9. Science Then and Now
Suppose that in some magic way an unborn individual could be told that he is going to live for about three fourths of a century. In order to have the richest possible experience, when would he like to have that period begin? The answer would of course depend on the nature and range of the interests of the person in question. Some would, understandably, choose the age of Pericles. Some surely would choose the Elizabethan age. If the person is to be chiefly interested in science, then I think he might sensibly choose my own period, beginning with 1894. Benjamin Franklin, looking ahead with remarkable vision in 1780, wrote to the English clergyman and chemist Joseph Priestley (1733-1804), "the rapid progress science now makes occasions my regretting sometimes that I was born too soon." I have no similar regret. I had the good luck to be born at the right time.
Why do I think I was born at the right time? For a person whose interests and activities have been primarily in science, the answer is bound to be, at least in part, because of the exciting and majestic developments in science during my lifetime.
But these scientific developments do not constitute the complete answer to the question just posed. Important and
fascinating as science is, there are numerous other concerns of men that are essential to a good life. At the beginning of this book, I mentioned that the front page of the issue of The New York Times on the day of my birth contained essentially no national news, and no international news whatsoever. I was born into what, in retrospect, seems a somnolent world, whose leaders acted like sleepwalkers. The savage wars, the social tumult, the frenzied unrest of some of the years since I was born have been in many ways frightfully disturbing. But all this is a sign of life and vigor, of sensitivity, of concern for the human condition, and it is, I believe, a sign pointing toward ultimate progress. Thus in addition to being thankful for living through some of the proudest days of science, I am also thankful for living at an exciting time of political and social movement. Dark as the prospect has often seemed, I have faith that the world has, during this period, been groping toward the light, and I appreciate having been able to sense and observe all this movement.
The more serious and significant aspects of the progress of science during my lifetime could, of course, only be described in technical terms. To the trained scientist, the significant advances are likely to be improvements in complicated and abstract basic theories. These improvements give the theories greater precision, broader application, and increased esthetic grandeur. These improvements are often too technical and too abstract to seem impressive to the nonscientist. But it is just these deep and abstract improvements in basic theories which presently give scientists a more effective control over natural forces, and which thus lead to the technological improvements that touch and serve everyone.
Thus it is brought about that people in general are likely to be aware of scientific progress as evidenced by its by-products, rather than aware of the progress in the inner core of scientific thought. This is a great pity, for that inner core of scientific thought is one of the most beautiful and most impressive products of the imaginative human mind. As science education improves in all levels of our schools, and as competent public interpretation of science advances, our society should approach an improved state in which more and more of the marvelous inner structure of science can be appreciated by everyone. In the meantime, it remains embarrassingly true that the practical results of applied science are, for many persons, the basis upon which their estimates of science necessarily rest. So, regretfully, I accept the fact that an effective way of giving a generally understandable description of the way science progresses over a period is to cite the improvement, over that period, of the practical procedures or devices, aids to everyday living, made possible by scientific advance.
I will therefore start by reminding the reader of some technological changes which science has made possible during the past seventy-five years, these being changes that affect all of us.
I am confident, from having conducted a small private
I will presently cite some arithmetical facts, but all of the contrast between transport in 1894 and transport now is not to be captured in numbers. When I was a small boy my maternal grandparents lived in a tiny village about fifty miles from our home; and once or twice each year, my father would decide to risk driving our automobile that distance. This journey was not undertaken lightly. In preparation, my father would clean and reset the spark plugs, would check on the supply of patches and cement for mending an inner tube, and would carefully check up on the carbide system which supplied the headlights with gas, should darkness overtake us. The fifty-mile journey, with time out for a picnic lunch and for roadside repairs, sometimes took the better part of a day. But what is a day's journey now? The last time my wife and I came home from Europe, we had breakfast in Paris and dinner in our own house in Connecticut.
All the advantage in transport, however, is not to be credited to today. We can now, to be sure, travel much faster than we used to. But we have lost something in convenience, and in comfort, and in style. One of the thrills of my youth was a trip on a train. A meal in a dining car, at the turn of the century, was a glamorous, elegant, and altogether pleasant affair. To be sure, one now has gourmet meals at an altitude of over 30,000 feet, and an airline is apologetic if it does not broil your steak in flight, and to order. But the valley of western Connecticut where I live now has passenger train service only on weekends; and the occasional train is pretty shabby-looking.
