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Authors: George B. Dyson

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In November 1662, Newton, Boyle, and others on the Royal Society's Council established the position of curator of experiments “and order'd that Mr Hooke should come and sit among them, and both bring in every Day three or four of his own Experiments, and take care of such others as should be recommended to him.”
11
The ensuing thirty-six years of experimental research were interrupted only by a brief recess during the worst months of the plague in 1665, followed by a period of distraction after the great fire of 1666, when Hooke was commissioned to help survey the City of London so that property could be rebuilt. He was paid handsomely by the landowners, but continued to live penuriously, “as was evident by a large Iron Chest of Money found after his Death, which had been lock'd down with the Key in it, with a date of the Time, by which it appear'd to have been so shut up for above thirty Years.”
12

Hooke's pendulum clock escapement saw universal use, as did countless other inventions of his, including the universal joint, that have helped our world go round smoothly ever since. His mechanism for regulating pocket watches and chronometers, based on the oscillation of a delicately coiled spring, regulated industry, commerce, and
navigation for the next three hundred years. Although Hooke did not invent the microscope, he greatly improved it, and with the publication of his
Micrographia
in 1665, he established the cellular structure of living organisms and otherwise defined the field. He dabbled as an architect, designing the buildings that housed the Royal Society, the College of Physicians, the British Museum, and the Hospital of St. Mary of Bethlehem, or Bedlam. He is remembered for Hooke's law of elasticity and forgotten as the discoverer of the optical interference patterns known as Newton's rings.

When new inventions were presented to the Royal Society, Hooke either claimed to have invented them earlier or showed how they could be improved. When Leibniz exhibited a calculating machine in January 1673, Hooke complained, “it seemed to me so complicated with wheels, pinions, cantrights, springs, screws, stops, and truckles, that I could not perceive it ever to be of any great use. . . . It could only be fit for great persons to purchase, and for great force to remove and manage, and for great wits to understand and comprehend.” In contrast, Hooke announced that “I have an instrument now making, which will perform the same effects [and] will not have a tenth part of the number of parts, and not take up a twentieth part of the room.”
13
The record shows that on 5 March 1673, “he produced his arithmetical engine, mentioned by him in the meeting of February 5, and showed the manner of its operation, which was applauded.” But Hooke's invention “whereby in large numbers, for multiplication or division, one man may be able to do more than twenty by the common way of working arithmetic” remained as sparsely documented as his spring-powered model representing one of some thirty different envisioned species of flying machines. The arithmetic engine was listed among the artificial rarities in the collection of Gresham College in 1681, and thereafter disappeared.

Hooke neglected most opportunities to reap reward. “Whether this mistake resulted from the multiplicity of his Business which did not allow him a sufficient time,” wrote Richard Waller, “or from the fertility of his Invention which hurried him on, neglecting the former Discoveries . . . tho' there wanted some small matter to render their use more practicable and general, I know not.”
14
If anyone could be said to have thought of everything, it was Hooke. He developed a philosophical algebra by which to grasp multiple avenues of thought at a single time, making it inevitable, even without unscrupulous behavior on the part of some of his colleagues, that competitors would appear to be taking credit for his ideas. His contributions included a theory of gravitation and celestial mechanics, of which, said Aubrey, “Mr. Newton haz made a demonstration, not at all owning he receiv'd
the first Intimation of it from Mr. Hooke.” Eventually, Hooke grew bitter over both real and perceived expropriations of his work and revealed many of his later inventions only in the form of cryptic anagrams, carrying the details with him to his grave. “I wish he had writt plainer, and afforded a little more paper,” was Aubrey's chief complaint.
15

Hooke was acquainted with the elder Thomas Hobbes, but “found him to lard and seal every asseveration with a round oath, to undervalue all other men's opinions and judgments, to defend to the utmost what he asserted though never so absurd.”
16
Their destinies were intertwined: it was Hooke's concept of long-distance communication that would bring Hobbes's Leviathan to life. Although Hooke did not go as far as Hobbes in assigning a material existence to the soul, he speculated more precisely on the physical operation of the mind.

The mystery, to Hooke, was not that we are able to perceive, remember, and generate new concepts from one moment to the next, but how the mind keeps track of temporal sequence while preserving random access to its store of memories and ideas. Hooke's solution—like the mechanism he developed for the regulation of chronometers—took the form of a coiled spring: “There is as it were a continued Chain of Ideas coyled up in the Repository of the Brain, the first end of which is farthest removed from the Center or Seat of the Soul where the Ideas are formed, which is always the Moment present when considered: And therefore according as there are a greater number of [layers of] these Ideas between the present Sensation or Thought in the Center, and any other, the more is the Soul apprehensive of the Time interposed.”
17

To estimate the storage capacity of the human brain, Hooke calculated the number of thoughts that could be registered per second, hour, day, year, and lifetime—“to take a round sum but 21 hundred Millions.” He reduced to 100 million the number that the average person might remember, who “consequently must have as many distinct Ideas.” Hooke then drew on his firsthand observations of microorganisms to argue that this many ideas might easily fit inside the brain: “I see no Reason why all these may not actually be contained within the Sphere of Activity of the Soul. . . . For if we consider in how small a bulk of Body there may be as many distinct living creatures as are here supposed Ideas, and every of these Creatures perfectly formed and endued with all its Vegetative and Animal Functions, and with sufficient room also left for it to move it self to and fro among and between all the rest . . . we shall not need to fear any Impossibility to find out room in the Brain.”
18

