Heron and his Steam Engine, why was it not developed further?

Michael Lahanas

... For if every instrument could accomplish its own work, obeying or anticipating the will of others, like the statues of Daedalus, or the tripods of Hephaestus, which, says the poet, of their own accord entered the assembly of the Gods; if, in like manner, the shuttle would weave and the plectrum touch the lyre without a hand to guide them, chief workmen would not want servants, nor masters slaves.
Aristotle Politics Chapter 3, Book 1

^The development of technology and science depends on a complex way on socio-politic-economic parameters. Why should Greeks develop a telescope if Prolemy's cosmological model was accurate enough? More likely it would be interesting as an instrument useful for the military (see Galileo). Why should the Athenians adapt the Meton calendar or later more accurate calendars? If you develop one accurate measuring device then sometimes you discover other unexpected effects or phenomena (or other interesting things such as some moons of Jupiter) and to study these you develop other devices. Today we know this and we hope by increasing the capabilities of a device also to expand our knowledge with new discoveries. You need of course some financial support for the development, for the material and the necessary experiments. Ancient Greeks knew that heated air expands, or that the length of a cord as Heron describes changes by humidity, but there was no reason to use this information to produce a device to measure temperature (by the expansion, just by placing a scale) or humidity. The question is how the volume or the length depends on temperature but one can find this with controlled experiments. Such experiments were performed by Greek engineers when they developed the catapults. Recently there was an interesting BBC report of the construction of a giant catapult. Experienced engineers constructed a catapult and after 2-3 shots the catapult was damaged. Engineeers using Laptop computers estimated the range, experiments in modern laboratories were used to find a material that can be used for the storage of energy. They had to lift the heavy parts of the giant catapult with a modern device after they tried to use a device used by the Romans and the experiment failed. The engineers were happy that they were able to use the catapult 2-3 times whereas for the ancient Greeks and Romans it would be a disaster if they had to produce a new catapult after a few shots. The ancient engineers probably reached the physical limits of these devices with wood as material and some maybe metal support.

I was reading the notes of a US professor discussing the reason why technology was not developed for almost 1000 years from 400 to say 1500. We assume that the ancient Greeks were more “theoretical” oriented but devices such as the Antikythera show that this is not the truth. Ptolemy's model even geocentric was accurate enough to describe most of the astronomical events and even Copernicus did not improve its precision but instead he provided more scientific evidence of the heliocentric model of Aristarchus. Various sources are mentioned where Plato or Aristotle think that to ask about the utility of something is bad. Plato is very strict and forbids the use of anything than ruler and compass in geometry, where the ruler actually cannot be used to measure distances as in this case the trisection of an angle is very simple. Is he different from the mathematician Hardy, a number theory expert, who was proud that his science is of no use? Then the professor asks whether the Jew Christian religion was responsible for the later advance of technology. One may ask whether actually the opposite is true, whether the decline of Greek Science in the Roman dominated period was due to the mixing of cultures: The result of occultic Egyptian influences slowly took over the more rational Greeks (even today it is unbelievable that millions read each day their horoscope or think that their zodiac sign matters what they do or what will happen). Later the Romans leaders, Pagans or Christian, did not supporting science like the Ptolemies in Alexandria. I agree that during the Byzantine Empire very nice religious songs were produced and some remarkable churches but I am not aware of any comparable advance in science such as around the period 500-200 BC. Devices like clocks using gears actually were less complicated than the Antikythera device. A very important contribution was that the ancient Greek texts were partially preserved so that if we talk about Greek texts actually we mean Byzantine copies as the originals were all lost. Another important source was the work of the Arabs who copied the Greek texts, translated them and extended these with their own research. So the question is not why the ancient Greeks did not develop technology but rather why the others did not develop further science and technology much before 1500.

The amount of mechanical development will always be in inverse ratio to the number of slaves that happen to be at a country’s disposal.
Van Loon’s Law

Heron of Alexandria invented the use of steam power in 50 AD (steam energy transfer into rotational motion) with a device of small efficiency but could we expect more from the first every build machine of this type? The birthday of Heron is not known and so some consider that he lived around 150 BC but it is more likely that he lived in the period 10-70 AD. Some 200 years before Heron steam power was also used: Archimedes invented a steam operated gun (more than 1500 later called Architronio by Leonardo Da Vinci ) and Philon of Byzantium produced a Siren for the Pharos of Alexandria (he described various devices that work with air or steam). Heron's Aeolipile was the first jet engine, although the principle behind its operation was not fully understood until Isaac Newton's Third Law of motion (1690): "Every action produces a reaction equal in force and opposite in direction." The steam engine reappeared again only in 1698 when Thomas Savery invented a steam pump. The first practical steam engine was the atmospheric machine of Thomas Newcomen in 1701. In 1804, English inventor Richard Trevithick introduced the steam locomotive in Wales. In 1815, George Stephenson built the world's first workable steam locomotive.

