Tuesday, April 13, 2021

Technology in the ancient world: time


We don't think of the ancient world as being one that was rich in technological innovation or progress. And yet in a number of areas, there were very significant developments in technology -- in ships, mining, fortification, siege engines, road-building, and bridges and aqueducts, for example. And there is the intriguing example of the Antikythera mechanism (link), dating from the first century BCE and lacking a clear technological context, but establishing firmly the availability of advanced metal-working techniques and complex geared mechanisms. (Two fascinating videos are linked on the earlier blogpost on the Antikythera mechanism.) 

John Peter Oleson's The Oxford Handbook of Engineering and Technology in the Classical World provides an extensive survey of the current state of knowledge about the topic, drawing upon the work of dozens of experts in classical scholarship. Here is the table of contents of the volume, from which the reader can get a very good idea of the topics and technologies considered:

Part I Sources  

1. Ancient Written Sources for Engineering and Technology, Serafina Cuomo  2. Representations of Technical Processes, Roger Ulrich  3. Historiography and Theoretical Approaches, Kevin Greene  

Part II Primary, Extractive Technologies  

4. Mining and Metallurgy, Paul T. Craddock  5. Quarrying and Stoneworking, J. Clayton Fant  6. Sources of Energy and Exploitation of Power, Orjan Wikander  7. Greek and Roman Agriculture, Evi Margaritis and Martin K. Jones  8. Animal Husbandry, Hunting, Fishing, and Fish Production, Geoffrey Kron 

Part III Engineering and Complex Machines  

9. Greek Engineering and Construction, Fredrick A. Cooper  10. Roman Engineering and Construction, Lynne Lancaster  11. Hydraulic Engineering and Water Supply, Andrew I. Wilson  12. Tunnels and Canals, Klaus Grewe  13. Machines in Greek and Roman Technology, Andrew I. Wilson  

Part IV Secondary Processes and Manufacturing  

14. Food Processing and Preparation, Robert I. Curtis  15. Large-Scale Manufacturing, Standardization, and Trade, Andrew I. Wilson  16. Metalworking and Tools, Carol Mattusch  17. Woodworking, Roger B. Ulrich  18. Textile Production, John P. Wild  19. Tanning and Leather, Carol van Driel-Murray  20. Ceramic Production, Mark Jackson and Kevin Greene  21. Glass Production, E. Marianne Stern 

Part V Technologies of Movement and Transport  

22. Land Transport, Part 1: Roads and Bridges, Lorenzo Quilici  23. Land Transport, Part 2: Riding, Harnesses, and Vehicles, Georges Raepsaet  24. Sea Transport, Part 1: Ships and Navigation, Sean McGrail  25. Sea Transport, Part 2: Harbors, David J. Blackman  

Part VI Technologies of Death  

26. Greek Warfare and Fortification, Philip de Souza  27. Roman Warfare and Fortification, Gwyn Davies  

Part VII Technologies of the Mind  

28. Information Technologies: Writing, Book Production, and the Role of Literacy, Willy Clarysse and Katelijn Vandorpe  29. Timekeeping, Robert Hannah  30. Technologies of Calculation, Part 1: Weights and Measures (Charlotte Wikander), Part 2: Coinage (Andrew Meadows), Part 3: Practical Mathematics (Karin Tybjerg) 31. Gadgets and Scientific Instruments, Orjan Wikander  32. Inventors, Invention, and Attitudes toward Innovation, Kevin Greene

Part VIII Ancient Technologies in the Modern World  

33. Expanding Ethnoarchaeology: Historical Evidence  and Model-Building in the Study of Technological Change, Michael B. Schiffer  

