by Carl Sagan
In the exploration of Mars, unmanned vehicles have already soft-landed, and only a little further in the future they will roam about the surface of the Red Planet, as some now do on the Moon. We are not ready for a manned mission to Mars. Some of us are concerned about such missions because of the dangers of carrying terrestrial microbes to Mars, and Martian microbes, if they exist, to Earth, but also because of their enormous expense. The Viking landers deposited on Mars in the summer of 1976 have a very interesting array of sensors and scientific instruments, which are the extension of human senses to an alien environment.
The obvious post-Viking device for Martian exploration, one which takes advantage of the Viking technology, is a Viking Rover in which the equivalent of an entire Viking spacecraft, but with considerably improved science, is put on wheels or tractor treads and permitted to rove slowly over the Martian landscape. But now we come to a new problem, one that is never encountered in machine operation on the Earth’s surface. Although Mars is the second closest planet, it is so far from the Earth that the light travel time becomes significant. At a typical relative position of Mars and the Earth, the planet is 20 light-minutes away. Thus, if the spacecraft were confronted with a steep incline, it might send a message of inquiry back to Earth. Forty minutes later the response would arrive saying something like “For heaven’s sake, stand dead still.” But by then, of course, an unsophisticated machine would have tumbled into the gully. Consequently, any Martian Rover requires slope and roughness sensors. Fortunately, these are readily available and are even seen in some children’s toys. When confronted with a precipitous slope or large boulder, the spacecraft would either stop until receiving instructions from the Earth in response to its query (and televised picture of the terrain), or back off and start in another and safer direction.
Much more elaborate contingency decision networks can be built into the onboard computers of spacecraft of the 1980s. For more remote objectives, to be explored further in the future, we can imagine human controllers in orbit around the target planet, or on one of its moons. In the exploration of Jupiter, for example, I can imagine the operators on a small moon outside the fierce Jovian radiation belts, controlling with only a few seconds’ delay the responses of a spacecraft floating in the dense Jovian clouds.
Human beings on Earth can also be in such an interaction loop, if they are willing to spend some time on the enterprise. If every decision in Martian exploration must be fed through a human controller on Earth, the Rover can traverse only a few feet an hour. But the lifetimes of such Rovers are so long that a few feet an hour represents a perfectly respectable rate of progress. However, as we imagine expeditions into the farthest reaches of the solar system—and ultimately to the stars—it is clear that self-controlled machine intelligence will assume heavier burdens of responsibility.
In the development of such machines we find a kind of convergent evolution. Viking is, in a curious sense, like some great outsized, clumsily constructed insect. It is not yet ambulatory, and it is certainly incapable of self-reproduction. But it has an exoskeleton, it has a wide range of insectlike sensory organs, and it is about as intelligent as a dragonfly. But Viking has an advantage that insects do not: it can, on occasion, by inquiring of its controllers on Earth, assume the intelligence of a human being—the controllers are able to reprogram the Viking computer on the basis of decisions they make.
As the field of machine intelligence advances and as increasingly distant objects in the solar system become accessible to exploration, we will see the development of increasingly sophisticated onboard computers, slowly climbing the phylogenetic tree from insect intelligence to crocodile intelligence to squirrel intelligence and—in the not very remote future, I think—to dog intelligence. Any flight to the outer solar system must have a computer capable of determining whether it is working properly. There is no possibility of sending to the Earth for a repairman. The machine must be able to sense when it is sick and skillfully doctor its own illnesses. A computer is needed that is able either to fix or replace failed computer, sensor or structural components. Such a computer, which has been called STAR (self-testing and repairing computer), is on the threshold of development. It employs redundant components, as biology does—we have two lungs and two kidneys partly because each is protection against failure of the other. But a computer can be much more redundant than a human being, who has, for example, but one head and one heart.
