Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, April 28, 1994 TAG: 9404260101
SECTION: EXTRA PAGE: 1 EDITION: METRO
SOURCE: Joel Achenbach
DATELINE: LENGTH: Long
A: Roses are red - but what do we mean by that? Let's not start tossing around words like "red" without coming up with some definitions! Why does red have that characteristic redness? Is the redness an artifact of the brain, varying from person to person, or does everyone see the very same red?
This is a good topic for a late-night argument because the ludicrous position is in fact the correct one: There's no guarantee that people are "seeing" in their minds the same color when they talk about, say, "red" or "green." The redness in your brain may be what another person would call greenness.
Colors can't be described. We can compare red to blood or fire or roses or whatever we want, but such descriptions are fundamentally circular. If you say red is the color of fresh blood, then you have to ask what the color of fresh blood is (red!).
Scientists have a word for the subjective quality of mental experience, such as the redness of red: Qualia.
"Its very difficult to explain something scientifically when you can't describe what it is," says Francis Crick, the Nobel Laureate now working on brain research.
It's possible that the only way to confirm that we all see the same red would be to do brain scans on different people and see if there's a specific electrical pattern associated with red. The problem is, the brain scans of today are crude. They can't possibly home in on something as specific as registering a color. It's like trying to use a bulldozer to find a needle in a haystack.
Philosophers naturally love to argue about things like qualia. The "reductionist" philosophers say we invent redness, that it's just an artifact of our imagination. That theory might sound daffy but it's hard to dismiss. After all, red is nothing more than light (photons) moving at a specific wavelength. Photons aren't red! Nor is a wavelength red. But somehow when the light hits our eye, and registers in our gray matter, we see red. So where's the red, out there in the universe, or just in our heads?
Our best guess: Red is a real artifact of the universe. It's philosophy that's fake. nn
Q: Why did Lindbergh succeed where others failed?
A: You know the story: Someone named Orteig puts up $25,000 for the first non-stop flight from New York to Paris or vice versa. Big fuss. Daredevil pilots crash, burn, disappear over Atlantic, lots of exciting stuff. Young guy named Charles Lindbergh comes out of nowhere, nails it. Instant massive hero. How'd he do it?
The simple answer is, he presumed success. He didn't load his plane with precautions. There was, most noticeably, no co-pilot to spell him if he got tired or sleepy (the Orteig prize didn't require a solo flight). He took no radio, because he knew if he crashed in the Atlantic he'd probably die before anyone found him. He had only one engine rather than the usual two. He didn't pack a life raft. He literally didn't weigh himself down with fear.
So there's today's inspiring trivia nugget: To get far in life, never countenance failure. Though marrying someone rich is also a good technique. nn
Q: Why can you stare at a 2-dimensional graphic called a stereogram and see, after several minutes, a very clear 3-dimensional image?
A: Stereograms are a fad. A kind of slow, no-one's-ever-heard-of-it fad, but a fad nonetheless. A stereogram is a piece of paper with what appears to be a meaningless pattern on it, but if you stare at the pattern and intentionally blur your vision, as though you were trying to focus on something behind the piece of paper, you will eventually experience something startling: A 3-D image will lift off the page.
It takes a while. Your eyes may hurt. But when it happens, the image is vividly 3-D, like a hologram.
We called Dan Dyckman, a computer programmer who created the stereogram, and he explained that these things are based on the fundamental principles of stereo vision, to wit:
Our two eyes give us two separate images of the world, and the brain combines them into a single 3-D image. The brain does this by registering parallax shifts. That sounds complicated but can be easily demonstrated: Hold your finger a few inches in front of your face and look at it with alternate eyes, left and right. The finger jumps, or shifts, back and forth. A finger held further away doesn't shift so much. The brain knows that objects that shift a lot are close, and ones that don't shift much are far away.
A stereogram is computer-generated in such a way as to fool the brain:
"If you look closely at one of these `hidden-dimension' images, you'll notice that they're kind of built out of columns, with vertical strips running up and down the image, with each strip almost identical to its neighbor, but slightly different," says Dyckman.
"When you view one of these images properly, your left eye will be looking at one of the columns and your right eye will be looking at the immediately adjacent column to the right, but your mind will be thinking that you're looking at a regular scene, and your mind will pick up the very slight difference between those two columns and it will interpret them as parallax shifts."
So your brain says, wait, this isn't a 2-D scene, this is 3-D, and it yanks a piece of the image off the flat surface of the paper and projects it as being closer to you.
Neat! Now let's just hope we won't be cross-eyed for life.
Washington Post Writers Group
by CNB