Many of the technologies described here are important and interesting, but familiar: ships, mines, fortifications, and other common interactions with the natural world. The most surprising technology innovations are described in Part VII, "Technologies of the Mind", and here there is more information about "high technology" in the ancient world. Orjan Wikander describes "gadgets and instruments" in chapter 31, which is a topic that sheds more light on advanced technical and scientific innovation -- and therefore provides some intellectual background for the design and fabrication of the Antikythera mechanism. What is most eye-opening about the details of the Antikythera mechanism is the intricate design of the gearing system that it embodied and the advanced metal-working techniques that it presupposed for fabrication (cutting precision gear wheels and most puzzling, cutting concentric tubes to convey motion from one gear assembly to an output ring). Wikander makes it clear that the principle of geared machines was familiar in the Hellenistic world (for advanced mathematicians and philosophers, at least). Field and Wright report on a Byzantine sundial calendar geared device dating from about 500 AD, whose gears are very similar to those used in the Antikythera device; link. They take this as evidence of an ongoing engineering tradition in the Greek world of fabrication of geared devices. (Notably, the sundial calendar is substantially less complex than the Antikythera mechanism, implying a loss of technological knowledge over the intervening 500 years.) 

But there is an interesting complication about these high-tech astronomical devices for the history of technology: these devices were advanced and sophisticated, but they appear to have had little practical utility. It appears to be widely agreed, for example, that the Antikythera device had no use as a navigational instrument; instead, it appears to be an entertaining demonstration of astronomical knowledge for an elite audience. A more useful geared instrument, apparently, was the "hodometer", a wheeled and geared device that could be pulled along a route and used to measure distance. But this is an important guidepost in the study of the history of technology: the innovation and development of the "gadget" itself does not ensure its proliferation and widespread adoption. It needs to find a need within ambient society to which the gadget can be adapted in a useful way.

An interesting challenge of measurement in the ancient world was time. Robert Hannah's chapter on "Timekeeping" provides a very interesting account of shifts in both the conception of time and the means that were available or developed to measure its passage. It is evident that it is not possible to engage in the science of mechanics without a way of measuring equal intervals of time -- key variables like velocity, acceleration, inertia all require an account of distance covered per unit of time. Most fundamentally, it isn't possible to form the concept of velocity unless one has a fairly definite conception of units of time. "Fast" and "slow" are imaginable; but 4 m/s is not. 

A little bit of reflection will show that there are at least two different problems encompassed under "timekeeping". First, we may have reasons for wanting to know "what is the time of day at the moment?", by which we mean, most fundamentally, how long past sunrise (or before sunset) is it currently? And how long until dinner? In this context it is very interesting (and eyebrow-raising) to learn of "unequal hours" involved in Greek timekeeping:

Sundials helped inculcate into society the concept of the seasonal, or unequal, hour. For most purposes in antiquity, such hours were the norm. From Egypt came the notion that each day or night could be divided into 12 hours from sunrise to sunset, and another 12 from sunset to sunrise (Parker 1974: 53; Quirke 2001: 42). Since daytime and nighttime change in length with the seasons, the length of each hour therefore changed also according to the season. Only at the spring and autumn equinoxes were the hours equal through the whole day. (p. 749)

So a person's pulse (beats per sixtieth of an hour) will be different, depending on whether it is measured in daytime or nighttime. Suppose the individual's real pulse rate at equinox is 70 beats per sixtieth of an hour and it never changes. When measured on December 22 by counting beats for an hour and dividing by 60, his/her pulse will be 54 bpm; the same measurement on June 22 results in a pulse of 86 bpm. Further, length of day is influenced by latitude as well as season; so the same individual would have a different pulse rate in Miami than in Helsinki, on the same day. Measuring pulse by such a system is useless as a tool for assessing health status. And how about cooking -- what is the result of a variable hour for a 4-minute soft-boiled egg? 

The harder challenge of time measurement is the problem of measuring "duration of time" -- how many minutes it takes to walk from the agora to the Acropolis in Athens, how long it takes the arrow to fly from the archer to the target, how long the egg has been boiling. The problem of time-telling can be handled reasonably well by use of a sundial (during daylight hours) and by the position and elevation of the stars by night, but a sundial is not a practical instrument for measuring duration.

