Chapter 16 -- "My Built-in Doubter" (page 184)

Once I delivered myself of an oration before a small but select audience of non-scientists on the topic of "What Is Science?" speaking seriously and, I hope, intelligently.

Having completed the talk, there came the question period, and, bless my heart, I wasn't disappointed. A charming young lady up front waved a pretty little hand at me and asked, not a serious question on the nature of science, but: "Dr. Asimov, do you believe in flying saucers?"

With a fixed smile on my face, I proceeded to give the answer I have carefully given after every lecture I have delivered. I said, "No, miss, I do not, and I think anyone who does is a crackpot!"¹

And oh, the surprise on her face!

It is taken for granted by everyone, it seems to me, that because I sometimes write science fiction, I believe in flying saucers, in Atlantis, in clairvoyance and levitation, in the prophecies of the Great Pyramid, in astrology, in Fort's theories, and in the suggestion that Bacon wrote Shakespeare.

No one would ever think that someone who writes fantasies for pre-school children really thinks that rabbits can talk, or that a writer of hard-boiled detective stories really thinks a man can down two quarts of whiskey in five minutes, then make love to two girls in the next five, or that a writer for the ladies' magazines really thinks that virtue always triumphs and that the secretary always marries the handsome boss--but a science-fiction writer apparently must believe in flying saucers.

Well, I do not.

To be sure, I wrote a story once about flying saucers in which I explained their existence very logically. I also wrote a story once in which levitation played a part.

If I can buddy up to such notions long enough to write sober, reasonable stories about them, why, then, do I reject them so definitely in real life?

I can explain by way of a story. A good friend of mine once spent quite a long time trying to persuade me of the truth and validity of what I considered a piece of pseudoscience and bad pseudo-science at that. I sat there listening quite stonily, and none of the cited evidence and instances and proofs had the slightest effect on me.

Finally the gentleman said to me, with considerable annoyance, "Damn it, Isaac, the trouble with you is that you have a built-in doubter."

To which the only answer I could see my way to making was a heartfelt, "Thank God."

If a scientist has one piece of temperamental equipment that is essential to his job, it is that of a built-in doubter. Before he does anything else, he must doubt. He must doubt what others tell him and what he reads in reference books, and, most of all, what his own experiments show him and what his own reasoning tells him.

Such doubt must, of course, exist in varying degrees. It is impossible, impractical, and useless to be a maximal doubter at all times. One cannot (and would not want to) check personally every figure or observation given in a handbook or monograph, before one uses it and then proceed to check it and recheck it until one dies. But, if any trouble arises and nothing else seems wrong, one must be prepared to say to one's self, "Well, now, I wonder if the data I got out of the 'Real Guaranteed Authoritative Very Scientific Handbook' might not be a misprint."

To doubt intelligently requires, therefore, a rough appraisal of the authoritativeness of a source. It also requires a rough estimate of the nature of the statement. If you were to tell me that you had a bottle containing one pound of pure titanium oxide, I would say, "Good," and ask to borrow some if I needed it. Nor would I test it. I would accept its purity on your say-so (until further notice, anyway).

If you were to tell me that you had a bottle containing one pound of pure thulium oxide, I would say with considerable astonishment, "You have? Where?" Then if I had use for the stuff, I would want to run some tests on it and even run it through an ion-exchange column before I could bring myself to use it.

And if you told me that you had a bottle containing one pound of pure americium oxide, I would say, "You're crazy," and walk away. I'm sorry, but my time is reasonably valuable, and I do not consider that statement to have enough chance of validity even to warrant my stepping into the next room to look at the bottle.

What I am trying to say is that doubting is far more important to the advance of science than believing is and that, moreover, doubting is a serious business that requires extensive training to be handled properly. People without training in a particular field do not know what to doubt and what not to doubt; or, to put it conversely, what to believe and what not to believe. I am very sorry to be undemocratic, but one man's opinion is not necessarily as good as the next man's.