As early as 17 February 1664 the Royal Society urged “that Mr. Hooke set down in writing and produce to the Council his whole apparatus and management for speedy intelligence,”
19
but nothing was forthcoming until 29 February 1672, when “he proposed a way for a very speedy conveyance of intelligence from place to place by the sight assisted with telescopes, to be employed on high places, by the correspondents using a secret character. . . . The paper of this proposition, and the particulars of the manner of practising it, were read, but not left by Mr. Hooke to be registered, but taken away by him.”
20
The council ordered “that some experiment should be made of this proposition at the next meeting,” and on 7 March a test was conducted across the Thames. “The contrivance was applauded as very ingenious . . . [but] the President objected, that the use of it would be often hindered by hazy weather.”
21

In a disclosure that was finally delivered and recorded in 1684, Hooke prescribed an alphabet of twenty-four symbols, constructed of thin wood and rigged via pulleys and control lines so as to be exposed as required from behind an elevated wooden screen. “By these Contrivances, the Characters may be shifted almost as fast, as the same may be written; so that a great Quantity of Intelligence may be, in a very short Time, communicated.”
22
For nighttime use, Hooke proposed a 2 × 5 array of lanterns “disposed in a certain Order, which may be veiled, or discovered, according to the Method of the Character agreed on; by which, all Sorts of Letters may be discovered clearly, and without Ambiguity,”
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foreshadowing the shutter telegraphs that would be instituted by the British Admiralty in another hundred years. Finally, confirming the intimate association between telecommunications and cryptography, Hooke noted that by “cruptography” (as he spelled it) the arbitrary mapping between symbols and letters permits “the whole alphabet [to] be varied 10,000 ways; so that none but the two extreme correspondents shall be able to discover the information conveyed.”
24

Hooke specified single-character control codes to be displayed above the message area during transmission, providing eleven examples of these out-of-band signals, of which Holzmann and Pehrson noted that “at least eight are control codes that can be found in most modern data communication protocols, and some of these (i.e., the rate control codes) only in the most recent designs.”
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Hooke confidently predicted that “things may be made so convenient, that the same Character may be seen at
Paris
, within a Minute after it hath been exposed at
London
, and the like in Proportion for greater Distances; and that the Characters may be exposed so quick after
one another, that a Composer shall not much exceed the Exposer in Swiftness.”
26

By the end of the next century, optical telegraph networks spanned most of Europe, led by a system constructed by Claude and Abraham Chappe in France. In 1801, with designs on England, Napoléon commissioned an optical telegraph able to span the English Channel; when tested over equivalent distances, it worked. Claude Chappe (1763–1805) had attempted to construct an electric telegraph in 1790, but soon abandoned electricity in favor of optical signals relayed by mechanical display. The French Revolution was in full swing. The new government was open to new ideas, but Chappe's prototype installation was destroyed twice by revolutionary mobs who suspected it was a device for communicating with the imprisoned Louis XVI. Chappe's network, inaugurated by a 130-mile line between Paris and Lille in 1794, reached a total length of approximately 3,000 miles, staffed by some three thousand operators at 556 stations, in 1852. Stations were about 6 miles apart. Signals could be relayed in a few seconds, but the lines ran much slower in practice, with actual throughput about two signals per minute or less. Transit over the 475 miles and 120 stations from Paris to Toulon (on the Mediterranean) took “10 or 12 minutes” if the weather was clear. Messages were encrypted against interception or adulteration en route.

Chappe's coding improved on the one-to-one mapping between transmitted symbols and written alphabet proposed by Hooke. Two independently rotating indicators (each capable of seven distinguishable positions) were mounted at the ends of a central regulator that alternated between two positions. There were thus ninety-eight (7 × 7 × 2) recognizably different regulator/indicator positions, of which six were reserved for special indications, leaving ninety-two signals for conveying the message code. Taking a page from Polybius, the Chappes instituted a ninety-two-page codebook with ninety-two words or phrases on each page. The first page encoded the alphabet, numerals, and most frequently transmitted syllables, which could be transmitted as a single signal followed by folding in the indicators “closed.” The following ninety-one pages, each listing ninety-two words and phrases, were composite signals, transmitted as two consecutive signals designating page number and line.

This system allowed 8,464 different meanings to be encoded as signal pairs. In 1799 the code space was increased to a total of 25,392 entries with the addition of two auxiliary books. A large number of meanings were represented by the combination of comparatively few symbols, using some of the same principles of data compression
prevalent today. As Alan Turing would later demonstrate by the design of his theoretical Turing machine, any arbitrarily complicated symbol, or sequence of symbols, could be captured as a state of mind, while the representation of any state of mind could be transmitted by running the process the other way. The codebooks developed by the Chappes were a concrete example of a computable function relating a given scanned symbol or short sequence of symbols to an equivalent state of mind.

Chappe's system was imitated, with modifications, throughout the developed world. In Russia, 1,320 people were employed just to operate the main line from St. Petersburg to the Prussian frontier. In England, the 200-mile line between London and Plymouth was able to convey a timing signal and return an acknowledgment in under three minutes when the weather was clear. Fragments of the optical telegraph networks survived, especially in island-studded Scandinavia, for many years after electric telegraphy was introduced. According to Holzmann and Pehrson, Claude Chappe and his Swedish counterpart, Abraham Edelcrantz, were the “true pioneers of data networking” and managed “to solve many subtle problems to enable operators to transfer messages smoothly over long chains of stations . . . ideas [that] have been rediscovered only recently by the designers of modern digital protocols.”
27
In a fitting reprise of the original message transmitted to Mycenae from Troy, one of the last messages distributed in part by optical telegraph reported the fall of Sevastopol during the Crimean War in 1855. Electric telegraphs, however, were already in use by the British in the final stage of the siege, and on the Russian side electrical connections reaching back to St. Petersburg were already complete as well.

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