Also by Isaac Asimov in Panther Books Foundation Foundation and Empire Second Foundation Earth is Room Enough The Stars Like Dust The Martian Way The Currents of Space The End of Eternity The Naked Sun The Caves of Steel Asimov's Mysteries Nightfall One Nightfall Two I, Robot The Rest of the Robots The Early Asimov: Volume I The Early Asimov: Volume 11 The Early Asimov: Volume III Nebula Award Stories 8 (ed) Isaac Asimov The Stars in their Courses Panther Granada Publishing Limited Published in 1975 by Panther Books Ltd Frogmore, St Albans, Herts AL2 2NF First published in Great Britain by White Lion Publishers 1974 Copyright © 1969, 1970 by Mercury Press Inc Copyright © 1971 by Isaac Asimov All essays in this volume appeared in The Magazine of Fantasy and Science Fiction between May 1969 and September 1970 Made and printed in Great Britain by Richard Clay (The Chaucer Press) Ltd Bungay, Suffolk Set in Monotype Plantin This book is sold subject to the condition that it shall not, by way of trade or otherwise, be lent, re-sold, hired out or otherwise circulated without the publisher’s prior consent in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser. This book is published at a net price and is supplied subject to the Publishers Association Standard Conditions of Sale registered under the Restrictive Trade Practices Act, 1956. Dedicated to: My old friend, Lester del Rey, and to the memory of Evelyn del Rey CONTENTS Introduction A Astronomy 1 The Stars in their Courses 12 2 The Lop-sided Sun 24 3 The Lunar Honor-roll 36 4 Worlds in Confusion 48 B Physics 5 Two at a Time 62 6 On Throwing a Ball 74 7 The Man Who Massed the Earth 8 The Luxon Wall 97 9 Playing the Game 109 10 The Distance of Far 121 C Chemistry 11 The Multiplying Elements 134 12 Bridging the Gaps 146 13 The Nobel Prize That Wasn’t D Sociology 14 The Fateful Lightning 174 15 The Sin of the Scientist 186 16 The Power of Progression 199 17 My Planet, ’tis of Thee — 211 INTRODUCTION I saw the play Hair recently, largely because everyone told me I just had to see it. The music, the joy, the youthful verve, the delight — Adjectives were thrown at me as though they were darts and I was a dartboard. So I went — The first thing that happened was that the actors and actresses spread themselves all over the stage, the theater fixtures and the audience, and started mooing. ‘Aries,’ bleated someone in a husky whisper. ‘Leo,’ groaned someone else. ‘Gemini,’ ‘Libra,’ ‘Sagittarius’ came from here and there and everywhere. They were intoning the signs of the zodiac and a cold dread crept over me, for this could only mean that I was about to be immersed in a sticky sea of irrational folly. The dread was justified! There came a chant about Jupiter being in the house of Mars (or something) and everyone started a dithyramb about the ‘Age of Aquarius.’ After that, it was all downhill. Partly through natural square- hood and partly through a dogged devotion to rationality, I kept trying to make sense out of what I could hear through my shattered eardrums. I didn’t manage. When people find out now that I saw Hair> a look of holy ecstasy crosses their face (for they will lose their ticket to the land of With-It if they don’t register approval) and they say, ‘How did you like it? Wasn’t it great?’ I nod vigorously and say, ‘It was very, very loud!’ That sounds like approval so that I avoid any further discussion - and I do that without telling a lie. But what is this ‘Age of Aquarius’? I don’t know how many young people snap their fingers, sway, and look orgastic as they moan its words, but do they know what it is they’re singing? I haven’t found any who did. The question even seemed to annoy some. It was as though noisemaking is fun but knowing is a drag. So I’ll tell you what the Age of Aquarius is. The vernal equinox is the moment when the Sun crosses the Celestial Equator on its apparent motion northward, and it usually falls on March 20 on our calendar. If the Earth’s axis of rotation were absolutely motionless relative to the stars, the Sun would be at the same point in the sky at every vernal equinox. However, because of the pull of the Moon’s gravity on the equatorial bulge of the Earth, the Earth’s axis of rotation shifts in such a way that the North Celestial Pole (and the South Celestial Pole, too) marks out a circle in the sky; a circle with a radius of 23.5° of arc. It takes about 25,780 years for the poles to complete the circle. This means that every year, because of this shift in direction of the Earth’s axis, the Sun’s position at vernal equinox is displaced westward just a little bit and the time of the vernal equinox precedes the time of arrival it would otherwise have. The phenomenon is therefore called the ‘precession of the equinoxes.’ All right so far? The vernal equinox finds the Sun .crossing the Celestial Equator at a point in one of the twelve signs of the zodiac. Gradually, though, its location moves westward from one sign into the next, then into the next, and so on. In 25,780 years it will have passed through all twelve signs of the zodiac. It spends 2150 years (on the average) in each sign. Of course, there is no sharp moment of passage from one sign to the next because there are no clear boundaries between the signs, these being purely human conventions rather than astronomic fact. At the time astrology was invented by the ancient Sumerians the vernal equinox found the Sun in the constellation which we now call Taurus (the Bull). By the time the Greeks took up astrology in a big way, the Sun had moved into Aries (the Ram) at the time of the vernal equinox. The Greeks naturally began the list of signs of the zodiac with Aries, giving it domination over the period from March 20 to April 19. Astrologers today still follow the Greek fashion, applying Aries to that period of the year and the subsequent signs to the corresponding following monthly periods. Of course, about two thousand years ago, the vernal equinox edged into Pisces (the Fish), but astrologers pay no attention to the fact that all their signs are now given to the wrong months. It is the advantage of mysticism that, having no logical content, it can’t be damaged in any way by any further increase in nonsense, however great. And in the not-too-distant future, the vernal equinox will edge its way into Aquarius (the Water Carrier). It is in that sense that we are entering or are about to enter the Age of Aquarius. But what effect will the alteration have on Earthly affairs? What will the stars bring about? Nothing, of course. See the first two chapters of this book. At least, it is not the location of the Sun relative to the stars that will do anything for us or to us. But something, nevertheless, may happen (and very likely will) in the near future that will reduce all previous crises to nothingness in comparison. See the last two chapters of this book. And if so, then Hair deeply depresses me. This is no time for young people to turn from science to mysticism; from reason to emotion; from the honest sweat of concern to the loose verbalism of‘love.’ To find refuge from the miserable reality of today in the euphoria produced by drugs or mysticism (not very far apart in their effects) is to surrender - to lie down and wait for death. To be sure, science and reason have not saved us yet. Indeed, in their tragic service to the criminal forces of unreason (see Chapter 15) they have intensified our troubles. Yet there remains no substitute for them. Science may be, and has been, misused, but the proper cure for that is not to replace science by non-science and sense by non-sense - but to replace science-misused by science well- used. It is to science (and therefore to life) that I am devoted and it is the delight of the pursuit of science that I proselytize - in this book among others. A Astronomy Chapter 1 The Stars in their Courses One of the pitfalls to communication lies in that little phrase ‘It’s obvious!’ What is obvious to A, alas, is by no means obvious to B and is downright ridiculous to C. For instance, just a week ago, a storekeeper was writing out a receipt for me. He asked my name and I gave it and, as I do automatically, began to spell it, slowly and clearly. (I am absurdly sensitive about having my name misspelled.) He got the I-S-A-A-C right but by the time I had gotten as far as A-S-I- in the spelling of the last name he had raced ahead and finished it as M-O-F. ‘No, no, no,’ I said, pettishly, ‘it ends with a V, a V.’ He changed it to A-S-I-M-O-V, looked at it a moment and then said, ‘I see. You spell it the way the author does/ Well, obviously I do, but it came as a big surprise to him that I chose to do so. That’s a small item; here’s a bigger one. If anyone asks me what I think of astrology, I say something like, ‘It’s stuff and nonsense, sheerest bilge, absolute tripe. Obviously!’ Except that there’s nothing obvious about it to most people. Astrology is more popular today than ever before in history and more people than ever make a good living out of it. I have read that there are five thousand astrologers in the United States and over ten million true believers. There was a time when I could have shrugged that off and said something like: ‘Oh, well, finding that one American out of twenty is gullible and unsophisticated is no great shock.’ But the greatest popularity explosion in astrology right now is among the college students who, one might suppose, are the well-read, the intelligent, the sophisticated, the hope of the future. The question arises then: If the collegiates are taking up astrology, how can it be ‘obviously* absolute tripe? It can be tripe with no trouble at all. Consider — (1) It is fashionable right now, especially among college students, to oppose the Establishment; that is, to take up a position directly antagonistic to the one accepted by the leaders of some particular segment of society. Somje young men do it out of considered thought and honest emotion and I sympathize. (I’m rather anti-establishment in some ways myself, for all that I’m a little over thirty and am approaching late youth.) Let’s face it, though. Many college students oppose the Establishment just because it is fashionable in their set to do so and for no other reason. The opposition is quite blind as far as they are concerned and they could easily be manipulated into crew cuts, for instance, if President Nixon would only make the supreme sacrifice and grow long hair. Well, there is such a thing as a scientific Establishment, too. There is an accepted canon of scientific thought which says (among other things) that the characteristic quality of astrological lore is very like the excrement of the male bovine, and that is enough reason for many an ardent youngster to become an enthusiastic astrologian. (2) We live in troubled times. To be sure, all times are troubled (as some bland pundit is certain to say at this point) but none has ever been quite as troubled as ours is. When before have we had the inestimable pleasure of knowing that one hasty move can blow up the world in a half-hour display of thermonuclear temper tantrum? When before have we had the exciting choice of being brought to chaos and destruction by either overpopulation or overpollution within half a century without anyone being sure which will win the race? Yet in this tottering society of ours, science has no pat answers. It has only a program of procedure, a system for asking questions and testing the answers for validity - with the very good chance that said answers will prove invalid. Opposed to this are various systems of mysticism which give answers loudly, clearly and confidently. Wrong answers, to be sure, but what’s the difference? The sad thing for us rationalists is that the vast majority of the human race would rather be told that ‘Two and two is five and make no mistake about it,’ than ‘I think it is possible that two and two may be four.’ (3) College students are no more a homogeneous group than is any other large classification of humanity. Not all of them are interested in science; not all of them are truly bright. Many of them are just bright enough to discover that what counts in this phony world is merely the ability to sound bright - an ability which has carried many men to high political office. It is easier, they soon learn, to sound bright in some subjects than others. It is, for instance, just about impossible to sound bright in mathematics or the physical sciences without actually being bright. The facts, observations and theories are too well established. There is a firm consensus and you have to know a great deal about that consensus before you can sound bright, and for that you have to be bright. The consensus is shakier in the social sciences; still shakier in the humanities; and in matters such as mystical Eastern cults (just to take an example) there is no consensus at all. Someone who spouts nonsense in chemistry will be caught at once by any high-school student who knows something about chemistry. Someone who spouts nonsensical literary criticism, however, can be spotted only with difficulty. Indeed, what are the criteria for nonsense in literary criticism? Do you know? Does anyone? As for mysticism, hah! Your bluff in this field cannot possibly be called. Make up a chant such as: Toilet Tissue, Toilet