The speed of modern transport is indeed impressive, especially to one who recalls the flights at Kitty Hawk in 1903. But, surprisingly, the 600 miles per hour of the present-day commercial jet aircraft is only about 150 times as fast as the speed of a brisk walk. The orbital speed of our astronauts, circling the globe in about ninety minutes at an altitude of a hundred miles, is only slightly more than 4,000 times as fast as the speed of walking. If one thinks of
instances of the numerical gain achieved by technology since 1894, the case of transport speed is a mild instance.
A modern electronic computer, which in one minute can carry out as much arithmetic computation as a skilled human computer can achieve in a lifetime, furnishes an instance of speed-up by a factor of almost forty million. It there had occurred an equal speed-up in transport, a flight today from New York to London would take less than one thousandth of a second! An instance of an increase that is even greater than the speed-up in computing is furnished by the fact that an atom of coal can furnish two or three electron volts of energy, whereas an atom of uranium 235 yields in fission 200 million electron volts.
The cited numerical increases in speed of transport, in speed of computing, in available energy are impressive. In fact, they are more significant than is indicated by the numerical factors. For when technology increases the speed of any process or the amount of any quantity-for instance, a quantity of available energy—by, say, 10 or 20 per cent, this quantitative change can be useful and important. But when a quantity is increased by a very large factor—say, a billion —then a surprising thing often happens. Indeed, a large enough change in quantity often results in a change in quality. For example, if through developments in nuclear physics man has available to his purposes billions of times as much energy as he had before, it does not suffice merely to say that he has a lot more energy. He has, in fact, something quite other than what he had before. He now has so much energy that he can realistically think of attacking problems that were previously totally insuperable. For example, he might now think of desalting enough sea water
to make deserts bloom; or of changing climate by melting the polar ice caps or by altering ocean currents.
Speed of computing is a good technological illustration of the magic shift from quantity to quality. When the speed of computation is stepped up by a factor of 10', then it is no longer sufficient to say "This new device is notably more rapid than its predecessors." For that much gain in speed proves to be more than just gain in speed. The new device not only does all previous computing tasks much faster; it also opens up previously inaccessible possibilities.
Suppose, for instance, that astronomers have an excellent and complete theory for the motion of, say, the moon. But suppose that this theory is so complicated that the computation of the path of the moon over a period of a month requires perhaps two months. Then predictions of future positions cannot be computed out rapidly enough to be useful. You can't compute, so to speak, as fast as the moon moves, so you cannot usefully predict the moon's future positions. This, incidentally, is not a fanciful example but an actual one.
Another example is the computation of the aerodynamic and thermodynamic equations which describe the motion of our atmosphere. These computations are so complex and extensive that long-range weather forecasting would be completely unthinkable if one were limited to the type of computing that was possible before the electronic computer. It would be wholly unfair to the new device merely to say that it does these computations faster than they could be done before. The gain that results from the new device is not just a quantitative gain, it is a qualitative gain. The modern electronic computer, in fact, makes
possible a quantitative attack on many kinds of problems that previously were prohibitively complex. It is, indeed, almost impossible to imagine, in advance, the usefulness of such a device. In today's mail, as I write this, I find an invitation to attend a summer conference under impeccably competent and serious auspices, to be devoted to a consideration of "Computers and Religion." Who, twenty-five years ago (to say nothing of seventy-five years ago) would have taken seriously such a title!