It's not so much that slaves were available, which indeed they were. No, the ruling classes were scared, as the Puritans said, of Satan finding work for idle hands to do. One of the great things about not developing a source of energy that did not depend on muscle power was the fear of what the muscles might get up to if they weren't kept fully employed. Peter Green, Hellenistic History and Culture

Why was Hero’s steam turbine developed no farther than a novelty? In 1st century Greece, slaves were an important element of the economy, salves outnumbering freemen by more than two to one and they provided all the work anyone needed. The slave-based economy would have been rocked by the introduction of laborsaving devices and displaced slaves might have caused unrest or even revolution. And, so, the steam engine played a role in entertainment, but not business. Were the Greeks aware about such consequences? We only can speculate about this. But it is reported that in Rome, at about the same time, the emperor Vespasian to have purchased and destroyed the model of a mechanical device that would have made construction work more efficient, saying, “You must let me feed my poor commons (Sine me pascere plebeculam meam)” In these cases, preserving political stability motivated government to suppress technology, but at other times, governments have been motivated to support it.
[If there had been no Manhattan Project] Nuclear physicists would have spent years forming theories and doing experiments while competing with scientists from other fields to get money for their work…[the U.S.] had plenty of coal and oil…[so] the 1990s would have had low-power nuclear reactors operating to produce medical isotopes, but nothing else.
Robert Pool

We think that architects [master craftsmen] in all fields are more honorable and know more and are wiser than the artisans because they understand the reasons for the things done, while the artisans do things, just like some inanimate objects, without knowing how to do the things they do .... Artisans accomplish their work through customs .... As more and more arts [technai] were discovered, some pertaining to necessities and some to pastimes, the inventors of the latter were always considered wiser than the inventors of the former, because their knowledge was not oriented towards utility.”
Metaphysics 981a-982a

The Greeks made a distinction between science and Engineering or technology. Engineers teached their skills to their sons or apprentices who learned more from practice and experience than by reading books. Their skills were generally kept sometimes as "trade secrets" within the artisan group or groups, much as the medieval guilds kept their secrets in later centuries. They did no controlled experiments to understand the nature of the material they used except probably trial and error methods for developing better, cheaper products. The Scientists and Philosophers, were skilled in argument, debate and formal reasoning. The classical logic of hypothesis and syllogism and the logical beauty of Euclidean plane geometry are examples of this turn of mind and culture. The idea of resolving a dispute between theories by experiment rather than by debate would not have occurred to them. Even if it had, the technological ability to do the experiments was often absent; more important, perhaps, was the conceptual problem, because the concepts of their science were not clearly enough defined to suggest experiments that they could have carried out. It would be a mistake, however, to think that the Greeks could not make accurate measurements; they could and did make quite accurate measurements in estimating for example the size of the earth: It is also mistake to consider that they were not skilled in observation as astronomy shows the contrary.

The device of Antikythera, the planetarium, the screw device of Archimedes etc, shows that a more advanced technology could be developed on a broader basis. Archimedes considered his technical devices to be not worthwhile to write about. There is no material written for the planetarium, the screw, and other machines like his war devices. He liked more his geometric-mathematical discoveries. The idealism of Plato and Aristotle were probably a reason that Archimedes did not consider his technical work as important as mathematics and geometry. At least he used methods that were not “conformal” according to Plato.

Plato: Mechanics as corrupter and destroyer of pure excellence of geometry.
Aristotle: To dwell on utility is bad taste.
Plutarch: Archimedes regarded “work of an engineer and every art that ministers to needs of life as ignoble and vulgar”

