J. Robert Oppenheimer: Along with Albert Einstein, one of the most interesting and important figures in modern history. Although very different in world-view and personality, the names of these two men are both linked to arguably the most significant human endeavor and resultant “success” in recorded history. The effort in question was the monumental task of the United States government to harness the energy of the atom in a new and devastating weapon of war, the atomic bomb. The super-secret Manhattan Project was a crash program formally authorized by president Franklin Roosevelt on Dec. 6, 1941. The program’s goal: In a time-frame of less than four years and against all odds, to capitalize on very recent scientific discoveries and rapidly develop an operational military weapon of staggering destructive power.
Albert Einstein and the Atomic Bomb
Albert Einstein, whose scientific resume ranks just behind that of Isaac Newton, had virtually no role in this weapons program save for two notable exceptions. First and foremost, it was Einstein’s follow-up paper to his milestone theory of special relativity in 1905 which showed that, contrary to long-standing belief, mass and energy are one and the same, theoretically convertible from one to another. That relationship is expressed by the most famous equation in science, e = mc2, where e is the energy inherent in mass, m is the mass in question, and c is the constant speed of light. One careful look at this relationship reveals its profoundness. Since the speed of light is a very large number (300 million meters per second), a tiny bit of mass (material) converted into its energy equivalent yields a phenomenal amount of energy. Note that Einstein had proposed a theoretical, nonetheless real, relationship in his equation. The big question: Would it ever be possible to produce that predicted yield of energy in practice? In 1938, two chemists in Hitler’s Germany, Hahn and Strassman, demonstrated nuclear fission in the laboratory, on a tiny scale. That news spread quickly throughout the world physics community – like ripples on a giant pond. It now appeared feasible to harness the nuclear power inherent in the atom as expressed by Einstein’s equation.
In August of 1939, alarmed by the recent news from Germany, Hungarian physicist Leo Szilard asked his colleague, Albert Einstein, to affix his signature to a letter addressed to President Roosevelt. The letter warned of recent German scientific advances and Germany’s sudden interest in uranium deposits in the Belgian Congo of Africa. Einstein, a German Jew who fled his homeland in 1932 for fear of Hitler’s growing influence, dutifully but reluctantly signed his name to the letter. Einstein’s imprimatur on the letter was Szilard’s best hope of affixing Roosevelt’s attention on the growing feasibility of an atomic bomb. Einstein and many other European scientists were, from personal experience, justifiably terrified at the prospect of Hitler’s Germany acquiring such a weapon, and the Germans had first-class scientific talent available to tackle such a challenge.
Einstein, one of history’s great pacifists, was thus ironically tied to the atomic bomb program, but his involvement went no further. Einstein never worked on the project and, after the war when Germany was shown to have made no real progress toward a weapon, he stated: “Had I known that the Germans would not succeed in producing an atomic bomb, I never would have lifted a finger.”
Stranger Than Fiction: The High Desert of Los Alamos, New Mexico
By early 1943, peculiar “invitations” from Washington were being received by many of this country’s finest scientific/engineering minds. A significant number of these ranked among the world’s top physicists including Nobel Prize winners who had emigrated from Europe. These shadowy “requests” from the government called for the best and the brightest to head (with their families in many cases) to the wide-open high desert country of New Mexico. Upon arrival, they would be further informed (to a limited extent) of the very important, secret work to be undertaken there. I have always believed that fact is stranger than fiction, and much more interesting and applicable. What transpired at Los Alamos over the next three years under the direction of J. Robert Oppenheimer and Army General Leslie Groves is scarcely believable, and yet it truly happened, and it has changed our lives unalterably.
One of my favorite narratives from Jon Else’s wonderful documentary film on the atomic bomb, The Day After Trinity, beautifully describes the ludicrous situation: “Oppenheimer had brought scientists and their families fresh from distinguished campuses all over the country – ivied halls, soaring campaniles, vaulted chapels. Los Alamos was a boom town – hastily constructed wooden buildings, dirt streets, coal stoves, and [at one point] only five bathtubs / There were no sidewalks. The streets were all dirt. The water situation was always bad / It was not at all unusual to open your faucet and have worms come out.” Los Alamos was like a California gold-rush boom town, constructed in a jiffy with the greatest assemblage of world-class scientific talent that will ever be gathered in one location. General Groves once irreverently quipped (with humor and perhaps some frustration) that Los Alamos had the greatest assemblage of “crack-pots” the world has ever known.