To be sure, I feel uneasy about seeming to kowtow to authority in this fashion. After all, you all know of instances where authority was wrong, dead wrong. Look at Columbus, you will say. Look at Galileo.

I know about them, and about others, too. As a dabbler in the history of science, I can give you horrible examples you may never have heard of. I can cite the case of the German scientist, Rudolf Virchow, who, in the mid-nineteenth century was responsible for important advances in anthropology and practically founded the science of pathology. He was the first man to engage in cancer research on a scientific basis. However, he was dead set against the germ theory of disease when that was advanced by Pasteur. So were many others, but one by one the opponents abandoned doubt as evidence multiplied. Not Virchow, however. Rather than be forced to admit he was wrong and Pasteur right, Virchow quit science altogether and went into politics. How much wronger could Stubborn Authority get?

But this is a very exceptional case. Let's consider a far more normal and natural example of authority in the wrong.

The example concerns a young Swedish chemical student, Svante August Arrhenius, who was working for his Ph.D. in the University of Uppsala in the 1880s. He was interested in the freezing points of solutions because certain odd points arose in that connection.

If sucrose (ordinary table sugar) is dissolved in water, the freezing point of the solution is somewhat lower than is that of pure water. Dissolve more sucrose and the freezing point lowers further. You can calculate how many molecules of sucrose must be dissolved per cubic centimeter of water in order to bring about a certain drop in freezing point. It turns out that this same number of molecules of glucose (grape sugar) and of many other soluble substances will bring about the same drop. It doesn't matter that a molecule of sucrose is twice as large as a molecule of glucose. What counts is the number of molecules and not their size.

But if sodium chloride (table salt) is dissolved in water, the freezing-point drop per molecule is twice as great as normal. And this goes for certain other substances too. For instance, barium chloride, when dissolved, will bring about a freezing point drop that is three times normal.

Arrhenius wondered if this meant that when sodium chloride was dissolved, each of its molecules broke into two portions, thus creating twice as many particles as there were molecules and therefore a doubled freezing-point drop. And barium chloride might break up into three particles per molecule. Since the sodium chloride molecule is composed of a sodium atom and a chlorine atom and since the barium chloride molecule is composed of a barium atom and two chlorine atoms, the logical next step was to suppose that these particular molecules broke up into individual atoms.

Then, too, there was another interesting fact. Those substances like sucrose and glucose which gave a normal freezing-point drop did not conduct an electric current in solution. Those, like sodium chloride and barium chloride, which showed abnormally high freezing-point drops, did do so.

Arrhenius wondered if the atoms, into which molecules broke up on solution, might not carry positive and negative electric charges. If the sodium atom carried a positive charge for instance, it would be attracted to the negative electrode. If the chlorine atom carried a negative charge, it would be attracted to the positive electrode. Each would wander off in its own direction and the net result would be that such a solution would conduct an electric current. For these charged and wandering atoms, Arrhenius adopted Faraday's name "ions" from a Greek word meaning "wanderer."

Furthermore, a charged atom, or ion, would not have the properties of an uncharged atom. A charged chlorine atom would not be a gas that would bubble out of solution. A charged sodium atom would not react with water to form hydrogen. It was for that reason that common salt (sodium chloride) did not show the properties of either sodium metal or chlorine gas, though it was made of those two elements.

In 1884 Arrhenius, then twenty-five, prepared his theories in the form of a thesis and presented it as part of his doctoral dissertation. The examining professors sat in rigid disapproval. No one had ever heard of electrically charged atoms, it was against all scientific belief of the time, and they turned on their built-in doubters.

However, Arrhenius argued his case so clearly and, on the single assumption of the dissolution of molecules into charged atoms, managed to explain so much so neatly, that the professors' built-in doubters did not quite reach the intensity required to flunk the young man. Instead, they passed him--with the lowest possible passing grade.