Tissue, Toilet, Toilet, Tissue, Tissue— Tell everybody that this chant repeated 666 times (the number of the beast) will induce inner serenity and cosmic consciousness and you will be believed. Why not? It sounds no worse than anything else in mysticism and you will become a highly respected swami. To put it as briefly as possible: Many college students are taking up astrology in a big way because (1) it is the in thing to do, (2) it gives them a delicious, if false, sense of security, and (3) it gives them a passport to phony inteliectualism. And none of that is at all inconsistent with astrology being tripe. The funny part is that astrology started off as the best science man could find. In man’s cultural dawn, when the Universe seemed a whimsical place and the gods were constantly hitting one over the head without good reason, there had to be some system for finding out what those troublesome divinities wanted. Desperately, priests sought answers by watching the flight of birds, the shape of the livers of sacrificed animals, the fall of dice and so on. These events were essentially random in nature, but early man did not recognize the principle of randomness. (Many of our contemporaries don’t either.) All events were either man controlled or god controlled, and if a particular event was not man controlled it therefore had to be god controlled. So people study tea leaves and head bumps and palm creases even today. A great advance was made by certain priests (probably in Sumeria, a land which later became Babylonia, then Chaldea, Mesopotamia and finally Iraq). If I may be allowed to reconstruct what their reasoning may have been, here it is. The gods, they may have argued, could scarcely be so inefficient and so wasteful in time and effort as to make special messages for each occasion. How ungodly to take the trouble to create particular livers or to send a particular bird flying in a particular direction, or to go to the trouble of thundering in this quarter of the sky or that, every time there was something to say. A truly great god would scorn such trivia. He would instead create some natural phenomenon that was continuous and yet complex - a kind of moving finger that would steadily write the history of the world in all its facets and would act as adviser for man. Instead of man depending on the uncertainties of special revelation, he would merely have to work out the laws that governed the continuous but orderly complexity of the natural phenomenon.* * If the early astrologers argued in this fashion, and very possibly they did, they were imbued with the spirit of science and I honor The one natural phenomenon that was absolutely steady and inexorable, that could apparently be set into motion once and for all, was the movements of the heavenly bodies. The Sun rose and set day after day and, at its daily peak, shifted north and south in a slower rhythm. The Moon rose and set day by day and changed phases in a slower rhythm. The mathematical rules describing these changes were not simple, but were not so complex that they could not be worked out. Furthermore, these shifts clearly affected the Earth. The Sun caused the alternation of day and night by its rising and setting, and the slower alternation of seasons by its movement north and south. The Moon’s rising and setting (along with its phases which were easily seen to be related) gave successions of lighter nights and dimmer ones. (Its phases were also related to the tides - a fact of extraordinary importance - but for various reasons this wasn’t firmly noted till the end of the seventeenth century.) Obviously, if the shifting Sun and Moon could affect conditions on Earth, then an ‘astrologic code’ must exist. If you can predict the change in shifts in the heavens, you ought to be able to predict the change in conditions on the Earth. Of course, it is rather trivial to predict that tomorrow morning the Sun would rise and the Earth would light up, or that the Moon was waning and the nights would grow dark, or even that the noonday Sun was shifting southward and that cold weather was therefore on its way. All that was simple enough for ordinary men to handle but it lacked detail. Would there be enough rainfall? Would the crops prosper? Would there be war or pestilence? Would the queen have a baby son? For that the sky had to be studied in greater detail. We will never know what early observer or observers began making systematic observations of the position of the Moon and the Sim against the starry background. The thousands of stars maintained their relative position night after night, year after year, generation after generation (so that they were called them. No scholar can be maligned for being wrong in the light of the knowledge of a later period. If he strives for knowledge in the terms of his own time he is a member of the brotherhood of science. ‘fixed stars’), but the Sun and Moon shifted position with respect to them. Eventually, the Greeks called them ‘planets’ (‘wanderers’) because they wandered among the stars. Both Moon and Sun took a certain fixed path among the stars, the two paths being fairly close together. They traveled at different rates, however. While the Sim made one complete circuit around the heavens, the Moon managed to make twelve. (Actually twelve and a fraction, but why complicate matters?) It was useful then to mark off the path by means of easily detected signposts - a development probably started by the Sumerians but brought to perfection by the Greeks. Suppose you take a strip of stars in a circle around the heavens; the particular strip of stars that contains the paths of the Sun and the Moon; and divide it into twelve equal parts or ‘signs.’ Start the Sun and the Moon in the same place in one of those signs. By the time the Moon has gone around once and returned to the sign, the Sim has moved one twelfth of the way around and shifted into the next sign. Another circuit of the Moon would find the Sun shifting into the next sign after that. As an aid to the memory, draw patterns among the stars in each sign, preferably patterns that resemble familiar animals, and you have twelve constellations making up the ‘zodiac’ (‘circle of animals’). Once you start to study the zodiac carefully, you are bound to discover five bright stars that are not fixed but that wander around the zodiac as the Sun and Moon do. These are five more planets, in other words, and we know them today as Mercury, Venus, Mars, Jupiter and Saturn. These new planets add immeasurably to the complications of the heavens and, therefore, to the potential of the ‘astrologic code.’ Some of them move quite slowly. Saturn, for instance, makes only one complete circle of the sky while the Moon is making 360 of them. What’s more, while the Sun and Moon always move from west to east against the background of the stars, the other planets sometimes shift direction and briefly move east to west in what is called ‘retrograde motion.’ Saturn does it no less than twenty-nine times during the course of a single revolution. I stress the point that the early astrologers were not fakers. If they had been charlatans, it would have been much easier to stick to watching birds and livers. Establishing the background of astrology meant watching the skies night after night, making painstakingly accurate observations and, in short, working one’s head off. And what they discovered was factual and valuable. Their observations represented the beginnings of real astronomy and have remained a completely valid description of the machinery of the solar system (relative to a stationary Earth) to this very day. Where the astrologers went wrong was not in their description of the heavens but in their working out of the ‘astrologic code.’ And even here they must have done their best to be rational. Where could you find a clue to the code? Suppose there was an event in the heavens that was extremely rare. Would that not mean that any equally rare event that followed on Earth would be related to it? And could not one learn something from the relationship? For instance, suppose there was an eclipse. Suppose it was one of those rare occasions when the Moon was slowly blotted out of the heavens; or one of those even rarer occasions when the Sun was. Would not that be followed by some equally notable event on Earth? The question almost answered itself, for eclipses struck absolute panic in the hearts of all who watched, and understandably so. It is routine to laugh at that panic, but don’t. Suppose you knew very well that your life depended on the Sim and suppose you watched the Sun slowly fading before an encroaching blackness for reasons you could not explain. Would you not feel the Sun was dying? And that all life would die with it? (Consider that in our own ‘sophisticated5 time it is only necessary for some solemn idiot to proclaim that California will fall into the Pacific Ocean on 3 P.M. of next Thursday to cause a quick exodus of uncounted thousands from that state.) Well, then, if an eclipse is so rare and frightening a phenomenon, it is very easy and almost inevitable to argue that its consequence must be an equally rare and frightening event on Earth. In short, an eclipse must portend disaster.* But never mind theory. Does disaster follow an eclipse in actual fact? Sure, it does. In any year with an eclipse there is some catastrophe somewhere and this is easy to see since in every year, eclipse or not, there is some catastrophe somewhere. Astrologers seize upon the catastrophes that follow eclipses. Unscientific? Certainly. But very human. (In this very enlightened year in which we live, try arguing with someone who firmly believes that lighting three on a match is unlucky. Tell him that misfortunes happen even when only lighting two on a match and see how far you’ll get.) As it happens, it could not have taken very long for the early astrologers to learn the cause of eclipses. They would note that the Moon was eclipsed whenever it was on the side of the Earth directly opposite the Sun, and therefore in the Earth’s shadow. They would note that the Sun was eclipsed whenever it and the Moon were precisely in the same spot in the sky and we were therefore in the Moon’s shadow. By carefully calculating the motions of the Moon and the Sun, it was possible to predict lunar eclipses in advance without too much trouble. (Some think that the ancient Britons used Stonehenge for that purpose in 1500 B.c.) Solar eclipses were harder to calculate but eventually they, too, could be handled. It is easy to see that astrologers would be tempted to keep their methods secret. The common folk wouldn’t be able to follow the calculations anyway and would be annoyed if they were asked to. Besides, the astrologers probably found their social standing greatly enhanced and they managed easily to keep it so without letting on that anyone could do it if he would but take the trouble to master the mathematics involved. Of course, it had its risks. A Chinese legend reports that in very ancient times an eclipse came to the capital without warning because the royal astronomers Hsi and Ho, preoccupied with a drinking bout, somehow neglected to let it be known that * The very word ‘disaster’ is from a Greek term meaning, essentially, ‘evil stars.’ it was going to happen. After the emperor had gotten over his imperial fright at the unexpected event, the suddenly sobered astronomers were led off to execution and all agreed that it was richly deserved. An eclipse could have more beneficent results, too. Farther west, in ancient times, the Sim’s disc was encroached upon by darkness, little by little, over a field of battle in Asia Minor. The armies of Lydia on the west and Media on the east stopped fighting and peered at the vanishing Sun. The few minutes of eclipse-night came and when they had passed the opposing generals could do only one thing. They signed a treaty of peace and went home. Lydia and Media never fought again, for they knew the anger of the gods when they saw it.1 As it happens, modem astronomers can calculate the exact date of the eclipse of the Sun that took place in Asia Minor at about that time. It was on May 28,585 B.C., SO that the Lydian- Median battle is the earliest event in all history, other than the mere fact of an eclipse, that can be pinned down to an exact day. The Greek philosopher Thales was supposed to have predicted the eclipse, though not to the exact day - merely that one would take place that year. He is supposed to have traveled in Babylonia in his youth and he probably learned the prediction trick from astronomers there. There was another astronomical event that broke the quiet routine of the heavens, and that was the coming of a comet. It created even worse terror than that caused by an eclipse, taken over all, for several reasons. Whereas an eclipse came and went in a relatively short period of time, a comet would remain in the sky for weeks and months. Whereas an eclipse involved perfectly regular shapes (arcs of circles), comets had weird and ominous forms - a fuzzy head with a long tail that might look like a sword suspended over the Earth, or the disordered hair of a shrieking woman. (The very word ‘comet’ is from a Greek word for ‘hair.’) Finally, whereas an eclipse could be predicted even in ancient times, the coming of a