To turn, now, to the record of the second most frequently cited item of contrast between the present day and the past, it is surely true that the last years have seen a spectacular advance in communication. As for the telephone, radio, and television, the improvement is in my case measured from zero, for in my childhood we had no telephone, and we did not dream of radio or television. All three modes of communication have, in fact, enormously improved in the last quarter century, not to mention the last three quarters. The present direct phone dialing across our continent and the quality of transmission are almost miracles of scientific ingenuity and engineering skill. And when, in the living room of a house in Connecticut, one can observe in color, via satellite, events as they are taking place in Europe, he should, at least once in a while, stop to contemplate the amount of scientific and engineering genius that has been applied to the design and construction of all the instrumentation involved, not forgetting the reliability of the unattended receiving and transmitting equipment in the satellite, nor the recently acquired skill which permits placing the satellite accurately in an orbit that leaves it in a position fixed relatively to the revolving earth. The sensitivity of the modern receiving equipment is well
indicated by the fact that a dependable signal can be sent to the earth from equipment on the surface of the moon, using less than 10 watts of power. This is so small and weak a power source that it is unlikely that the reader has in his house an electric globe of as little as 10 watts. That is the size that is traditionally used in the back hall of an Italian pensione, but hardly anywhere else.
The great improvements in transport and communication touch all of us; but they do not affect our modern lives as frequently as do many other products of today's technology. To sense the ubiquity and the immediacy of the aids to the mechanics of living that serve us today and that were not available during my youth, just look about you the dishwasher, the refrigerator, the freezer, both of the by every supermarket-all of these are comparatively recent. The kitchen in my own home, and it is by no means extraordinary in its equipment, profits from the silent and ever available service of nearly a dozen electric motors. It testimony to the way technology now serves us to note, on one wall, an electric can opener! But that this device is a in your house. Especially in the kitchen! The modern stove, latter containing examples of the pre-prepared foods carried seems a trivial and, in a sense, almost ridiculous item of welcome aid in the modern home is evidenced by the fact that Macy's now carries twenty-two models of electric can openers.
Near the beginning of this book I spoke of the kitchen in the small house of my Grandmother Weaver. It did not have any cupboards or cabinets, for in those days everyone had a pantry. In addition to the wood-burning range the only other piece of equipment that I recall was a handoperated, or better, an arm-operated water pump. It did,
however, have one other very important piece of equipment, and that was a large and generously supplied cookie jar, always available to small boys.
Two modern devices in the kitchen and service end of the house have a special flavor for me, in terms of the contrast with my youth. One morning each week, in my earliest teens, I got up early so as to have time, before school, to turn the wringer for my mother, as she did the weekly wash. And on Saturday morning, I remember, as I glance at the vacuum cleaner in the closet, it was my regular duty to take the smaller rugs out to the back yard and beat the dust out of them.
I had another household task that serves to highlight the difference between then and now. In my present home, newspapers are saved for starting fires in our living-room fireplace. In the home of my youth they were saved for me to use them, crumpled up, to clean out the major accumulation of soot in the glass chimneys of our kerosene lamps. Now, one of our electric clocks turns on the lights in our living room at dusk, and turns them out after we have gone to bed.
Yes, science and technology now touch us every hour of every day, as they certainly did not in the 1890s. Chelsea House has just issued a facsimile reproduction of the 1897 Sears Roebuck catalogue. From this, a vivid and fascinating picture of the contrast, between 1897 and now, in household equipment and conveniences can be quickly gained. The section on household utensils contains many models of wood or coal stoves, galvanized washtubs, coal scuttles, and mop wringers, but not a single electrically operated device. For the entertainment of the family there were musical instruments, books, magic lanterns, and stereopticons with slides of Uncle Tom being sold and leaving his family, of Yellowstone Park, and of Bible scenes.
To move up several levels of significance from the trivial one of gadgetry, a major contrast between now and my earliest days is to be found in the progress—here very closely correlated with the advances of scientific knowledge in the biological and related sciences—in the prevention, control, and cure of diseases.
A person born in the United States in 1900 had a life expectancy of about forty-six years. At the present time, this figure has been increased, by medical science, to 66.8 for males and 73.7 for females. In 1900 the age-adjusted death rate, from all causes, was 1,778.5 per 100,000 population. Today this has been spectacularly reduced to 741.8. In the case of some of the dread childhood diseases of 1900, the gain to the present has been spectacular. For measles during the first four years of life, the death rate figure in 1900 was 87.6; today it is 0.4. The same figures for whooping cough have been reduced from 60.2 to 0.1. Diphtheria was a dangerous childhood disease in 1900, the death rate for children during their first four years being 271.0 per 100,000.
The present figure is so near zero that it is seldom recorded.