But then, ten years later, the negatively charged electron was discovered and the atom was found to be not the indivisible thing it had been considered but a complex assemblage of still smaller particles. Suddenly the notion of ions as charged atoms made sense. If an atom lost an electron or two, it was left with a positive charge; if it gained them, it had a negative charge.

Then, the decade following, the Nobel Prizes were set up and in 1903 the Nobel Prize in Chemistry was awarded to Arrhenius for that same thesis which, nineteen years earlier, had barely squeaked him through for a Ph.D.

Were the professors wrong? Looking back, we can see they were. But in 1884 they were not wrong. They did exactly the right thing and they served science well. Every professor must listen to and appraise dozens of new ideas every year. He must greet each with the gradation of doubt his experience and training tells him the idea is worth.

Arrhenius's notion met with just the proper gradation of doubt. It was radical enough to be held at arm's length However, it seemed to have just enough possible merit to be worth some recognition. The professors did give him his Ph.D. after all. And other scientists of the time paid attention to it and thought about it. A very great one, Ostwald, thought enough of it to offer Arrhenius a good job.

Then, when the appropriate evidence turned up, doubt receded to minimal values and Arrhenius was greatly honored.

What better could you expect? Ought the professors to have fallen all over Arrhenius and his new theory on the spot? And if so, why shouldn't they also have fallen an over forty-nine other new theories presented that year, no one of which might have seemed much more unlikely than Arrhenius's and some of which may even have appeared less unlikely?

It would have taken longer for the ionic theory to have become established if overcredulity on the part of scientists had led them into fifty blind alleys. How many scientists would have been left to investigate Arrhenius's notions?

Scientific manpower is too limited to investigate everything that occurs to everybody, and always will be too limited. The advance of science depends on scientists in general being kept firmly in the direction of maximum possible return. And the only device that will keep them turned in that direction is doubt; doubt arising from a good, healthy and active built-in doubter.

But, you might say, this misses the point. Can't one pick and choose and isolate the brilliant from the imbecilic, accepting the first at once and wholeheartedly, and rejecting the rest completely? Would not such a course have saved ten years on ions without losing time on other notions?

Sure, if it could be done, but it can't. The godlike power to tell the good from the bad, the useful from the useless, the true from the false, instantly and in toto belongs to gods and not to men.

Let me cite you Galileo as an example; Galileo, who was one of the greatest scientific geniuses of all time, who invented modem science in fact, and who certainly experienced persecution and authoritarian enmity.

Surely, Galileo, of all people, was smart enough to know a good idea when he saw it, and revolutionary enough not to be deterred by its being radical.

Well, let's see. In 1632 Galileo published the crowning work of his career, Dialogue on the Two Principal Systems of the World which was the very book that got him into real trouble before the Inquisition. It dealt, as the title indicates, with the two principal systems; that of Ptolemy, which had the earth at the center of the universe with the planets, Sun and Moon going about it in complicated systems of circles within circles; and that of Copernicus which had the sun at the center and the planets, earth, and moon going about it in complicated systems of circles within circles.

Galileo did not as much as mention a third system, that of Kepler, which had the sun at the center but abandoned all the circles-within-circles jazz. Instead, he had the various planets traveling about the sun in ellipses, with the sun at one focus of the ellipse. It was Kepler's system that was correct and, in fact, Kepler's system has not been changed in all the time that has elapsed since. Why, then, did Galileo ignore it completely?

Was it that Kepler had not yet devised it? No, indeed. Kepler's views on that matter were published in 1609, twenty-seven years before Galileo's book.

Was it that Galileo had happened not to hear of it? Nonsense. Galileo and Kepler were in steady correspondence and were friends. When Galileo built some spare telescopes, he sent one to Kepler. When Kepler had ideas, he wrote about them to Galileo.

The trouble was that Kepler was still bound up with the mystical notions of the Middle Ages. He cast horoscopes for famous men, for a fee, and worked seriously and hard on astrology. He also spent time working out the exact notes formed by the various planets in creating the "music of the spheres" and pointed out that Earth's notes were mi, fa, mi standing for misery, famine, and misery. He also devised a theory accounting for the relative distances of the planets from the Sun by nesting the five regular solids one within another and making deductions therefrom.