comet could not be. A system for predicting the arrival of some comets wasn’t worked out till the eighteenth century. Comets were even surer indications of catastrophe then than eclipses were, and were indeed followed by catastrophes for the same reason. Thus in 1066, the comet we now call Halley’s Comet appeared in the sky just as William of Normandy was making ready to invade England. It predicted catastrophe and that is exactly what came, for the Saxons lost the Battle of Hastings and passed under the permanent rule of the Normans. The Saxons couldn’t have asked for a better catastrophe than that. On the other hand, if the Saxons had won and had hurled William’s expeditionary force into the Channel, that would have been catastrophe enough for the Normans. Whichever side lost, the comet was sure to win. With eclipses and comets serving so excellently to predict events on Earth, the principle of the ‘astrologic code’ seemed well established and the technique, too, for it seemed to work on the principle of similarity. A disappearing Sun bespoke disappearing prosperity; a comet with a tail like a sword bespoke war, and so on. With the Greeks, democracy invaded astrology. In the East, the philosophy of the oriental monarchies, where only the king counted, kept astrology the handmaiden of high political affairs. Among the individual-centered Greeks, the personal horoscope came into use. One could imagine them arguing that since the Sun was the brightest of the planets (using the word in the ancient sense) it had the most to do with the individual. In which sign was the Sun at the moment of that individual’s birth? If it was in the constellation of Libra (the Scales), ought he not to be of even and judicious temperament; if it was in Leo (the Lion), ought he not to prove a brave warrior? If you stop to think that the ancients thought the heavenly bodies were small objects quite close to the Earth, and the constellations somehow really represented the things they seemed to represent, it all makes a weird kind of sense. Even so, there were two important groups in the palmy days of the Greeks who opposed astrology. The Greek philosophical school of Epicureanism opposed it because their view of the Universe was essentially an atheist one. They felt the heavenly bodies moved purposelessly and that no gods existed to weave meaning into their motions. The other group was that of the Jews, who were unusual among the people of the time, for being cantankerously monotheistic. They were not scientifically minded and they used no rational argument to oppose astrology. (They would have been unspeakably horrified at the Epicurean reasoning.) It was just that those who supported astrology were pagans and considered the planets to be gods and this was anathema, on principle, to the Jews. Yet even the Jews were not wholly uninfluenced by astrology. The older writings that appear in the Bible were carefully edited in Greek times by pious rabbis intent on wiping out unedifying traces of a polytheistic past - but the erasures weren’t perfect. Thus, on the fourth day of Creation, the Bible states: ‘And God said, let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days and years.’ (Genesis 1:14.) That little word ‘signs’ is an astrologic hangover. A clearer one is to be found in the Song of Deborah, one of the oldest passages in the Bible, an ancient poem too well known to endure much tampering. After the defeat of Sisera, Deborah sang: ‘They fought from heaven; the stars in their courses fought against Sisera.’ (Judges 5:20.) Neither the Epicureans nor the Jews prevailed, however. Astrology continued and was exceedingly popular in the seventeenth century when modern astronomy came gloriously into its own. In fact, some of the very founders of modern astronomy - Johannes Kepler, for instance - were astrologers, too. But by the end of the seventeenth century, with a true picture of a heliocentric solar system established, astrology finally became a pseudo science. It passes human understanding to suppose that the vast Universe we now recognize is arranged only as a key for our own insignificant dust speck. That so many men and women believe it is, just the same, is a remarkable tribute to the manner in which human folly can triumph over all. Still, science has its prestige even among its enemies. There are those devotees of astrology who know just enough about real astronomy to seek some legitimate scientific rationale for the pseudo science. And such is the ingenuity of man, particularly when it is misapplied, that such a rationale (extraordinarily weak but a rationale, nevertheless) can actually be found. I’ll talk about that in the next chapter. Chapter 2 The Lop-sided Sun Last fall, a large-tirculation magazine wanted to get an article on eclipses that they could run in conjunction with a solar eclipse that was to take place the following spring over the United States, It occurred to the magazine to get me to do the job and you can bet I was willing to do so. Writing about eclipses was apple-pie-and-mother for me, and I had never appeared in the pages of this particular magazine and I wanted to do so. But the fact that I had never done anything for the magazine was naturally a source of insecurity for the editors. They wanted to talk to me and asked me to come visit their offices. I did so, and listened to them explain very carefully what they wanted. I nodded and said I understood and that I would try to strike the very note they were asking for. But then one of the editors thought a bit and said, ‘Could you describe a total eclipse for us? How would it look? What would you see? What is it like?* ‘All right,* I said, and calling on the skills that years and years of writing had made second nature, I described a total eclipse in the most moving imaginable terms. By the time I was through I had them (and myself) all but dissolved in tears. ‘Good,* they said. ‘Write that article for us, just as you told it.* I did, and they liked it (and said so), paid for it, published it and all was absolutely well. In fact, during the whole transaction, there was only one moment during which a bit of nervousness made itself felt. While I was describing the total eclipse in poignant detail, I was uneasily aware that all could be ruined by a single, simple question. What if someone in my audience had said, ‘But, Dr. Asimov, have you ever seen a total eclipse?