The record of the last few decades in the almost complete conquering of the infectious diseases is a bright and important item in the health contrast between then and now. The very recent conquest of polio also deserves a glittering citation, and it is hard to suppress the optimistic conviction that we are now on the threshold of great gains with respect to heart disease and cancer.
These advances have required the most dedicated service of some of our most gifted scientists. The pace of this advance has been rapid in the more recent years. A great many of the important drugs carried by a drug store today were unknown and undreamed of even a quarter of a century ago. Imagine the bewilderment of my father if he could step out of his small drug store of 1894 into the prescription department of his modern successor.
I stated earlier my conviction that I was born at the right time. Indeed, I would claim that I picked almost precisely the right time. All of us today are conscious that we are living in the electronic age. In 1897, when I was only three years old, the British physicist Sir Joseph John Thomson (1856-1940), noting that cathode rays could be deflected by a magnetic field, discovered the electron and initiated our present era. When I was one year old, the German physicist Wilhelm Konrad Roentgen (1845-1925) discovered X rays, which were to prove indispensable to medicine and surgery as well as a fine tool for exploring the structure of matter. With these two central discoveries, there began what is surely the richest, the most exciting period the physical sciences have ever experienced.
In spite of the great advances during the seventy-four-year interval from 1894 to 1968 in biology, medicine, and other fields of science, I think the most striking and most profound change has occurred in physics. It would be incorrect to give the impression that the contrast arises because nineteenth-century physics was a slowly or weakly developing subject. Although the foundations had been laid earlier for the whole great field of dynamics, the nineteenth century saw the emergence of much of our modern large-scale knowledge of electricity, magnetism, and electro-
dynamics. Giving a good practical knowledge of the action of large-scale electrical forces, these developments made possible the industrial revolution which replaced steam power by electrical power, and which initiated, late in the century, the myriad uses of electric motors and the marvels of electric lighting, of telephony, and of wireless telegraphy.
Once the electron had been discovered, the attack on the secrets of atomic structure was dramatically rapid and successful. In 1913 there was published the first of a series of truly epoch-making papers on atomic structure by Niels Bohr. The first transmutation of one element into another —nitrogen to oxygen—was accomplished in 1919 by the British physicist Sir Ernest Rutherford (1871-1937).
The amazing minds of the ancient philosophers and poets speculated about the ultimate constitution of matter, but they had only imagination and analogy as tools. The opening-up of the atomic world, subsequently extended into the still smaller nuclear world, is one of the greatest of man's triumphs, and this exploration effectively began just before the turn of the century.
This, however, is only a small part of the story, for there have been two other developments in physics during my lifetime, even more original, more profound, and more far-reaching in their implications. These, of course, are relativity theory and quantum theory. The former was begun in Einstein's restricted theory of 1905, and magnificently extended in the general theory which appeared in 1916. The second was quantum theory, which originated as something startlingly new and indeed even bizarre, with ideas that the German physicist Max Planck (1858-1947) announced in 1900. Planck affirmed that energy was not a
smoothly and continuously divisible entity, capable of existing in any amount, but rather that energy existed in discrete, indivisible bits. The validity of this powerful and strange new concept was confirmed by theoretical work on the photoelectric effect which Einstein published in 1905 and was later experimentally confirmed by Millikan.
Relativity and quantum theory opened up wholly new regions of physics, truly undreamed of when I was born; and each of these had tremendous philosophical consequences as well. The complete collapse of any idea of the absolute measurement of time, the blending of space and time into a four-dimensional complex, the destruction of the physical concept of continuity, the puzzling but inescapable fact that an electron is both a particle and a wave and the resulting concept of complementarity, the shattering of determinacy in the world of ultimate particles (explained in Chapter 10); the release of nuclear energy—these were scientific episodes of a majestically new power and sweep.