As improbable as the situation and the task at hand appeared – even given an open check-book from Roosevelt and Congress – Groves and Oppenheimer made it happen. I cannot think of any human endeavor in history so complex, so unlikely…and so “successful.” The triumph of NASA in space comes in a close second, but even realizing JFK’s promise of a man on the moon by 1969 cannot top the extraordinary scenario which unfolded at Los Alamos, New Mexico – all largely shielded from view.
The initial (and only) test of the atomic bomb took place on July 16, 1945, on the wide expanse of the New Mexico desert near Los Alamos. The test was code-named “Trinity.” The accompanying picture shows Oppenheimer and General Groves at ground zero of the blast, the site of the high tower from which the bomb was detonated. Evidence of desert sand fused into glass by the intense heat abounds. The test was a complete technical success – vindication for the huge government outlay and the dedication on the part of so many who put their lives on hold by moving to the high desert of New Mexico and literally “willing” their work to success for fear of the Germans. By July of 1945, however, Germany was vanquished without having made any real progress toward an atomic bomb.
The World Would Never Be the Same
That first nuclear detonation signaled a necessary reset for much of human thought and behavior. Many events quickly followed that demonstrated the power of that statement. Of immediate impact was the abrupt termination of World War II, brought about by two atomic bombs successfully dropped on Japan just weeks after the first and only test of the device (Hiroshima, August 6, 1945; Nagasaki, August 9, 1945). The resulting destruction of these two cities accomplished what many thousands of invading U.S. troops might have taken months to complete – with terrible losses. The horrific effect of these two bombs on the people of Japan has been well documented since 1945. Many, including a significant number of those who worked on the development of these weapons protested that such weapons should never be used again. Once the initial flush of “success” passed, the man most responsible for converting scientific theory into a practical weapon of mass destruction quickly realized that the “nuclear genie” was irretrievably out of the bottle, never to be predictably and reliably restrained. Indeed, Russia shocked the world by detonating its first atomic bomb in 1949. The inevitable arms race that Oppenheimer foresaw had already begun… the day after Trinity.
The Matter of J. Robert Oppenheimer, the Man
J. Robert Oppenheimer had been under tremendous pressure as technical leader of the super-secret Manhattan project since being appointed by the military man in charge of the entire project, Army general Leslie Groves. Groves was a military man through and through, accustomed to the disciplined hierarchy of the service, yet he hand-picked as technical lead for the whole program the brilliant physicist and mercurial liberal intellectual, J. Robert Oppenheimer – the most unlikely of candidates. Oppenheimer’s communist wife and brother prompted the FBI to vigorously protest the choice. Groves got his way, however.
Groves’ choice of J. Robert Oppenheimer for the challenging and consuming task of technical leader on the project proved to be a stroke of genius on his part; virtually everyone who worked on the Manhattan Project agreed there was no-one but Oppenheimer who could have made it happen as it did.
“Oppie,” as he was known and referred to by many on the Manhattan Project, directed the efforts of hundreds of the finest scientific and engineering minds on the planet. Foreign-born Nobel prize winners in physics were very much in evidence at Los Alamos. Despite the formidable scientific credentials of such luminaries as Hans Bethe, I.I. Rabi, Edward Teller, Enrico Fermi, and Freeman Dyson, Oppenheimer proved to be their intellectual equal. Oppenheimer either already knew and understood the nuclear physics, the chemistry, and the metallurgy involved at Los Alamos, or he very quickly learned it from the others. His intellect was lightning-quick and very deep. His interests extended well beyond physics as evidenced by his great interest in French metaphysical poetry and his multi-lingual capability. Almost more incredible than his technical grasp of all the work underway at Los Alamos was his unanticipated ability to manage all aspects of this, the most daring, ambitious, and important scientific/engineering endeavor ever undertaken. People who knew well his scientific brilliance from earlier years were amazed at the overnight evolution of “Oppie, the brilliant physicist and academic” into “Oppie, the effective, efficient manager” and co-leader of the project with General Groves.