* For of course I hadn’t. But then, as I told you, I called upon my writing skills and I was a fiction writer to begin with. Naturally, I must not allow a narrow escape like that to shake my nerve so, like the thrown rider climbing back on the horse, I will now turn, unrepentant, to the Sun again. To anyone who is so foolish as to try to look at the Sun in its glory, it must seem to be an eternally featureless circle of brilliant white light. Indeed, there have been theologians who maintained that if it weren’t exactly that, it would represent a flaw in the perfection of God’s handiwork, and who therefore resisted any suggestion that such flaws might exist. It was one of the unsettling aspects of Galileo’s astronomical discoveries that, in 1610, he reported the existence of spots on the face of the Sun. Once that troubling fact was reported, and despite considerable clerical shock, others saw them at once. Indeed some spots are huge enough to be made out with the unaided eye. When the Sun is very close to the horizon on a particularly clear day, and is ruddily dim enough to be looked at without harm, large sunspots can sometimes be made out. Sunspots are easy to see because they are regions that are cooler than the surrounding solar surface and that therefore seem dark in comparison. Black-on-white is impossible to miss. But what about the reverse situation? What if there are local regions of the Sun’s surface that are hotter than surrounding areas? If so, they would be unusually bright, but whiter-on- white is a lot harder to see than black-on-white and, in point of fact, no one saw hot regions on the Sun for two and a half centuries after the cool regions were detected. The honor of the later discovery belongs to Richard Christopher Carrington, an English astronomer who kept painstaking track of sunspots over prolonged periods of time, working out the exact time of rotation of the Sun at different latitudes. (A gaseous body does not rotate all in one piece as a solid body perforce must.) In 1859, Carrington noted a short-lived, brilliant flare-up on the face of the Sim. It was as though a tiny star had made itself visible on that face for some five minutes. Carrington reported it and suggested a cause. At this time, astronomers were considering the possibility that the Sun might use as the source of its radiation the kinetic energy of impacting meteors, and Carrington felt he had been lucky enough to see the impact of a particularly large meteor. It was a very interesting guess, but wrong. If whiter-on-white is hard to see in general, this may not be so at all wavelengths. That is, the general increase in brightness in a particular hot spot may, for some reason, be greater at some wavelengths than others. If the Sun were viewed by the light of the wavelength particularly affected, a flare-up that would be difficult or even impossible to see over the entire spectrum might suddenly become unmistakably conspicuous. In 1889, the American astronomer George Ellery Hale invented the ‘spectroheli ograph,’ a device whereby the Sun could be photographed by light coming through a spectroscope so arranged that all light, except over a small stretch of wavelengths, is excluded. In that way, the Sun could have its picture taken by hydrogen light or by calcium light. Seen by calcium light it was easy to find out, for instance, that there were calcium-rich regions here and there on the Sun, standing out like clouds in a summer sky on Earth. Using the spectroheliograph, one tends to get static pictures of the Sun and misses short-lived events; that is, it is difficult to tell whether a particular spot on the photograph has just come into being or is soon to pass - unless you take a number of closely spaced stills. In 1926, Hale (still alive, still active, still ingenious) devised a modification of the instrument that enabled one to watch events by the light of a spectral line over a period of time. This ‘spectrohelioscope5 made it a lot easier to detect swift changes. Before the 1920s were out, then, it became apparent that, by hydrogen light, there were flare-ups rather commonly associated with sunspots. There were what seemed to be explosions, sudden flashes of hot hydrogen, that might be at full heat for five to ten minutes and be utterly gone after half an hour to an hour. These were * solar flares5 and, looking backward, it was understood that what Carrington had seen seventy years before had been an unusually bright one. When a flare is on the side of the Sun facing us, there’s not much to be seen but a brightening and spreading patch. Occasionally, though, one catches a flare coming into being at the edge of the Sun. Then one can see, in profile, a huge surge of brilliant gas climbing at a rate of six hundred miles a second or so, and reaching a height of some five thousand miles above the Sun’s surface. Small flares are quite common and in places where there is a large complex of sunspots, as many as a hundred a day can be detected, especially when the spots are growing. Very large flares of the kind that approach visibility in white light (like Carrington saw) are rare, however; and only a few occur each year. The spectra associated with these flares indicate temperatures of up to 20,000° C. as compared with 6000° C. for the undisturbed surface of the Sim and 4000° C. for the dark center of sunspots. Solar flares are important in connection with a more general activity of the Sun’s surface. Energy is somehow transferred from the Sun’s glowing surface to the thin solar atmosphere, or ‘corona.’ That energy must be distributed among the atoms of the corona which are far fewer in number than are those of the surface. This means that the energy per atom is far higher in the corona than on the Sun’s surface and ‘energy per atom’ is what we mean by ‘temperature.’ It is not surprising then, that where the surface temperature of the Sun is 6000° C., the coronal temperatures can be as high as 2,000,000° C. The intensity and wavelength of radiation from any body depends upon its temperature and the corona delivers more radiation (per unit mass) than the Sun’s surface does. It is only because the corona has so small a mass that it seems so faint. What’s more, coronal radiation is far more energetic than surface radiation is, and it is from the corona that solar X rays arise. Nor is electromagnetic radiation all that flows out of the Sun. The turbulent solar atmosphere sends matter streaming upward and small quantities of it inevitably manage to escape even the Sun’s tremendous gravity. There is a constant drizzle of particles moving outward and, apparently, lost to the Sun forever. In absolute terms the mass of particles lost in this fashion is enormous by Earthly standards, for it comes to a million tons per second. By Solar standards it is nothing, for if this loss were to continue indefinitely at its present rate, it would take six hundred trillion years for the Sun to lose 1 per cent of its mass. These particles, spreading outward from the Sun in all directions, make up the so-called ‘solar wind.’ The solar wind extends to the Earth and beyond, of course, but the Earth’s small globe intercepts only a tiny part of all the particles cast out by the Sun. Of the million tons of particles lost by the Sun each second, about three fourths of a pound strike the Earth. This is not much in terms of mass, but it means that every second something like a hundred trillion solar particles reach the vicinity of the Earth. If the Earth were without atmosphere or magnetic field, those particles that reach the vicinity of the Earth would go on to strike the surface of the planet. They strike the surface of the Moon, for instance, and the samples of rock brought back by the astronauts contain quantities of helium that can have originated only in the solar wind. The particles in the solar wind are naturally representative of the material in the Sun. The Sim is very largely hydrogen, with most of what is left being helium. At the temperature of the corona through which the solar wind passes, atoms of hydrogen and helium are broken down to a mixture of atomic nuclei and electrons. The hydrogen nucleus is a proton and the helium nucleus, an alpha particle. The protons are much more massive than the electrons and much more numerous than the still more massive alpha particles, and if both mass and number are taken into account, it is clear that the major components of the solar wind are its protons. Any increase in the density of the wind due to something happening back on the Sun may be called a ‘proton event.* Since the Earth has a magnetic field, the electrically charged particles of the solar wind (one positive charge for protons, two for alpha particles and one negative charge for electrons) are deflected along the magnetic lines of force. That means they move in a tight spiral from one magnetic pole to the other, back and forth over and over. It is these moving particles, held in place by the magnetic lines of force that make up what used to be called the Van Allen belts but are now more often called the ‘magnetosphere.’ The magnetosphere dips closest toward the Earth’s surface at the magnetic poles and it is there that the charged particles most easily leak out of the magnetosphere and into the Earth’s upper atmosphere. The interaction of the charged particles and the atoms of the upper atmosphere produces the shifting curtains and streamers of the aurora. Well, then, what happens when a flare lights up a portion of the solar surface? There is a localized rise in temperature and a localized increase in turbulence that result in the sending of a blaze of energy and a rash of particles into the corona immediately above the flare. The coronal temperature rises and there is an increase in its production of ultraviolet radiation and X rays at the affected spot. The additional rush of particles also produces a kind of gust in the solar wind so that the solar flare could, in effect, result in a proton event. The intensification of the solar wind above a particularly large flare can be so great that the speeding protons become energetic enough to count as mild cosmic rays. If the solar flare shoots up into the Sun’s atmosphere in the direction, more or less, of Earth, there is a burst of energetic radiation toward us that reaches our planet in minutes, and there is also a gust in the solar wind that reaches us in a couple of days. When that gust of solar wind reaches the Earth’s magnetic field, there is a sudden brightening and extending of the aurora. The radiation from the flare and the subsequent flood of charged particles upsets the situation in Earth’s upper atmosphere. It may produce wild static in electronic equipment or it may wipe out (temporarily) some of the charged layers in the upper atmosphere, causing radio waves to pass upward into space instead of being reflected downward toward the ground. Radio transmission can then lade out altogether, and radar may grow useless. These manifestations are usually termed ‘magnetic storms* because one of the symptoms is a wild irregularity of the needle of the magnetic compass in response to all the jolts being undergone in the region of the magnetic poles. Variations in the magnetic compass and intensification of the aurorae are interesting but not, in today’s society, very significant. The possible disruption of radio transmission is another matter. It can seriously annoy our electronically oriented population and industry. At particularly pathological moments (say, during wars or threats of war) the possibility that radar may go awry, that radio-controlled missiles may wander off course, and that communications of all sorts may be distorted or destroyed can be a serious source of worry. Then, too, astronauts in space or on the Moon’s surface may be caught in the aftermath of a flare, be subjected to an intense gust of the solar wind and suffer radiation sickness. With this in mind, it would naturally become a matter of great interest to be able to predict the coming of flares long enough in advance to keep men out of space, to protect men on the Moon, and to set up alternate methods of communication in a war zone. It would help if we knew what caused flares in the first place, but we don’t. Since flares are characteristically found in connection with sunspots, we might suppose that if we knew what caused sunspots, we might deduce what caused flares - but we don’t know what causes sunspots, either. But suppose we reason like this— Sunspots represent an asymmetry on the Sun. A sunspot forms at some particular place on the Sun’s surface and not on others. Why should that happen? Why shouldn’t all parts of the Sun’s surface be alike? After all, the Sun is a nearly perfect sphere and, as nearly as we can theorize, it is radially symmetrical. That is, working from the center outward, properties change equally no matter what direction we choose. On Earth, we have weather. We have storms developing in one place and calm in another; zephyrs here and tornadoes there; drought yonder and floods elsewhere. But all this is the result of a tremendous asymmetry - the fact that one side of the Earth faces the Sun’s heat and the other does not, at any given time, and that even on the side facing the Sun there are variations in the length of time of exposure and the direction from which the Sun’s rays are received. On the Sun, however, there is no such overwhelming asymmetry in evidence. Why, then, does it have 'weather’ in the form of sunspots? To be sure, the Sun rotates, so there is a difference with