The advance of physics during my lifetime has involved the elaboration of theories which, with almost unbelievable precision, deal with an ever greater array of physical phenomena, not only at molecular and atomic dimensions, but also even at nuclear dimensions. In the advance of solid-state physics (the theories concerning the detailed behavior of the electric entities which form solid pieces of matter—for instance, pieces of metal or crystalline substances) one of the recent dramatic episodes has been the design and construction, even on regular commercial schedules, of solid-state microelectronic devices. These reduce entire electronic circuits, previously filling the whole
interior of a good-sized radio, to such tiny dimensions that a square silicon chip less than one one-hundredth of an inch thick and about one tenth of an inch on a side can, by a complicated and delicate manufacturing procedure, be made equivalent to 100 to 500 integrated circuits, each containing 10 to 20 transistors and, say, 50 resistors. These minuscule devices require, moreover, very little energy and generate very little heat. They are so rugged and dependable that they can be used in solid-fuel missiles. The matchbox radios that football fans take to the stadium so that they can also overhear other games have seemed to us marvels of compact skill. But the new micro-micro techniques can reduce the circuitry of a large section of an electronic computer to the volume dimensions of a thimble.
The record of physics, especially from about 1920 to today, is a dazzling one indeed, penetrating ever deeper and deeper into the behavior of matter, and furnishing dependable guides for the construction and use of ever more complicated devices.
As an intellectual tour de force, the world has probably never before seen anything like this. The complexity and precision of the theories demand and merit the greatest admiration.
Closely associated with the explosive growth of physics
In 1894, astronomers were pretty sure that the Milky Way was a star system some 10,000 to 20,000 light-years in diameter, and there was no certainty that there was anything farther out. The distance determinations of that time
depended upon parallax measurements, and these became ineffective at distances of about 100 light-years, so that larger figures were based on speculation only. Nowadays the boundaries extend to something like ten billion light-years, the extreme evidence being subject to uncertainties in the application of relativity theory to objects whose red shift is large.
In 1894 nuclear energy was unthought of, and astronomers believed that the sun derived its energy from gravitational attraction. On that basis, the age of the sun was then estimated to be something like fifteen million years, whereas today we believe the age of the sun to be about six billion years.
In addition to continuous and steady progress in all aspects of astronomical knowledge, there have emerged, especially over the last decade or so, a number of exciting new types of problems which now confront the astronomer. There have been located in the sky extremely powerful sources of radio energy, especially in the very short X-ray wave-length regions; these are often, if not usually, unassociated with any optically visual celestial object. The nature of these sources and their possible relation to the birth or death of stars present a whole array of puzzling and fascinating problems. Very recently, moreover, signals have been received from well-defined and angularly small regions of the sky, these signals being wholly extraordinary in that they are periodic in character, the intervals between successive signals being strangely precise. These have inevitably caused curiosity as to whether some advanced sentient forms of life may exist elsewhere and may be trying to communicate with us. All this is as yet wholly speculative.
in nature, but hints at how much astronomy still has to learn.
It is certainly incorrect to say that the twentieth century has seen the disappearance of chemistry as a discipline in its own right, but nevertheless a great deal of the most fundamental, and most of the purely theoretical, chemistry has now become indistinguishable from physics. Indeed, two of the men who have had the greatest influence on the development of chemistry in this century, the Dutch-American physical chemist Peter Pieter Debye (1884-1966) and Linus Pauling, have used techniques and ideas that came chiefly from physics; Debye, in fact, was often, if not usually, classified as a physicist.
Some of the most outstanding accomplishments of modern chemistry lie in the field of organic synthesis—the production by the chemist, often starting with materials which are totally inorganic in nature, of substances which imitate, and which often improve upon, those previously produced by nature. One thinks at once of all the artificial fibers that make possible wrinkleproof and stainproof cloth, of the plastics that have become such familiar servants of our everyday needs, of the synthetic rubber out of which, along with imbedded bands of nylon or other synthetic fabric, longer-wearing and safer tires can be made. A number of the most complicated natural products which are used by the physicians, such as quinine, morphine, and insulin, have by now been produced in the laboratory. The 1930s saw the synthesis of a number of the vitamins—a vitamin was defined by the German-American biochemist Rudolph
Schoenheimer (1898-1941) as "something that makes you sick if you don't eat it."* However, the syntheses of these biologically important substances, having from twenty to seventy atoms per molecule, were overshadowed by more complicated and difficult triumphs which principally began in the 1940s.
