SCIENCE FILE / An exploration of issues and trends affecting science, medicine and the environment : A Spectrum of Indefinite Answers
In Trivial Pursuit, a question in the science category asks: How many colors are there in the spectrum?
This is the kind of question that can drive a science buff right up the wall. After all, a spectrum is, well, a spectrum--meaning a continuous range. Anyone who has ever looked at a rainbow knows there is no line demarcating where the red ends and the orange begins. Some cultures even clump blue and green into one color. In ancient Greece, there was no word for green. The word we know as green actually translates as “wet.”
Moreover, the visible spectrum leaks out on each side, bleeding into infrared, microwaves and radio waves on the low end of the spectrum and melting into ultraviolet, X-rays and gamma rays on the high end.
These deliciously blurred boundaries are typical of most areas of science--which may explain why physicists such as UCLA’s Steve Kivelson avoid the science category at all costs when forced into such games.
For example, astronomers recently announced that they had discovered the first “brown dwarf” star. But others insisted that the “star” was a planet. Still other astronomers call the planet Jupiter an almost-star, while some lump puny Pluto with asteroids.
Even the demarcations between states of matter such as solid, liquid and gas are not distinct. Glass, for example, is described as solid liquid. The molecules are strewn about in messy disarray, as in liquids. Yet glass feels solid. Given time, however, heavy glass windows will melt.
Kivelson points out a case he thinks is even more fantastic, in which water vapor under pressure can condense into liquid without going through the usual “phase change” but just appears, like a ghost, as water. Like night turning into day, there’s no clear line.
“You have no question when you’re in night. And no question when you’re in day. But [when] do you get there?”
Science thinks nothing of crossing such boundaries. It routinely comes up with strange hybrids such as “organic metals” and artificial DNA. Biophysics--which might have seemed a contradiction in terms a few dozen years ago--is now one of the most active fields in science.
Chemists, for their part, have a particular problem with distinctions between “natural” and “unnatural.” As Nobel laureate Roald Hoffmann points out, among the human inventions people consider perfectly “natural” are dachshunds and roses--which evolved not by Nature’s hand alone but were brought into being by genetic manipulation.
The truth is, most natural phenomena cannot be crammed into clear categories. Where does the sky end and space begin? Where, exactly, is a coastline? Shifting continental plates and erratic river beds have made a mockery of property lines and national boundaries alike.
Mathematicians know that even numbers can be indeterminate. The ancient Pythagoreans--who developed an entire religion based on the rationality of numbers--murdered a member of their clan who threatened to leak to the world their unsettling accidental discovery that some numbers cannot be expressed as ratios or fractions. That is, you can divide the circumference of a circle by its radius but you cannot write the result as a fraction.
You cannot pin down pi. Like the Energizer Bunny, it just keeps on going. It has no more clear end than a spectrum.
Yet curiously, society often looks to science to draw its lines: to say which fetuses are officially alive, which terminal patients are legally dead; when life and death, like colors, blend into each other; to say who’s black or white, who’s smart or slow, what traits are masculine or feminine.
These days, many scientists would argue that the most interesting things in nature--from life to the evolution of the universe--exist at the blurred boundary between order and chaos. This is the place where things are orderly enough to take form, while not so frozen that things can’t change and that creativity can’t occur.
It is no accident that some scientists now think life originated in tide pools, at the shifting edge between land and sea.
As the science artist Bob Miller of San Francisco likes to point out, there is no graver threat to the process of discovery than that dread disease, “hardening of the categories.”