Because of the weight premium on deep space exploratory ventures, there will be strong pressures for continued miniaturization of intelligent machines. It is clear that remarkable miniaturization has already occurred: vacuum tubes have been replaced by transistors, wired circuits by printed circuit boards, and entire computer systems by silicon-chip microcircuitry. Today a circuit that used to occupy much of a 1930 radio set can be printed on the tip of a pin. If intelligent machines for terrestrial mining and space exploratory applications are pursued, the time cannot be far off when household and other domestic robots will become commercially feasible. Unlike the classical anthropoid robots of science fiction, there is no reason for such machines to look any more human than a vacuum cleaner does. They will be specialized for their functions. But there are many common tasks, ranging from bartending to floor washing, that involve a very limited array of intellectual capabilities, albeit substantial stamina and patience. All-purpose ambulatory household robots, which perform domestic functions as well as a proper nineteenth-century English butler, are probably many decades off. But more specialized machines, each adapted to a specific household function, are probably already on the horizon.
It is possible to imagine many other civic tasks and essential functions of everyday life carried out by intelligent machines. By the early 1970s, garbage collectors in Anchorage, Alaska, and other cities won wage settlements guaranteeing them salaries of about $20,000 per annum. It is possible that the economic pressures alone may make a persuasive case for the development of automated garbage-collecting machines. For the development of domestic and civic robots to be a general civic good, the effective re-employment of those human beings displaced by the robots must, of course, be arranged; but over a human generation that should not be too difficult—particularly if there are enlightened educational reforms. Human beings enjoy learning.
We appear to be on the verge of developing a wide variety of intelligent machines capable of performing tasks too dangerous, too expensive, too onerous or too boring for human beings. The development of such machines is, in my mind, one of the few legitimate “spinoffs” of the space program. The efficient exploitation of energy in agriculture—upon which our survival as a species depends—may even be contingent on the development of such machines. The main obstacle seems to be a very human problem, the quiet feeling that comes stealthily and unbidden, and argues that there is something threatening or “inhuman” about machines performing certain tasks as well as or better than human beings; or a sense of loathing for creatures made of silicon and germanium rather than proteins and nucleic acids. But in many respects our survival as a species depends on our transcending such primitive chauvinisms. In part, our adjustment to intelligent machines is a matter of acclimatization. There are already cardiac pacemakers that can sense the beat of the human heart; only when there is the slightest hint of fibrillation does the pacemaker stimulate the heart. This is a mild but very useful sort of machine intelligence. I cannot imagine the wearer of this device resenting its intelligence. I think in a relatively short period of time there will be a very similar sort of acceptance for much more intelligent and sophisticated machines. There is nothing inhuman about an intelligent machine; it is indeed an expression of those superb intellectual capabilities that only human beings, of all the creatures on our planet, now possess.
CHAPTER 21
THE PAST AND
FUTURE OF AMERICAN
ASTRONOMY
What has been done is little—scarcely a beginning; yet it is much in comparison with the total b
lank of a century past. And our knowledge will, we are easily persuaded, appear in turn the merest ignorance to those who come after us. Yet it is not to be despised, since by it we reach up groping to touch the hem of the garment of the Most High.
AGNES M. CLERKE,
A Popular History of Astronomy
(London, Adam and Charles Black, 1893)
THE WORLD has changed since 1899, but there are few fields which have changed more—in the development of fundamental insights and in the discovery of new phenomena—than astronomy. Here are a few titles of recent papers published in the scientific magazines The Astrophysical Journal and Icarus: “G240-72: A New Magnetic White Dwarf with Unusual Polarization,” “Relativistic Stellar Stability: Preferred Frame Effects,” “Detection of Interstellar Methylamine,” “A New List of 52 Degenerate Stars,” “The Age of Alpha Centauri,” “Do OB Runaways Have Collapsed Companions?,” “Finite Nuclear-size Effects on Neutrino-pair Bremsstrahlung in Neutron Stars,” “Gravitational Radiation from Stellar Collapse,” “A Search for a Cosmological Component of the Soft X-ray Background in the Direction of M31,” “The Photochemistry of Hydrocarbons in the Atmosphere of Titan,” “The Content of Uranium, Thorium and Potassium in the Rocks of Venus as Measured by Venera 8,” “HCN Radio Emission from Comet Kohoutek,” “A Radar Brightness and Altitude Image of a Portion of Venus” and “A Mariner 9 Photographic Atlas of the Moons of Mars.” Our astronomical ancestors would have extracted a glimmer of meaning from these titles, but I think their principal reaction would have been one of incredulity.