respect to the centrifugal effect as related to latitude. There is no centrifugal effect at the pole and maximum effect at the equator, with intermediate values in between. The rotation may also set up asymmetries in the deeper layers of solar material, too. It would not be surprising then if the sunspot appearance was somehow connected with latitude, and that turns out to be correct. Sunspots tend to appear only between 5° and 30° north and south latitude. Within that latitude range there is a complex regularity. The sunspots increase in numbers to a maximum, then decrease to a minimum, then increase to a maximum again, with a period of eleven years. Immediately after a minimum, spots appear at about 30° north and south latitude. Then, as they increase in numbers from year to year, they tend to shift toward the equator. At periods of maximum, they are at an average latitude of 15° and continue to shift toward the equator as they decrease in number again. As the cycle dies within 5° of the equator, a new set begins to appear at 30°. Nobody knows why the cycle works in that way, but can it be that it is the result of some asymmetry more complicated than that introduced by the Sun’s rotation? If so, where might that asymmetry come from? One possibility is that it is imposed from the outside and the finger of suspicion points to the planets. But how can the planets affect the Sun? Surely only by way of their gravitational fields. Those fields might raise tides on the Sun and make it lopsided. The Moon, for instance, raises tides on the Earth because the side of the Earth near the Moon receives a stronger lunar pull than the side on the opposite side of the Moon. It is this difference in pull that produces the tidal effect. The size of the tidal effect depends upon three things. First, upon the mass of the tide-producing body, of course, since the greater the mass, the greater the gravitational pull. Second, upon the diameter of the body experiencing the tides, since the greater the diameter, the greater the difference in gravitational pull experienced on opposite sides. Third, upon the distance of the body experiencing the tides from the tide- producing body. The greater the distance, the weaker the gravitational pull of the latter on the former, and the smaller the difference in pull on the two sides of the former. Taking all these factors into account, we can set up the following table: Relative tidal effect 7000 3200 1 The tidal effect of the Earth on the Sun is only a ten- thousandth of that of the Sun and Moon combined on Earth, but perhaps this effect, though tiny, is not entirely insignificant. What about the tidal effects of other planets? Taking the Earth’s tidal effect on the Sun as unity, it isn’t difficult to work out the relative tidal effects of the other planets on the Sun. Here are the results: Relative tidal The four greatest tidal effects, then, are those of Mercury, Venus, Earth and Jupiter. All the remaining planets put together produce a tidal effect about a fifth that of Mercury, the least of the big four. We might therefore give the name ‘tidal planets’ to Mercury, Venus, Earth and Jupiter. As these planets circle the Sun, each produces a pair of tiny bulges on die Sun (one bulge on the side of the Sun toward itself, another on the opposite side). These bulges may be tiny indeed, measured perhaps only in centimeters, but even that much rise and fall of the Sun’s vast surface could be significant. With four separate bulges on each side of the Sun, continually changing positions with respect to each other as the planets move, there might just conceivably be some crucial moment when, as a result of the combination of bulges, a particular section of the Sun’s surface rises or falls with unusual speed. Can it be, then, that it is at that point and at that time that the sequence of changes that produces a sunspot is set in motion? Perhaps, too, there is some long-range pattern in the shifting bulges that accounts for the sunspot cycle and the regular shift in latitude. Of course, it is hard to try to correlate the appearance of a particular sunspot with a particular combination of tidal bulges. The appearance is too slow. But what about flares? Flares come and go quickly and sizable flares are not very common. Can large flares be correlated with not-very-common planetary positions? Perhaps! Dr. J. B. Blizard, a physicist at the University of Denver, has studied the connection of proton events with planetary conjunctions; that is, with situations in which two or more of the tidal planets take up such positions that a line through them points toward the Sim. The tidal effect would then add up; there would be an unusually high bulge in the Sun’s surface and perhaps if that passes near a region of sunspot turbulence, it would set off a flare. In any case, over the period between 1956 and 1961, Blizard noted a sufficient number of positive correlations; that is, of flares coming near the time of conjunction, to make matters look interesting. He calculated that there was only one chance in two thousand of the correlations being just coincidence. What’s more, he began a series of predictions of the occurrence of flares in the future, supposing them to come at the time of later conjunctions (which are easy to calculate) and achieved 60 per cent accuracy. And here, then, is where we can return to the subject of astrology, which I discussed in Chapter 1.1 said in that chapter that astrologers would naturally seize on any scientific rationale, however faint, for justifying their folly, and I suspect that Blizard’s work will be right up their alley. For years now, astronomers and non-astronomers have wondered about the effect of the sunspot cycle on Earth. Was there more solar radiation at sunspot minimum? Was there sufficiently more, perhaps, to produce droughts, cut down the food supply, affect prices, start inflations or depressions, make wars more likely, and so on? When flares were discovered, they seemed even more likely than sunspots themselves to affect Earth. After all, they bathed the atmosphere in charged particles and that might affect rainfall which in turn might affect crops which in turn might affect— Besides, who knows what more subtle changes might rise and fall with the quantity of charged particles striking Earth? Now comes along Dr. Blizard who makes it seem that the rise and fall in the solar wind may depend upon planetary position and ‘planetary position’ is a magic phrase to astrologers. I can look forward to the following chain of reasoning. 1 - The planetary positions control the occurrence of solar flares. 2 - Through the solar flares, the planet