What is needed for measuring duration is an absolute measure of "equal interval of time" that can be used to measure duration -- ticks of a clock, swings of a pendulum of a certain length, vibration of a cesium atom, movement of a violin string tuned to E, movement of the fork of a tuning fork tuned to A. More exactly, what is needed is a process that occurs in the same period of time every time it is invoked; and a way of counting the number of times the event has occurred during the process to be measured. Each of the processes mentioned here identifies a discrete event that always takes the same amount of time from beginning to end. The difficult challenge is an automatic way of counting events. Mechanical clocks "count" events by advancing a geared mechanism, moving pointers on a dial. 

The water clock (clepsydra) and sand clock both served to measure duration through the idea that the flow of a liquid or viscous substance through a constrained opening takes a regular amount of time. So a bucket with a hole in the bottom was used to measure the period in which legal arguments needed to be made in Athenian proceedings (752).

Here is a novel clock mechanism that could have been used. Suppose we construct a 6.21013-meter pendulum. It has a period of 5.0 seconds. This solves the first part of the problem: an event that always takes the same amount of time. But how to count events in order to measure extended periods of time? Suppose we design a simple device in which a small bucket with volume of 10 cm^3 is fitted to a lever and is triggered by a tap of the pendulum. It empties into a calibrated glass vessel and is refilled automatically in the next several seconds. After the first cycle the calibrated vessel contains 10 cm^3; after 50 cycles the vessel contains 500 cm^3 of water and 250 seconds have elapsed. After 17,280 cycles the calibrated vessel contains 172,800 cm^3 of water (172.8 liters), and 24 hours have elapsed. The calibration of the vessel permits the user to measure the amount of time (number of swings of the pendulum) that have occurred since beginning the process, by measuring the volume of the water. A large vessel (200 liters) will permit measurement of periods extending over a full 24 hour period; a narrow vessel can be calibrated to permit precise measurement of short intervals (5 minutes). The clock will be precise to the range of 5 seconds -- perfectly sufficient for boiling 4-minute eggs. And the precision of the timepiece can be increased by shortening the pendulum; a .5 meter pendulum has a period of 1.42 seconds.

(In this example the clock was initiated at midnight, and the level of the water indicates that the time is now 10:00 am.)

(Who can direct me to the Agora patent office? All royalties will be directed to the defense fund established on behalf of Professor Socrates.)

Once we have a system for measuring intervals of time, it is possible to define and measure other important physical quantities: velocity, acceleration, the period of a pendulum, the frequency of a vibrating string, a mammal's pulse. So measurement of mid-range intervals of time is crucial to the development of physics and mechanics as well as other areas of science -- as is evident from the Renaissance scientists such as Galileo. Conversely, without such a system of time-interval measurement, many important physical laws cannot be discovered. Ancient Greek and Roman scientists had reasonably effective instruments for measuring distance, and only very limited instruments for measure elapsed time. Time on the scale of a month or a year could be measured by observation of the movements of the moon and the planets; but time on the scale of seconds and minutes could not be measured by these means.

(Wikander is best known for his research on water technologies, including especially water mills. Here is an interesting page outlining changing knowledge over the past several decades on the extent of use of water mills during the classical period (link).)

Saturday, April 10, 2021

LaCapra on the history, memory, and the Holocaust


Dominick LaCapra's History and Memory after Auschwitz is an important contribution to the topic of "history's responsibility in front of the Holocaust". His aim in this book, and elsewhere in many of his other writings, is to express his "conception of the relations among history, memory, ethics, and politics" (6). 

Here is an especially arresting sentence from the introduction:

I discuss Heinrich Himmler's famous Posen speech of October 1943, addressed to upper-level SS officers, for it may be taken as the paradigmatic assertion of the sublimity and "glory" of extreme transgression and unheard-of excess in the Nazi treatment of Jews. Often such features are marginalized or downplayed in the emphasis on factors such as the banality of evil, the well-nigh inevitable consequences of totalization (or totalitarianism), the role of bureaucratic routine and cold duty, the inertial force of social pressure, the effects of depersonalizing and fragmented relations to the other, and the significance of a massive technological framework, instrumental rationality, and industrialized mass murder. (3)

LaCapra draws attention here to the striking contrast between these fairly ordinary causal factors often highlighted in discussions of the Holocaust and the "regression to barbarism" represented by much of the treatment of Jews and the insane "sublime elation" of Himmler's speech.