Galileo, who must have heard of all this, and who had nothing of the mystic about himself, could only conclude that Kepler, though a nice guy and a bright fellow and a pleasant correspondent, was a complete nut. I am sure that Galileo heard all about the elliptical orbits and, considering the source, shrugged it off.

Well, Kepler was indeed a nut, but he happened to be luminously right on occasion, too, and Galileo, of all people, couldn't pick the diamond out from among the pebbles.

Shall we sneer at Galileo for that?

Or should we rather be thankful that Galileo didn't interest himself in the ellipses and in astrology and in the nesting of regular solids and in the music of the spheres. Might not credulity have led him into wasting his talents, to the great loss of all succeeding generations?

No, no, until some supernatural force comes to our aid and tells men what is right and what wrong, men must blunder along as best they can, and only the built-in doubter of the trained scientist can offer a refuge of safety.

The very mechanism of scientific procedure, built up slowly over the years, is designed to encourage doubt and to place obstacles in the way of new ideas. No person receives credit for a new idea unless he publishes it for all the world to see and criticize. It is futher considered advisable to announce ideas in papers read to colleagues at public gatherings that they might blast the speaker down face to face.

Even after announcement or publication, no observation can be accepted until it has been confirmed by an independent observer, and no theory is considered more than, at best, an interesting speculation until it is backed by experimental evidence that has been independently confirmed and that has withstood the rigid doubts of others in the field.

All this is nothing more than the setting up of a system of "natural selection" designed to winnow the fit from the unfit in the realm of ideas, in manner analogous to the concept of Darwinian evolution. The process may be painful and tedious, as evolution itself is; but in the long run it gets results, as evolution itself does. What's more, I don't see that there can be any substitute.

Now let me make a second point. The intensity to which the built-in doubter is activated is also governed by the extent to which a new observation fits into the organized structure of science. If it fits well, doubt can be small; if it fits poorly, doubt can be intensive; if it threatens to overturn the structure completely, doubt is, and should be, nearly insuperable.

The reason for this is that now, three hundred fifty years after Galileo founded experimental science, the structure that has been reared, bit by bit, by a dozen generations of scientists is so firm that its complete overturning has reached the vanishing point of unlikelihood.

Nor need you point to relativity as an example of a revolution that overturned science. Einstein did not overturn the structure, he merely extended, elaborated, and improved it. Einstein did not prove Newton wrong, but mere incomplete. Einstein's world system contains Newton's as a special case and one which works if the volume of space considered is not too large and if velocities involved are not too great.

In fact, I should say that since Kepler's time in astronomy, since Galileo's time in physics, since Lavoisier's time in chemistry, and since Darwin's time in biology no discovery or theory, however revolutionary it has seemed, has actually overturned the structure of science or any major branch of it. The structure has merely been improved and refined.

The effect is similar to the paving of a road, and its broadening and the addition of clover-leaf intersections, and the installation of radar to combat speeding. None of this, please notice, is the equivalent of abandoning the road and building another in a completely new direction.

But let's consider a few concrete examples drawn from contemporary life. A team of Columbia University geologists have been exploring the configuration of the ocean bottom for years. Now they find that the mid-Atlantic ridge (a chain of mountains, running down the length of the Atlantic) has a rift in the center, a deep chasm or crack. What's more, this rift circles around Africa, sends an offshoot up into the Indian Ocean and across eastern Africa, and heads up the Pacific, skimming the California coast as it does so. It is like a big crack encircling the earth.

The observation itself can be accepted. Those involved were trained and experienced specialists and confirmation is ample.

But why the rift? Recently one of the geologists, Bruce Heezen, suggested that the crack may be due to the expansion of the earth.

This is certainly one possibility. If the interior were slowly expanding, the thin crust would give and crack like an eggshell.