Indelibly imprinted upon my mind is the interview scene with famous Nobel Laureate Hans Bethe conducted by Jon Else, producer of The Day After Trinity. Bethe was Oppie’s pick to be group leader for all physics on the project. The following comments of Bethe, himself a giant in theoretical physics, cast a penetrating light on the intellectual brilliance of J. Robert Oppenheimer and his successful role in this, the most daring and difficult scientific project ever attempted:
– “He was a tremendous intellect. I don’t believe I have known another person who was quite so quick in comprehending both scientific and general knowledge.”
– “He knew and understood everything that went on in the laboratory, whether it was chemistry, theoretical physics, or machine-shop. He could keep it all in his head and coordinate it. It was clear also at Los Alamos, that he was intellectually superior to us.”
The work was long, hard, and often late into the night at Los Alamos for its two thousand residents, but there was a social life at Los Alamos, and, according to reports, Robert Oppenheimer was invariably the center of attention. He could and often did lead discussions given his wide-ranging knowledge …on most everything! Dorothy McKibben (seated on Oppenheimer’s right in the following picture) was the “Gatekeeper of Los Alamos” according to all who (necessarily) passed through her tiny Manhattan Project Office at 109 East Palace Avenue, Santa Fe, New Mexico. There, they checked-in and collected the credentials and maps required to reach the highly secured desert site of Los Alamos. Ms. McKibben was affluent in her praise of Oppenheimer: “If you were in a large hall, and you saw several groups of people, the largest groups would be hovering around Oppenheimer. He was great at a party, and women simply loved him and still do.”
The Nuclear Weapons Advantage Proves to be Short-Lived
What was believed in 1945 to represent a long term, decided military advantage for the United States turned out to be an illusion, much as Oppenheimer likely suspected. With the help of spies Klaus Fuchs at Los Alamos, Julius Rosenberg, and others, Russia detonated their first atomic bomb only four years later.
Oppenheimer knew better, because he understood the physics involved and that, once demonstrated, nuclear weapons would rapidly pose a problem for the world community. When interviewed years later at Princeton where he had been head of the Institute for Advanced Studies (and Albert Einstein’s “boss”) he is shown in The Day After Trinity responding to the question, “[Can you tell us] what your thoughts are about the proposal of Senator Robert Kennedy that President Johnson initiate talks with the view to halt the spread of nuclear weapons?” Oppenheimer replied rather impatiently, “It’s twenty years too late. It should have been done the day after Trinity.”
J. Robert Oppenheimer fully appreciated, on July 16, 1945, the dangers inherent in the nuclear genie let loose from the bottle. His fears were well founded. Within a few years after Los Alamos, talk surfaced of a new, more powerful bomb based on nuclear fusion rather than fission, nevertheless still in accordance with e = mc2. This became popularly known as the “hydrogen bomb.” Physicist Edward Teller now stepped forward to promote its development in opposition to Oppenheimer’s stated wish to curtail the further use and development of nuclear weapons.
Arguments raged over the “Super” bomb as it was designated, and Teller prevailed. The first device was detonated by the U.S. in 1952. A complex and toxic cocktail of Oppenheimer’s reticence toward development of the Super combined with the past communist leanings of his wife, brother Frank, and other friends led to the Atomic Energy Commission, under President Eisenhower, revoking Oppenheimer’s security clearance in 1954. That action ended any opportunity for Oppenheimer to even continue advising Washington on nuclear weapons policy. The Oppenheimer file was thick, and the ultimate security hearings were dramatic and difficult for all involved. As for the effect on J. Robert Oppenheimer, we have the observations of Hans Bethe and I.I. Rabi, both participants at Los Alamos and Nobel prize winners in physics:
– I.I. Rabi: “I think to a certain extent it actually almost killed him, spiritually, yes. It achieved just what his opponents wanted to achieve. It destroyed him.”
– Hans Bethe: “He had very much the feeling that he was giving the best to the United States in the years during the war and after the war. In my opinion, he did. But others did not agree. And in 1954, he was hauled before a tribunal and accused of being a security risk – a risk to the United States. A risk to betray secrets.”
Later, in 1964, attitudes softened and Edward Teller nominated Oppenheimer for the prestigious Enrico Fermi award which was presented by President Johnson. As I.I. Rabi observed, however, the preceding events had, for all intents and purposes, already destroyed him. Oppenheimer was a conflicted man with a brilliant wide-ranging intellect. While one might readily agree with Hans Bethe’s assessment that Oppenheimer felt he was “giving the best to the United States in the years during and after the war,” there is perhaps more to the story than a significantly patriotic motivation. Oppenheimer was a supremely competent and confident individual whose impatient nature was tinged with a palpable arrogance. These characteristics often worked to his disadvantage with adversaries and co-workers.