LaCapra seeks to address the question of "uniqueness or comparability" of the Holocaust:

The more general point ... is that the Holocaust was "unique" in a specific, nonnumerical, and noninvidious sense. In it an extreme threshold or outer limit of transgression was crossed, and whenever that threshold or limit is crossed, something "unique" happens and the standard opposition between uniqueness and comparability is unsettled, thereby depriving comparatives (especially in terms of magnitude) of a common measure or foundation. (7)

This is a somewhat paradoxical-sounding statement, but it seems to make sense. The "killing fields" of Pol Pot were also unique, different from the Holocaust, horrific, and "an extreme threshold or outer limit of transgression". Each such crossing is "non-comparable", in the sense that each demands its own sorrow, its own lack of comprehension, and its own determination that "never again" will we permit such violations. There is no common measure; each occurrence is evil in its own unique and horrific way.

LaCapra quotes Saul Friedlander on the topic of the uniqueness of the Nazi extermination of the Jews, including especially Friedlander's view in Memory, History, and the Extermination of the Jews of Europe that "The Nazi regime attained what is, in my view, some sort of theoretical outer limit: one may envision an even larger number of victims and a technologically more efficient way of killing, but once a regime decides that groups, whatever the criteria may be, should be annihilated there and then and never be allowed to live on Earth, the ultimate has been achieved" (quoted in LaCapra, 26). LaCapra approves of this idea: "The essential consideration is that an outer limit was reached and that, once this limit is reached, something radically transgressive or incommensurable has occurred". But he also fears that this perspective may "normalize" (banalize) the Holocaust "by prompting a dogmatic assertion of absolutes, a grim competition for first place in victimhood or the type of research into similarities and differences that easily becomes diversionary and pointless" (26).

Here is LaCapra's considered judgment about how to understand the uniqueness and generalizability of the Holocaust:

I would change metaphors and note the role of a tragic grid that achieved a paramount place in the Holocaust but in other ways is also evident elsewhere in history. It is the grid that locks together perpetrator, collaborator, victim, bystander, and resister, and that also threatens to encompass the secondary witness and historian. A goal of working-through should be the better understanding of this grid and the attempt to overcome it toward a more desirable network of relations. (40-41)

And what about the historian in this tragic grid?

The historian must work out a subject-position in negotiating transference and coming to terms with his or her implication in the tragic grid of participant-positions. The conventional stance for the historian is often closest to that of the innocent bystander or onlooker. But this safe position is particularly questionable in the case of the Holocaust and other extreme or limit-events. (41)

Working through the past in any desirable fashion would thus be a process (not an accomplished state) and involve not definitive closure or full self-possession but a recurrent yet variable attempt to relate accurate, critical memory-work to the requirements of desirable action in the present. (42)

One thing that is especially noteworthy about LaCapra's approach to the topic of history, memory, and trauma is his use of some basic ideas from psychoanalysis. This is an approach that is somewhat foreign to the ideas that analytic philosophers bring to the philosophy of history, but it seems especially relevant to the question of how to confront the evils of the twentieth century. Here is a very interesting description of how LaCapra treats psychoanalysis as a tool of inquiry in history:

My basic premise in this chapter is that the fundamental concepts of psychoanalysis (such as transference, resistance, denial, repression, acting-out, and working-through) undercut the binary opposition between the individual and society, and their application to individual or collective phenomena is a matter of informed argument and research.... One should rather call into question the very idea that one is working with a more or less flimsy analogy between the individual and society and argue instead that there is nothing intrinsically "individual" about such concepts as repression and working-through. These concepts refer to processes that always involve modes of interaction, mutual reinforcement, conflict, censorship, orientation toward others, and so forth, and their relative individual or collective status should not be prejudged. (43)

This perspective makes sense in two different ways in the setting the history of the Holocaust or the Holodomor -- first, as a means of making sense of the thoughts and actions of perpetrators and victims (for example, in the lengthy Posen speech of Himmler's that LaCapra treats in detail); and second, as a way of addressing the historian's own blindspots, aversions, and rationalizations in the telling of the story. The second part of the passage following the ellipsis captures very well the situation of "collective memory" and historians' collective efforts to uncover a narrative of a complex and horrific period.

