lost glove as litter is ludicrous given how empty space is. For example, suppose that by some miracle of science, we developed a process that transforms anything -- dirt, rocks, trees, water, air, anything -- into cellophane wrappers for Twinkies. Presumably these wrappers would bear the legend "New! Improved!" Now, suppose further that, owing to some minor computer error, we proceeded to transform the entire planet of Earth into cellophane wrappers. Suppose that somehow these cellophane wrappers then became evenly distributed across the solar system. It would be utterly beyond the reach of current technology for a scientist based on Mars to detect any evidence of those cellophane wrappers. That’s how big space is -- and how small our planet is.
At bottom, the mental failure here is a failure of imagination, an insistence on applying common sense rules of thumb to intellectual contexts where they no longer apply. It’s not as if the critical information is hidden away in some secret science book; any school child can, or should be able to, tell you that the earth is 93 million miles away from the sun. The problem is, people refuse to confront a number like "93 million miles" with any intellectual honesty. The sun is near the earth the same way the gas station is near my house. I wouldn’t drop litter on the way to the gas station, so why should I drop litter out there in space?
We see the same kind of failure at the heart of many other controversies. Evolution offers a prime example. The other day I was explaining hominid evolution during the last 3 million years to a friend. She interrupted me with the question, "I believe in evolution, but could all those changes really have taken place?" I responded with a mental experiment. "Suppose we had two photos, one of me, and one of Fred Homo Erectus from three million years ago. Suppose further that we use a morphing program to morph Fred’s photo into mine. But, suppose that we did this morphing process in 150,000 steps, because there are 150,000 generations between Fred and myself. Do you really think that minute examination of any single adjacent pair of frames in the morphing movie would reveal any noticeable change?" My friend was convinced; she simply hadn’t taken into account the number of generations involved. It was a failure of her imagination to appreciate the vastness of evolutionary time.
Technological design is another area suffering from widespread failure of imagination. The computer, for example, is capable of performing only the most primitive of intellectual operations: addition, subtraction, and so forth. However, it is capable of performing millions of such operations per second. Now, few of us need to have millions of additions carried out, but what if we could take a really serious and interesting problem and somehow re-express it in a form that involved only additions and subtractions? Surely such a reformulation of the problem would be stupendously complicated, but if we could do so, then the computer could in fact solve it for us in a few seconds. Most people fail to imagine the celerity of computation, and so they dismiss the computer as hopelessly stupid, capable of only the most mindless exertions. But with the right programming...
I still clearly recall the moment this concept dawned on me. I had just purchased my first computer, a KIM-1 single-board computer. I fired it up and keyed in the following assembly language program:
This little program might be read as follows: "Load the accumulator with the number 2. Add (with Carry) the number 3. Store the result into memory location 1709". It just so happened the location 1709 was the magic location that was always displayed by the KIM-1. After entering the program, I set the KIM-1 to start the program, and then, with trembling fingers, pressed the "Run" key. In the blink of an eye, it came back with the answer: 5! I was stunned -- and then embarrassed. The computer required only about 10 microseconds to execute that program; did I really think that I would notice the delay? Failure of imagination!
I am not claiming that the human imagination is a wondrous entity, and if only we dismiss our pedestrian constraints, we could unleash the infinite power of the human imagination, blah, blah, blah. My own experiences trying to get my own imagination to solve some difficult problems have convinced me that my imagination seldom rises to the occasion. I think that we should all be happy enough with an imagination that can grasp high-school ideas like evolution, the vastness of space, and what a computer really could do. But most people seem to be running the imagination race with their running shoes unlaced.