Then there was the suggestion that, in addition to his patriotic motives, Oppenheimer was seized by “the glitter and the power of nuclear weapons” and the unprecedented opportunity to do physics on a grand scale at Los Alamos, and those were also major motivations. Other colleagues on the project later confessed to feeling the glitter and power of nuclear weapons, themselves. A brilliant man of many contradictions was Oppenheimer – that much is certain. Also certain is the likelihood that the man was haunted afterward by misgivings concerning his pivotal role, whatever his motivations, in letting loose the nuclear genie. The sadness in his eyes late in life practically confirms the suspicion. That is the tragedy of J. Robert Oppenheimer. Triumph has a way of extracting its penalty, its pound of flesh. I can think of no better example than Oppenheimer.
Immediately upon hearing of the bombing of Hiroshima, Hans Bethe recalled, “The first reaction which we had was one of fulfillment. Now it has been done. Now the work which we have been engaged in has contributed to the war. The second reaction, of course, was one of shock and horror. What have we done? What have we done? And the third reaction: It shouldn’t be done again.”
Nuclear Weapons: The Current State and Future Outlook
In the headlines of today’s news broadcasts as I write this is the looming threat of North Korean nuclear-tipped intercontinental ballistic missiles. The North Koreans have developed and tested nuclear warheads and are currently test-launching long-range missiles which could reach the U.S. mainland, as far east as Chicago. Likewise, Iran is close to having both nuclear weapons and targetable intermediate-range missiles. Nuclear proliferation is alive and well on this earth.
To illustrate the present situation, consider one staple of the U.S. nuclear arsenal -the one megaton thermonuclear, or hydrogen, bomb with the explosive equivalent of just over one million tons of TNT. That explosive energy is fifty times that of the plutonium fission bomb which destroyed the city of Nagasaki, Japan (twenty-two thousand tons of TNT). The number of such powerful weapons in today’s U.S. and Russian nuclear stockpiles is truly staggering, especially when one considers that a single one megaton weapon could essentially flatten and incinerate the core of Manhattan, New York. Such a threat is no longer limited to a device dropped from an aircraft. Nuclear-tipped ICBMs present an even more ominous threat.
The surprise success of the first Russian earth-orbiting satellite, “Sputnik,” in 1957 had far more significance than the loss of prestige in space for the United States. Accordingly, the second monumental and historic U.S. government program – on the very heels of the Manhattan Project – was heralded by the creation of NASA in 1958 and its role in the race to the moon. President John F. Kennedy issued his audacious challenge in 1963 for NASA to regain lost technical ground in rocketry by being first to put a man on the moon …in the decade of the sixties – in less than seven years! Many in the technical community thought the challenge was simply “nuts” given the state of U.S. rocket technology in 1963. As with the then very-recent, incredibly difficult and urgent program to build an atomic bomb, the nation once again accomplished the near-impossible by landing Armstrong and Aldrin on the moon on July 20, 1969 – well ahead of the Russians. And it was important that we surpassed Russia in rocket technology, for our ICBMs, which are the key delivery vehicle for nuclear weapons and thus crucial to most of the U.S. strategic defense, were born of this country’s efforts in space.
“Fat Man,” the bomb used on Nagasaki – 22 kilotons of TNT
Photo: Paul Shambroom
B83 1 megaton hydrogen bombs…compact and deadly
The above picture of a man casually sweeping the warehouse floor in front of nearly ten megatons of explosive, destructive power, enough to level the ten largest cities in America gives one pause to reflect. On our visit to Los Alamos in 2003, I recall the uneasy emotions I felt merely standing next to a dummy casing of this bomb in the visitor’s center and reflecting on the awesome power of the “live” device. Minus their huge development and high “delivery” costs, such bombs are, in fact, very “cheap” weapons from a military point of view.
One conclusion: Unlike the man with the broom in the above picture, we must never casually accept the presence of these weapons in our midst. One mistake, one miscalculation, and nuclear Armageddon may be upon us. The collective angels of man’s better nature had better soon decide on a way to render such weapons unnecessary on this planet. Albert Einstein expressed the situation elegantly and succinctly:
“The unleashing of [the] power of the atom has changed everything but our modes of thinking and thus we drift toward unparalleled catastrophes.”