This is a good place to draw attention to the current crisis in Holocaust historiography in Poland occasioned by the libel suit successfully pursued against Jan Grabowski and Barbara Engelking for entirely legitimate assertions they made in Night Without End: The Fate of Jews in Selected Counties of Occupied Poland (published in 2018, not yet available in English translation) (link). Their work is based on thorough historical research, and aligns with the moral necessity of facing unhappy truths honestly through historical inquiry. Like Jan Gross two decades before (link), their work honestly confronts the involvement of ordinary Polish people in the murder of Poland's Jews. The government-backed insistence on "historical research supporting the national dignity of Poland" is entirely inimical towards history, truth, and memory, and is rightly opposed by historians and writers throughout the world.


Thursday, April 1, 2021

Learning and engagement


John Dewey's Democracy and Education is over a century old. But it still seems strikingly modern, even avant-garde, when compared to many pedagogical practices currently in place in both secondary and post-secondary schools. Here is one line of thought that is especially insightful: that learning is a constructive and active process for the learner, not a question of passive acquisition of "knowledge". Learning involves acquiring new ideas, new perspectives, and new questions for oneself. And these processes require an engagement on the part of the learner that is as active and creative as is the learning done by a basketball player with a great coach. A good teacher is one who can motivate and stimulate the student to taking this journey -- not one who can supply a full menu of pre-established solutions to the student.

Here is a particularly rich description of Dewey's conception of learning and the relationship between teacher and student. He formulates his thinking about the learning that children do; but I find the passage entirely applicable to university students as well.

The joy which children themselves experience is the joy of intellectual constructiveness—of creativeness, if the word may be used without misunderstanding. The educational moral I am chiefly concerned to draw is not, however, that teachers would find their own work less of a grind and strain if school conditions favored learning in the sense of discovery and not in that of storing away what others pour into them; nor that it would be possible to give even children and youth the delights of personal intellectual productiveness—true and important as are these things. It is that no thought, no idea, can possibly be conveyed as an idea from one person to another. When it is told, it is, to the one to whom it is told, another given fact, not an idea. The communication may stimulate the other person to realize the question for himself and to think out a like idea, or it may smother his intellectual interest and suppress his dawning effort at thought. But what he directly gets cannot be an idea. Only by wrestling with the conditions of the problem at first hand, seeking and finding his own way out, does he think. When the parent or teacher has provided the conditions which stimulate thinking and has taken a sympathetic attitude toward the activities of the learner by entering into a common or conjoint experience, all has been done which a second party can do to instigate learning. The rest lies with the one directly concerned. If he cannot devise his own solution (not of course in isolation, but in correspondence with the teacher and other pupils) and find his own way out he will not learn, not even if he can recite some correct answer with one hundred per cent accuracy. We can and do supply ready-made “ideas” by the thousand; we do not usually take much pains to see that the one learning engages in significant situations where his own activities generate, support, and clinch ideas—that is, perceived meanings or connections. This does not mean that the teacher is to stand off and look on; the alternative to furnishing ready-made subject matter and listening to the accuracy with which it is reproduced is not quiescence, but participation, sharing, in an activity. In such shared activity, the teacher is a learner, and the learner is, without knowing it, a teacher—and upon the whole, the less consciousness there is, on either side, of either giving or receiving instruction, the better. (chapter 12, kl 2567)

What is this process that Dewey is describing, this process of active "learning" on the part of the student? It is one in which the student is led to "engage in significant situations where his own activities generate, support, and clinch ideas"; it is a situation of active grappling with a problem that the student does not yet fully understand; it is a situation in which the student develops new cognitive tools, frameworks, and questions through the active and engaged mental struggle she has willingly undertaken. She has grown intellectually; she has the excitement of realizing that her perspective and understanding of something important has changed and deepened. The language of gestalt psychology is suggestive here -- the sudden shift of a set of lines on paper into a representation of a smiling face, the rearrangement of one's thought processes so a confusing set of words and ideas suddenly make sense. It is something like what Kuhn describes as a paradigm shift, except that it is a continual process of intellectual change.