But why should Earth's interior expand? To do so it would have to take up a looser arrangement, become less dense; the atoms would have to spread out a bit.

Heezen suggests that one way in Which all this might happen is that the gravitational force of the Earth was very slowly weakening with time. The central pressures would therefore ease up and the compressed atoms of the interior would slowly spread out.

But why should Earth's gravity decrease, unless the force of gravitation everywhere were slowly decreasing with time? Now this deserves a lot of doubt, because there is nothing in the structure of science to suggest that the force of gravitation must decrease with time. However, it is also true that there is nothing in the structure of science to suggest that the force of gravitation might not decrease with time.²

Or take another case. I have recently seen a news clipping concerning an eighth-grader in South Carolina who grew four sets of bean plants under glass jars. One set remained there always, subjected to silence. The other three had their jars removed one hour a day in order that they might be exposed to noise; in one case to jazz, in another to serious music, and in a third to the raucous noises of sports-car engines. The only set of plants that grew vigorously were those exposed to the engine noises.

The headline was: BEANS CAN HEAR--AND THEY PREFER AUTO RACING NOISE TO MUSIC.

Automatically, my built-in doubter moves into high gear. Can it be possible that the newspaper story is a hoax? This is not impossible. The history of newspaper hoaxes is such that one could be easily convinced that nothing in any newspaper can possibly be believed.

But lets assume the story is accurate. The next question to ask is whether the youngster knew what he was doing? Was he experienced enough to make the nature of the noise the only variable? Was there a difference in the soil or in the water supply or in some small matter, which he disregarded through inexperience?

Finally, even if the validity of the experiment is accepted, what does it really prove? To the headline writer and undoubtedly to almost everybody who reads the article, it will prove that plants can hear; and that they have preferences and will refuse to grow if they feel lonely and neglected.

This is so far against the current structure of science that my built-in doubter clicks it right off and stamps it: IGNORE. Now what is an alternative explanation that fits in reasonably well with the structure of science? Sound is not just something to hear; it is a form of vibration. Can it be that sound vibrations stir up tiny soil particles making it easier for plants to absorb water, or putting more ions within reach by improving diffusion? May the natural noise that surrounds plants act in this fashion to promote growth? And may the engine noises have worked best on a one-hour-per-day basis because they were the loudest and produced the most vibration?

Any scientist (or eighth-grader) who feels called on to experiment further, ought to try vibrations that do not produce audible sound; ultrasonic vibrations, mechanical vibrations and so on. Or he might also try to expose the plant itself to vibrations of all sorts while leaving the soil insulated; and vice versa.

Which finally brings me to flying saucers and spiritualism and the like. The questions I ask myself are: What is the nature of the authorities promulgating these and other viewpoints of this sort? and How well do such observations and theories fit in with the established structure of science?

My answers are, respectively, Very poor and Very poorly.

Which leaves me completely unrepentant as far as my double role in life is concerned. If I get a good idea involving flying saucers and am in the mood to write some science fiction, I will gladly and with delight write a flying-saucer story.

And I will continue to disbelieve in them firmly in real life.

And if that be schizophrenia, make the most of it.

Footnotes

1 - Since this article first appeared, I have received strong objections to the use of the word from flying-saucer fanciers. Let me stress that it is not intended to apply to those who suspect that we are not yet aware of the significance of all atmospheric phenomena and that "unidentified flying objects" are therefore a reasonable object of scientific study. However, what my questioner and I meant was "flying saucer" in the sense of a spaceship carrying little green men from Venus--or the equivalent. Those who believe this, I repeat, are, in my opinion, crackpots. I. A. Back

2 - As a matter of fact, there have been cosmological speculations (though not, in my opinion, very convincing ones) which involve a steady and very slow decrease in the gravitational constant; and there is also Kapp's theory, which I described earlier in the book, which involves decreasing gravitational force on earth, without involving the gravitational constant. Back

Published by Discus Books, March, 1972, Copyright 1962