Under a brilliant New Mexico sky on October 16, 1945, the residents of the Los Alamos mesa gathered for a ceremony on J. Robert Oppenheimer’s last day as director of the laboratory. The occasion: The receipt of a certificate of appreciation from the Secretary of War honoring the contributions of Oppenheimer and Los Alamos.
In his remarks, Oppenheimer stated: “It is our hope that in years to come we may look at this scroll, and all that it signifies, with pride. Today, that pride must be tempered with a profound concern. If atomic bombs are to be added as new weapons to the arsenals of a warring world, or to the arsenals of nations preparing for war, then the time will come when mankind will curse the names of Los Alamos and Hiroshima. The peoples of the world must unite, or they will perish.”
In today’s world, each step along the path of nuclear proliferation brings humanity ever closer to the ultimate fear shared by J. Robert Oppenheimer and Albert Einstein. The world had best heed their warnings.
I just bought a copy of his book, Facing the Big Cats, published in 1965. It is my second copy: I bought my first copy the year it appeared, and I still have it. My wife asked me, “Why do you need two copies of the same book?” My answer: “Because this second copy is in pristine condition and the book is an exemplary exposition of big cat behavior by a true American icon!” I was enthralled with the adventure, the copious photographs, and the taut, incisive text of the book back in 1965 and continue to be so today. I have a shelf of books on Africa and its wildlife, and this book fits in perfectly thanks to the big cat insight contained within its pages.
Beatty mentions many of his animals by name: Two of his favorite lions, Sultan (see picture) and Pharaoh are described in the book. Pharaoh is described as “…my most dependable lion. The biggest and most powerful animal in the act, he performs with spirit and never makes any trouble. More than any lion I have ever trained, he has curbed the fighting instinct. He gets into very few brawls [with other animals], but is a strict disciplinarian and when one of the other lions – perhaps a newcomer to the act – makes the mistake of advancing toward him with an angry growl and bared fangs, Pharaoh takes care of the situation by sending the offender spinning with a slap of his mighty paws. He has more natural dignity than any big cat I have ever handled. He comports himself with a kind of majesty that almost seems a reminder to the other animals that he expects them to be respectful in his presence. Pharaoh is seldom challenged. Among his co-performers are some pretty tough lions, but they don’t seem to want to tangle with him.”
Beatty recalled reading Martin Johnson’s famous book Lion and its description of a lion prior to a kill: “Its tail was slashing and its head dropped low.” Beatty added, “Well that describes Brutus perfectly before he upraised himself and pinned me against the bars. And that is why it had flashed across my mind that this was no longer the Brutus I knew, that this was a Brutus bent on killing.”
tscript: Thankfully today, respect for animals and their treatment has grown by leaps and bounds from attitudes prevalent within my early lifetime. I am certain that the proper treatment and preservation of big cats and other wildlife would be paramount in the minds of both J.A. Hunter and Clyde Beatty were they alive today to witness the dim prospects of these animals and their environments, victims of our modern, human-oriented world. It is undeniable that, while both men earned their livings long ago on the backs of some of nature’s most marvelous creatures, they nevertheless had great respect for the animals they dealt with. Times have changed. Let us hope that human society will properly adapt and protect and preserve these magnificent creatures, no matter what the cost and effort.
Is it not a comfort to find something in this life of constant and rapid change that bucks the tide? For me, it most certainly is – but why is that?
“I had a farm in Africa, at the foot of the Ngong Hills,” opens the richly written and highly acclaimed memoir, Out of Africa, by Karen Blixen (pen name: Isak Dinesen). In a curious chain of circumstances, my life-long fascination with Africa and its wildlife has recently been rekindled by her story and by other recent events. Many will recall the magnificent 1985 film, Out of Africa, which starred a young Meryl Streep and Robert Redford, directed by Sidney Pollack. The story’s setting recounts the sweeping panorama that was East Africa and Kenya in the early days of its capitol, Nairobi.