WHEN I WAS ASKED to chair the 75th Anniversary Committee of the American Astronomical Society in 1974, I thought it would provide a pleasant opportunity to acquaint myself with the state of our subject at the end of the past century. I was interested to see where we had been, where we are today, and if possible, something of where we may be going. In 1897 the Yerkes Observatory, then the largest telescope in the world, was given a formal dedication, and a scientific meeting of astronomers and astrophysicists was held in connection with the ceremony. A second meeting was held at the Harvard College Observatory in 1898 and a third at the Yerkes Observatory in 1899, by which time what is now the American Astronomical Society had been officially founded.
The astronomy of 1897 to 1899 seems to have been vigorous, combative, dominated by a few strong personalities and aided by remarkably short publication times. The average time between submission and publication for papers in the Astrophysical Journal (Ap. J.) in this period seems to be better than in Astrophysical Journal Letters today. The fact that a great many papers were from the Yerkes Observatory, where the journal was edited, may have had something to do with this. The opening of the Yerkes Observatory at Williams Bay, Wisconsin—which has the year 1895 imprinted upon it—was delayed more than a year because of the collapse of the floor, which narrowly missed killing the astronomer E. E. Barnard. The accident is mentioned in Ap. J. (6:149), but one finds no hint of negligence there. However, the British journal Observatory (20:393), clearly implies careless construction and a cover-up to shield those responsible. We also discover on the same page of Observatory that the dedication ceremonies were postponed for some weeks to accommodate the travel schedule of Mr. Yerkes, the robber-baron donor. The Astrophysical Journal says that “the dedication ceremonies were necessarily postponed from October 1, 1897,” but does not say why.
Ap. J. was edited by George Ellery Hale, the director of the Yerkes Observatory, and by James E. Keeler, who in 1898 became the director of the Lick Observatory on Mount Hamilton in California. However, there was a certain domination of Ap. J. by Williams Bay, perhaps because the Lick Observatory dominated the Publications of the Astronomical Society of the Pacific (PASP) in the same period. Volume 5 of the Astrophysical Journal has no fewer than thirteen plates of the Yerkes Observatory, including one of the powerhouse. The first fifty pages of Volume 6 have a dozen more plates of the Yerkes Observatory. The Eastern dominance of the American Astronomical Society is also reflected by the fact that the first president of the Astronomical and Astrophysical Society of America was Simon Newcomb, of the Naval Observatory in Washington, and the first vice presidents, Young and Hale. West Coast astronomers complained about the difficulties in traveling to the third conference of astronomers and astrophysicists at Yerkes and seem to have voiced some pleasure that promised demonstrations with the Yerkes 40-inch refractor for this ceremony had to be postponed because of cloudy weather. This was about the most in the way of interobservatory rancor that can be found in either journal.
But in the same period Observatory had a keen nose for American astronomical gossip. From Observatory we find that there was a “civil war” at the Lick Observatory and a “scandal” associated with Edward Holden (the director before Keeler), who is said to have permitted rats in the drinking water at Mount Hamilton. It also published a story about a test chemical explosion scheduled to go off in the San Francisco Bay Area and to be monitored by a seismic device on Mount Hamilton. At the appointed moment, no staff member could see any sign of needle deflection except for Holden, who promptly dispatched a messenger down the mountain to alert the world to the great sensitivity of the Lick seismometer. But soon up the mountain came another messenger with the news that the test had been postponed. A much faster messenger was then dispatched to overtake the first and an embarrassment to the Lick Observatory was, Observatory notes, narrowly averted.
