Chronometry and the STEM Cycle

27 November 2014

Thursday


Lund Astronomical Clock

An interesting article on NPR about a new atomic clock being developed by NIST scientists, New Clock May End Time As We Know It, was of great interest to me. Immediately intrigued, I wrote a post on my other blog in which I suggested that the new clock might be used to update the “Einstein’s box” thought experiment (also known as the clock-in-a-box thought experiment). While I would like to follow up on this idea at some time, today I want to write about advanced chronometry in the context of the STEM cycle.

What if, in the clock-in-a-box thought experiment, we replace the clock with one so sensitive it can also function to measure the height of the box?

What if, in the clock-iin-a-box thought experiment, we replace the clock with one so sensitive it can also function to measure the height of the box?

Atomic clocks are among the most precise scientific instruments ever developed. As such, precision clocks offer a good illustration of the STEM cycle, which I identified as the definitive feature of industrial-technological civilization. While this illustration is contemporary, there is nothing new about the use of the most advanced science, technology, and engineering available being employed in chronometry.

The Tower of the Winds in Athens held one of the most advanced timekeeping devices in classical antiquity; the tower still stands, but the mechanism is long gone.

The Tower of the Winds in Athens held one of the most advanced timekeeping devices in classical antiquity; the tower still stands, but the mechanism is long gone.

The earliest sciences, already developed in classical antiquity, were mathematics and astronomy. These early scientific disciplines were applied to the construction of timekeeping mechanisms. Among the most interesting technological artifacts of the ancient world are the clock once installed in the Tower of the Winds in Athens (which was described in antiquity, but which no longer exists) and the Antikythera mechanism, the corroded remains of which were dredged up from a shipwreck off the Greek island of Antikythera (while discovered by sponge divers in 1900, the site is still yielding finds). A classic paper on the Tower of the Winds compares these two technologies: “This is a field in which ancient literature is curiously meager, as we well know from the complete lack of any literary reference to a technology that could produce the Antikythera Mechanism of the same date.” (“The Water Clock in the Tower of the Winds,” Joseph V. Noble and Derek J. de Solla, American Journal of Archaeology, Vol. 72, No. 4, Oct., 1968, pp. 345-355) Both of these artifacts are concerned with chronometry, which demonstrates that the most advanced technologies, then and now, have been employed in the measurement of time.

antikythera mechanism reconstruction

The advent of high technology as we know it today — unprecedented in human history — has been the result of the advent of a new kind of civilization — industrial-technological civilization — and the use of advanced technologies in chronometry provides a useful lens with which to view one of the unique features of our civilization today, which I call the STEM cycle. The acronym STEM is familiar in educational contexts in order to refer to education and training in science, technology, engineering, and mathematics, so I have taken over this acronym as the name for one of the socioeconomic processes that lies at the heart of our civilization: Science seeks to understand nature on its own terms, for its own sake. Technology is that portion of scientific research that can be developed specifically for the realization of practical ends. Engineering is the industrial implementation of a technology. Mathematics is the common language in which the elements of the cycle are formulated. A feedback loop of science driving technology, driving engineering, driving more science, characterizes industrial-technological civilization. This is the STEM cycle.

Ammonia maser frequency standard built 1949 at the US National Bureau of Standards (now National Institute of Standards and Technology) by Harold Lyons and associates. (Wikipedia)

Ammonia maser frequency standard built 1949 at the US National Bureau of Standards (now National Institute of Standards and Technology) by Harold Lyons and associates. (Wikipedia)

The distinctions between science, technology, and engineering are not absolute — far from it. To employ a terminology I developed elsewhere, I would say that science is only weakly distinct from technology, technology is only weakly distinct from engineering, and engineering is only weakly distinct from science. In some contexts any two elements of the STEM cycle are identical, while in other contexts of the STEM cycle they are starkly contrasted. This is not due to inconsistency, but rather to the fact that science, technology, and engineering are open-textured concepts; we could adopt conventional distinctions that would make them strongly distinct, but this would be contrary to usage in ordinary language and would only result in confusion. Given the lack of clear distinctions among science, technology, and engineering, where we draw the dividing lines within the STEM cycle is to some degree arbitrary — we could describe this cycle in different terms, employing different distinctions — but the cycle itself is not arbitrary. By any other name, it drives industrial-technological civilization.

STEM cycle 1

The clock that was the inspiration for this post — the new strontium atomic clock, described in JILA Strontium Atomic Clock Sets New Records in Both Precision and Stability, and the subject of a scientific paper, An optical lattice clock with accuracy and stability at the 10−18 level by B. J. Bloom, T. L. Nicholson, J. R. Williams, S. L. Campbell, M. Bishof, X. Zhang, W. Zhang, S. L. Bromley, and J. Ye (a preprint of the article is available at Arxiv) — is instructive in several respects. In so far as we consider atomic clocks to be a generic “technology,” the strontium clock represents the latest and most advanced instance of this technology yet constructed, a more specific form of technology, the optical lattice clock, within the more generic division of atomic clocks. The sciences involved in the conceptualization of atomic clocks are fundamental: atomic physics, quantum theory, relativity theory, thermodynamics, and optics. Atomic clocks are a technology built from another technologies, including advanced materials, lasers, masers, a vacuum chamber, refrigeration, and computers. Building the technology into an optimal device involves engineering for dependability, economy, miniaturization, portability, and refinements of design.