What does Dewey mean here by saying that an idea cannot be conveyed from one person to another? He does not doubt that words, sentences, and paragraphs can be shared, or that the student cannot incorporate those words into sentences. But his key point is profound: knowledge and understanding require more than understanding the grammar of a sentence; instead, the student needs to have an intellectual framework about the question in play and an active inquiring mental curiosity in terms of which he or she "thinks" the idea for herself. I do not understand entropy if I simply parrot the definition of the word; rather, I need a framework of ideas about gases, random motion, kinetic energy, and statistical mechanics within the context of which I can give "entropy" a conceptual place.

Anyone who teaches philosophy to undergraduates must be especially receptive to this challenge. The task, somehow, is to help the student make the problem her own -- to see why it is perplexing, to want to dig into it, to be eager to discover new angles on it, to see how it relates to other complicated issues. So in teaching Kant or Arendt, the goal is not to get the student to memorize the list of the antinomies of reason or the three versions of the categorical imperative, or precisely what is meant by "the banality of evil". Rather, it is to help the student to discover the problem that Kant or Arendt was grappling with, why it was important, why it is difficult, and maybe how it can be solved in a different way. 

The student needs somehow to put himself or herself into the mindset of a person on a journey of discovery, creating his or her own conceptual structures and questions about the terrain, without falling into the complacency of thinking she is simply a tourist with an excellent guide. And, after all, if there is nothing new to think about Aristotle or Nussbaum, then what is the purpose of studying them in the first place? Why would it matter to a student that she has read the Nichomachean Ethics cover to cover if she hasn't somehow been stimulated through her own efforts of imagination and discovery to think new and original thoughts?

This insight into the learning process is evident in philosophy, but surely it must be essentially the same kind of challenge in teaching literature, sociological theory, thermodynamics, or even advanced accounting. When I read Stephen Greenblatt on Shakespeare -- or when I hear him lecture on "racial memory" of Vilnius -- I am stimulated to new thinking, new ideas of my own, and a striking lack of interest on Greenblatt's part in being an "authority". Greenblatt somehow succeeds in creating a Dewey-like learning environment, both in his writing and in his teaching.

The past year of teaching courses in a synchronous hybrid online mode, preparing lectures for asynchronous use and using Zoom meetings for class discussions, has brought this set of challenges to the top of mind for me. What kinds of "prompts", questions, topics for discussion, and asynchronous exercises can I use to help students in these courses develop the appetite for taking the intellectual journey themselves? And how can the instructor help the student see that this is an activity of imagination and thinking that she herself wants to involve herself in? How can the instructor help the student to shift perspective from "learning the content of a course about Greek ethics from the professor" to "working my way through some fascinating texts in Greek ethics, seeing some new perspectives, and getting occasional stimulating questions from my professor"? The first is the tourist's perspective, while the second is the explorer's perspective.

In a way, we might say that the role of the teacher that Dewey describes is like that performed by Socrates: posing questions -- perhaps irritating and persistent questions -- but provoking those around him to think much harder about "justice", "piety", and "good manners", and not providing a substantive doctrine of his own. Socrates was sometimes criticized for suggesting that no substantive beliefs about morality could be justified, but that was not his pedagogy. Rather, his commitment was to the idea of hard thinking without pat answers. And one would like to imagine that some of his students eventually came to develop rich, imaginative, and non-dogmatic minds that allowed them to probe new questions and create new solutions. (It is interesting to reflect that Plato was one of those students, and Aristotle was a student of Plato. I think historians of philosophy would judge that both Plato and Aristotle were highly original thinkers, but that Plato's approach was somewhat more dogmatic, while Aristotle's was more open-minded and experimental.)