The youth of American astronomy in this period is eloquently reflected in the proud announcement in 1900 that the Berkeley Astronomical Department would henceforth be independent of the Civil Engineering Department at the University of California. A survey by Professor George Airy, later the British Astronomer Royal, regretted being unable to report on astronomy in America in 1832 because essentially there was none. He would not have said that in 1899.
There is never much sign in these journals of the intrusion of external (as opposed to academic) politics, except for an occasional notice such as the appointment by President McKinley of T. J. J. See as professor of mathematics to the U.S. Navy, and a certain continuing chilliness in scientific debates between the personnel of the Lick and Potsdam (Germany) Observatories.
Some signs of the prevailing attitudes of the 1890s occasionally trickle through. For example, in a description of an eclipse expedition to Siloam, Georgia, on May 28, 1900: “Even some of the whites were lacking in a very deep knowledge of things ‘eclipse-wise.’ Many thought it was a money-making scheme and what I intended to charge for admission was a very important question, frequently asked. Another idea was that the eclipse could be seen only from the inside of my observatory … Just here I wish to express my appreciation of the high moral tone of the community, for, with a population of only 100, including the immediate neighborhood, it sustains 2 white and 2 colored churches and during my stay I did not hear a single profane word … As an unsophisticated Yankee in the Southland, unused to Southern ways, I naturally made many little slips that were not considered ‘just the thing.’ The smiles at my prefixing ‘Mr.’ to the name of my colored helper caused me to change it to ‘Colonel,’ which was entirely satisfactory to everybody.”
A board of visitors was appointed to resolve some (never publicly specified) problems at the U.S. Naval Observatory. A report of this group—which consisted of two obscure senators and Professors Edward C. Pickering, George C. Comstock and Hale—is illuminating because it mentions dollar amounts. We find that the annual running costs of the major observatories in the world were: Naval Observatory, $85,000; Paris Observatory, $53,000; Greenwich Observatory (England), $49,000; Harvard Observatory, $46,000; and Pulkowa Observatory (Russia), $36,000. The salaries of the two directors of the U.S. Naval Observatory were $4,000 each, and at the Harvard Observatory, $5,000. The distinguished board of visitors recommended that in a “schedule of salaries which could be expected to attract astronomers of the class desired,” the salary of directors of observatories should be $6,000. At the Naval Observatory, co
mputers (exclusively human at the time) were paid $1,200 per annum, but at the Harvard Observatory only $500 per annum, and were almost exclusively women. In fact, all salaries at Harvard, except for the director’s, were significantly lower than at the Naval Observatory. The committee stated: “The great difference in salaries at Washington and Cambridge, especially for the officers of lower grade, is probably unavoidable. This is partly due to Civil Service Rules.” An additional sign of astronomical impecuniosity is the announcement of the post of “volunteer research assistant” at Yerkes, which had no associated pay but which was said to provide good experience for students with higher degrees.
Then, as now, astronomy was besieged by “paradoxers,” proponents of fringe or crackpot ideas. One proposed a telescope with ninety-one lenses in series as an alternative to a telescope with a smaller number of lenses of larger aperture. The British in this period were similarly plagued but in perhaps a gentler way. For example, an obituary in the Monthly Notices of the Royal Astronomical Society (59:226) of Henry Perigal informs us that the deceased had celebrated his ninety-fourth birthday by becoming a member of the Royal Institution, but was elected a Fellow of the Royal Astronomical Society in 1850. However, “our publications contain nothing from his pen.” The obituary describes “the remarkable way in which the charm of Mr. Perigal’s personality won him a place which might have seemed impossible of attainment for a man of his views; for there is no masking the fact that he was a paradoxer pure and simple, his main conviction being that the Moon did not rotate, and his main astronomical aim in life being to convince others, and especially young men not hardened in the opposite belief, of their grave error. To this end he made diagrams, constructed models, and wrote poems; bearing with heroic cheerfulness the continued disappointment of finding none of them of any avail. He has, however, done excellent work apart from this unfortunate misunderstanding.”
