Doing Psychology in an AI Context: A Personal Perspective and Introduction to This Volume
Robert R. Hoffman
The reason that this book exists is because trees are hot in winter infrared photography. Over my Christmas holiday in 1979 I visited a close friend, physicist Walter Carnahan of Indiana State University. I know him to be a specialist in optics and particle physics, which is why I was perplexed when I found him pondering a computer graphic display which merely showed a crazy patchwork of colors. The display seemed to have nothing to do with particle physics, so I figured he had a new software toy or something. But no, this was Science.
"This is a thermogram," he said, "taken over Terre Haute, Indiana, from about a thousand feet. In winter. It's part of an energy conservation project."
Well, I knew what a thermogram was, and although the false-color coding scheme was new to me, I tried my hand at interpretation. "Is this green blob a tree?" I asked.
"No, it's a house. Actually, one with pretty good insulation."
"Oh," was the only word I could muster. But pointing to another region I asked, "So is this yellow blob an uninsulated house?"
"No, that's a tree. Trees are about the hottest things around in winter photography."
The color code, displayed off to one side of the image, seemed to be something like a rainbow, with warmer temperatures being coded as white to yellow to red, cooler temperatures as greens, and cold as blue to black. But it wasn't a perfect rainbow. The hottest white appeared slightly pinkish. The yellows were just awful, and interspersed among the darker blues was a sort of olive-gray color.
"There are a number of things called 'interpretation anomalies' in thermography," Walter explained. "If a tall building has lots of windows that leak heat, then looking down on it, all the whites and yellows make it look as if the sides are ballooning out at you." Later at his home, his family and I had a chance to play with a portable infrared camera, one that enabled us to fiddle with the color coding. (I use the word play advisedly. Not only are such cameras expensive, but they have to be primed with liquid nitrogen.) We performed all manner of experiments, but just simply watching a person through the camera was like nothing I'd ever seen before. The closest I can come to describing the dynamic panoply is that it's like looking at a world of ghosts painted in a Peter Max psychedelic of flowing colors. Ghostlike residues of human activity appear everywhere, such as handprints left glowing on doors. Especially odd were the infrared reflections. For example, a candle could be seen reflected, not in a mirror or window, but in an ordinary wall! Infrared affords a very unusual way of looking at the world.
Fortunately, the experimental psychologist in me is not concerned about making a fool of himself by saying something stupid in the presence of a person who knows tensor calculus. So I asked, "In your aerial thermograms, who decided how to code the different temperature ranges in the different colors?"