One of those who could and did meet Africa’s challenge was the Scotsman, John Alexander Hunter, who quickly became the most celebrated “white hunter” and later game warden in Africa’s history. Hunter arrived in Nairobi from Scotland in 1908 seeking adventure and a livelihood. Indeed, there was a need for “animal control” during the early days when native Africans eked out an existence among the then-teeming wildlife that surrounded them. Men like Hunter dealt with marauding elephants and rhinos that destroyed crops of the Masai and the Kikuyu farmers. And there were the occasional man-eaters, lions which had tasted human flesh and found the taking too easy. In the early days of plentiful game, white hunters paid their bills by guiding hunting safaris of the rich and privileged. Few people had the foresight in the 1920’s and 30’s to envision the dire wildlife situation which exists today in Africa. J.A. Hunter saw it coming as he later turned to work as a game warden and “gun safety” for strictly photographic safaris. It was J.A. Hunter’s iconic little book, Hunter, that first triggered my personal African odyssey more than fifty years ago. For that story as related on my earlier blog post about J.A. Hunter, click on the following link:
One of Nairobi’s early settlers not destined to make East Africa their permanent home was Karen Blixen who published Out of Africa in 1937, six years after returning to her native Denmark. Her memoir of the years 1913 to 1931 spent on her coffee farm high near the foot of the Ngong Hills, a dozen or so miles from Nairobi, creates a brilliant collage of Africa, Kenya’s bountiful wildlife, and the inscrutable native Africans who served her and her homestead. She related well to the Kikuyu and Somali Africans who worked her farm and household, even forming close bonds with several of those who served inside her home. Nonetheless, she appreciated her ultimate limits in that regard as she noted, “On our safaris and on the farm, my acquaintance with the Natives developed into a settled and personal relationship. We were good friends. I reconciled myself to the fact that while I should never quite know or understand them, they knew me through and through, and were conscious of the decisions I was going to take, before I was certain about them, myself.”
There is another prophetic book about Africa which, despite my early naivete concerning the subject, I was prescient enough to purchase in 1965, the year of its initial publication. Its title: The End of the Game, by Peter Beard. It has become something of a cult title, yet despite the author’s unorthodox style, the book was prophetic about the end of “the game” in Africa. While expressing grave pessimism over the fate of Africa’s game animals, the book’s larger thrust is a poke at “the game” as played in Nairobi and elsewhere by the early, privileged white “invaders” from colonial Britain and Europe as they went about executing new “land grants” and confiscating land from the resident natives to build their empires. Does that sound familiar to students of the American West and its history? The pages of this book contain many glimpses of the early settlers in and around Kenya including Baroness (Karen) Blixen and her lover and platonic ideal, the storied, Oxford educated white hunter, Denys Finch Hatton. Blixen and Finch Hatton came from aristocratic, wealthy backgrounds in Denmark and England, respectively. Like so many others of privilege who comprised the early colonial settlements in Kenya, they seemed by background unfit and unprepared to deal, long-term, with the demands of African existence. Blixen and her Danish nobleman husband at the time, Bror Blixen, made the ill-informed decision to plant coffee at their farm, ignoring the fact that the land was too elevated for favorable results. That fact and a later, devastating fire that destroyed the farm’s coffee processing barn, doomed Karen Blixen’s success in Africa.
H.K. “Pop” Binks came from Yorkshire and arrived in Nairobi in 1900, making him one of the town’s earliest white settlers. He lived very modestly in Nairobi with his wife “Binkie” until death claimed him in 1971. During his lifetime in Nairobi, Binks plied numerous trades, including local photographer, astronomer, and author. He exhibited the attitudes and adaptability that life in Africa demanded. I have read first-hand accounts concerning the initiative and resilience of Mr. Binks, and at least one educated voice who knew him personally claimed him to be “the most interesting person I ever knew.” In his book, African Rainbow, Binks stated: “I have been lonelier in the crowded streets of a city than in the great open spaces of Africa, with all wild things for companions.” 
In 1687, Newton’s Principia was published after three intense years of effort by the young, relatively unknown Cambridge professor of mathematics. Using mathematics and his revolutionary new concept of universal gravitation, Newton provided precise justification of Kepler’s laws of planetary motion in the Principia. In the process, he revolutionized motion physics and our understanding of how and why bodies of mass, big and small (planets, cannonballs, etc.), move the way they do. Newton did, indeed, as he stated, show us in the Principia how to calculate the motion of heavenly bodies.