In many instances the chemist is now able to decide what properties his new material could most usefully have, and can then fabricate to these specifications, often outdoing nature. The magnitude and the practical economic importance of the work of the chemists are indicated by the fact that a recent study found that the chemical industry is directly responsible for $27 billion a year of our gross national product, and that this scientific technical industry provides the materials that are indispensable for other industries which account for $67 billion of our gross national product. The record of the creation of improved new synthetic fibers by chemistry is clearly not a closed story. A recent newspaper article reported that the Du Pont company had just displayed clothing made from a new silklike fiber on whose creation the company has spent more than $75 million over a twenty-year period. In luster, color clarity, dyeability, and draping characteristics the cloth woven from this new synthetic material is said to be equivalent to the most luxurious silk fabrics.
A large part of the spectacular advance of the biological sciences in the twentieth century has centered around the
* Knowledge of the deficiency diseases began with the diagnosis of beri-beri in 1897 by the Dutch bacteriologist Christian Eijkman (18581930).
rise in genetics which started in 1900. In fact, practically all the other great advances in biology either stem from that or are related to it.
The pioneer work of the Austrian biologist Gregor Mendel (1822-1884) in discovering the basic laws of inheritance was a nineteenth-century achievement, his important results having been published in an obscure journal in 1866. But it was not until 1900 that this work was rediscovered practically simultaneously by three botanists: the Dutch Hugo De Vries (1848-1935), the German Karl Erich Correns (1864-1933), and the Austrian Erich Tschermak von Seysenegg (1836-1937). Great credit is due to Mendel, but it is by no means correct that the rise which began in 1900 was really due to him; indeed some of the motivation of the American zoologist Thomas Hunt Morgan (1866-1945) resulted from his temporary conviction that Mendel had at least in part gone wrong, so that it was important critically to check his work. Edmund Beecher Wilson (1856-1939), also an American, had published The Cell in Development and Inheritance, and by that time the groundwork had already been laid for the great advances in cytology and genetics that followed.
What has happened since then is more than a volume could recount. Genetics, which started at the level of the single organism, has moved down to the molecular level and up to the population level. Evolution has been revitalized, and has become an essentially new, powerful, synthesizing theory. The whole spectacular field of molecular biology has burst on us. Indeed the major scientific concept of the century is that coding of biological information occurs in giant molecular polymers of which one, DNA (deoxyribose nucleic acid), is capable of storing the genetic information and is also capable of self-replication so that the genetic information may be passed on from generation to generation.
The determination of the detailed double-spiral structure of DNA in 1953 was doubtless one of the greatest triumphs that science has ever achieved. To crown this, recent work has almost completely explained the detailed way in which triplets of nucleotides in the DNA molecule control the biochemical activities which lead to the synthesis of the proteins which the genetic material—the DNA— specifies.
These results are so far-reaching that there are those who consider that molecular biology now has left before it, as a challenge to its future, only the mopping-up of a few details of the genetic process.
Others, and I am confident that they are correct, see molecular biology moving on to even greater triumphs. There seems every reasonable prospect that we will, before long, understand immunological reactions at a detailed and in fact molecular level. We must also discover, and doubtless we will, the ways in which differentiation occurs—the detailed controls that provide that certain cells become liver cells whereas others acquire the characteristics that enable them to form other parts of the body.
One of the most exciting prospects for molecular biology is that it will in the next decades give us some real understanding of the functioning of the central nervous system—how do we learn, how do we remember, why do we forget?
Indeed it seems to many scientists, and perhaps to most molecular biologists, that any well-posed question about a living organism can be, and eventually will be, answered in the language of physics and chemistry.
The dramatic period for the physical sciences almost surely was the first few decades of the present century. It seems probable that the equally dramatic period for the biological sciences will be the next few decades. To come back to the theme of my good luck in timing, I had a chance to observe all of the former period, and I am now having the exhilarating chance to observe at least the opening stages of the second period. I have also had the good luck to live through the most vigorous period that science has ever had. The great forward surge of science during my lifetime is highlighted by the estimate that of all the scientists who have ever lived, some 95 per cent are alive today. That the surge continues at an ever-increasing pace is further emphasized by the estimate that of all the words ever written on scientific topics, some 15 per cent were written in the year 1967.