JILA's experimental atomic clock based on strontium atoms held in a lattice of laser light is the world's most precise and stable atomic clock. The image is a composite of many photos taken with long exposure times and other techniques to make the lasers more visible. (Ye group and Baxley/JILA)

JILA’s experimental atomic clock based on strontium atoms held in a lattice of laser light is the world’s most precise and stable atomic clock. The image is a composite of many photos taken with long exposure times and other techniques to make the lasers more visible. (Ye group and Baxley/JILA)

The NIST web page notes that, “NIST invests in a number of atomic clock technologies because the results of scientific research are unpredictable, and because different clocks are suited for different applications.” (For further background on atomic clocks at NIST cf. A New Era for Atomic Clocks.) The new record breaking clocks in terms of stability and accuracy are experimental devices; the current standard for timekeeping is the NIST-F2 “cesium fountain” atomic clock. The transition from the previous standard timekeeping, NIST-F1, to the present standard, NIST-F2, is largely a result of engineering refinements of the earlier atomic clock. Even the experimental strontium clock is likely to be soon surpassed. JILA Strontium Atomic Clock Sets New Records in Both Precision and Stability quotes Jun Ye as saying, “We already have plans to push the performance even more, so in this sense, even this new Nature paper represents only a ‘mid-term’ report. You can expect more new breakthroughs in our clocks in the next 5 to 10 years.”

STEM cycle epiphenomena 10

The engineering refinement of high technology has two important consequences:

1) inexpensive, widely available devices (which I will call the ubiquity function), and…

2) improved, cutting edge devices that improve the precision of measurement (which I will call the meliorative function), sometimes improved by an order of magnitude (or several orders of magnitude).

These latter devices, those that represent greater precision, are not likely to be inexpensive or widely available, but as the STEM cycle continues to advance science, technology, and engineering in a regular and predictable manner, the older generation of technology becomes widely available and inexpensive as new technologies take their place on the expensive cutting edge. However, these cutting edge technologies are in turn displaced by newer technologies, and the cycle continues. Thus there is a relationship — an historical relationship — between the two consequences of the engineering refinement of technology. Both of these phases in the life of a technology affect the practice of science. NIST Launches a New U.S. Time Standard: NIST-F2 Atomic Clock quotes NIST physicist Steven Jefferts, lead designer of NIST-F2, as saying, “If we’ve learned anything in the last 60 years of building atomic clocks, we’ve learned that every time we build a better clock, somebody comes up with a use for it that you couldn’t have foreseen.”

NIST-F2

Widely available precision measurement devices (the ubiquity function) bring down the cost of scientific research and we begin to see science cropping up in all kinds of interesting and unexpected places. The development of computer technology and then the miniaturization of computers had the unintended result of making computers inexpensive and widely available. This, in turn, has meant that everyone doing science carries a portable computer with them, and this widely available computational power (which I have elsewhere called the computational infrastructure of civilization) has transformed how science is done. NIST Atomic Devices and Instrumentation (ADI) now builds “chip-scale” atomic clocks, which is both commercializing and thereby democratizing atomic clock technology in a form factor so small that it could be included in a cell phone (or whatever mobile device form factor you prefer). This is perfect illustration of the ubiquity function in an engineering application of atomic clock technology.

New cutting edge precision measurement devices (the meliorative function), employed only by the governments and industries that can afford to push the envelope with the latest technology, are scientific instruments of great sensitivity; increasing the precision of the measurement of time by an order of magnitude opens up new possibilities the consequences of which cannot be predicted. What can be predicted, however, is the present generation of high precision measurement devices make it possible to construct the next generation of precision measurement devices, which exceed the precision of the previous generation of devices. A clock built to a new design that is far more precise than its predecessors (like the strontium atomic clock) may not necessarily find its cutting edge scientific application exclusively in the measurement of time (though, again, it might do that also), but as a scientific instrument of great sensitivity it suggests uses throughout the sciences. A further distinction can be made, then, between instruments used for the purposes they were intended to serve, and instruments that are exapted for unintended uses.

A loosely-coupled STEM cycle is characterized primarily by the ubiquity function, while a tightly-coupled STEM cycle is characterized primarily by the meliorative function. Human civilization has always involved a loosely-coupled STEM cycle, sometimes operating over thousands of years, with no apparent relationship between science, technology, and engineering. Technological progress was slow and intermittent under these conditions. However, the productivity of industrial-technological civilization is such that its STEM cycle yields both the ubiquity function and the meliorative function, which means that there are in fact multiple STEM cycles running concurrently, both loosely-coupled and tightly-coupled.

The research and development branch of a large business enterprise is the conscious constitution of a limited, tightly-coupled STEM cycle in which only that science is pursued that is expected to generate specific technologies, and only those technologies are developed that can be engineered into marketable products. An open loop STEM cycle, loosely-coupled STEM cycle, or exaptations of the STEM cycle are seen as wasteful, but in some cases the unintended consequences from commercial enterprises can be profound. When Arno Penzias and Robert Wilson were hired by Bell Labs, it was with the promise that they could use the Holmdel Horn Antenna for pure science once they had done the work that Bell Labs would pay them for. As it turned out, the actual work of tracing down interference resulted in the discovery of cosmic microwave background radiation (CMBR), earning Penzias and Wilson the Nobel prize. An engineering problem became a science problem: how do you explain the background interference that cannot be eliminated from electronic devices?

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