In the history of Greek science one has to distinguish between two parallel developments: on the one hand scientific achievements in the technical sense, comprising all the factual discoveries and inventions in mathematics, astronomy and the physical and biological sciences, and on the other hand scientific thought, aiming at the formation of comprehensive theories and the philosophical foundation of a scientific world-picture. The development of science proper, taken in the first sense… faded out after the second century AD…. Scientific thought, however, continued… until the last Neo-Platonists in the middle of the sixth century AD. … In ancient Greece the scope of experimental research remained restricted because the Greeks, with very few exceptions, failed to take the decisive step from observation to systematic experimentation. Thus hardly any links were formed between the few branches of science that developed, and they did not expand sufficiently to produce a coherent and interdependent system…. The scientific world-picture of Aristotle… became dominant in Greek and medieval thought. In fact, it is one of the three major world views in the history of science, being followed after a long interval by that of Newton which has since been replaced by that of relativity and quantum physics.
Samuel Sambursky, The physical world of late antiquity, Routledge and Kegan Paul, [1962]
There was some technical advance in the work of Hero later even if some consider it very simplistic. The development of Greek Science was much slower at the Hellenistic period compared to the advances in the 3rd to 2nd BC century. While the expansion of the Greek world due to the campaign of Alexander the Great was impressive it was also the reason of its decline. The mixing of the more rational Greek culture with others more mythical oriented, the sophists the democracy and small city states replaced by huge Empires and Christian religion combined was the reason that only 3 centuries later a new almost 1500 year long dark period started for the Western World.
It is the combination of controlled observation for the purpose of advancing understanding which we call an experiment which is missing from the natural philosophy of the ancient Greeks. The representation of numbers also seems to be a limitation for further mathematical advances. Would the ancient Greeks be able to “discover” experimental science if the conditions would be favorable such as in the golden age of Athens and how much would be technology be advanced today? We will never know.
The opinion is that Greek Science was different than today in that there was no interest in controlling nature. Was religion a reason that we have no industrial revolution, or requires technological revolution some specific elements for its initiation?

Part from

Ancient and Modern Science: Some Observations
Ian Johnston

Greek Science and The Vision of the World

We should not, however, too quickly claim to see the start of everything in the modern enterprise we call science in the activity of these ancient Greek thinkers. For there were some really important differences between the old philosophers and the modern scientific researcher. To begin with, the primary aim of the Greek thinkers was to arrive at a better contemplative understanding of the nature of things. They had no notion of using their speculations as a means of gaining control of nature or of altering the natural conditions of life.

This point is crucial. At its heart, the Greek philosophical interest in mathematical investigations of the natural world was moral and religious. It was motivated above all by the desire to arrive at a higher knowledge of the divine, the permanent ordering principles by which the world, in all its manifestations, was arranged. In a sense, these philosophers saw a rigorous study of mathematics as a process of spiritual cleansing designed to prepare the human mind for the contemplation of the divine purpose (in other words, as an alternative to many irrational religious rituals, myths, and mysteries). This tradition is very much a part of Socrates's entire project (as recorded and interpreted by Plato).

Since the ancient Greeks saw nature as divine, as having a mysteriously vital soul of its own, an essence with which human beings constantly interacted, there could be no question of "changing" nature or seeking in some ways to alter the given facts of life. Such an endeavour would have violated the way these philosophers understood the world. Nature (including the world around them and the cosmos) was a divinely alive mystery which might be intellectually apprehended and contemplated (at least in part). The aim of scientific speculation was to assist in that essentially contemplative exercise.

For that reason, Greek scientists showed no great interest in experimentation and no desire to develop their scientific thinking into practical applications. By the Hellenistic period (the fourth and third centuries BC), for example, Greek scientists knew about all the principles necessary to construct a steam engine. But the notion that they might actually build one and use it to overcome certain natural limitations never occurred to them. Nature was there to be wondered at, contemplated, even worshipped, not to be tampered with or altered.

Moreover, since the mysterious divine powers which were the creative source of everything, including political structures just as much as natural phenomena, were good, a mathematical understanding of the world linked the inquiring spirit of the thinker with the search for the ultimate purposes of things. To such a mind, it was far less important to figure out how things worked than to focus upon what these things might mean in the overall moral arrangement of the universe. Hence, the pursuit of what we might call science was primarily an inquiry into questions of value. A properly disciplined inquiry into nature could lead to a fuller understanding of the moral issues on which questions of justice in the community depended. The practical value of such inquiry was thus primarily moral.

The Four Causes

This major emphasis on value becomes most apparent in the Aristotle's famous explanation of the different causes for all phenomena. If scientific speculation is, in very large part, a search for rational explanations of cause (i.e., for an answer to this question "How did this natural phenomenon come into existence?"), then, according to Aristotle, there were four possible ways of accounting for that cause: the Material Cause, the Efficient Cause, the Formal Cause, and the Final Cause.

The material cause explains the phenomenon in terms of the material out of which it is made; the efficient cause explains the phenomenon in terms of the process which puts the materials together; the formal cause explains the phenomenon in terms of the plan or design or arrangement of the materials; and the final (*) cause explains the phenomenon in terms of its purpose (especially its moral purpose).

(* The original text used the word “formal” and not “final” which is probably a typing error)

So, for example, if we wanted to account for the existence of, say, a house, the material cause would be the wood, nails, glass, concrete, and so on which make up the house; the efficient cause would be the actions of the various workers who constructed it (carpenters, roofers, carpet layers, and so on); the formal cause would be the architectural design and drawings; the final cause would be a moral reason why the house ought to be built at all and why it should look the way it does in the wider context of the community and the world.

The explanations sought by classical science were concerned above all with the final cause, that is, with an account of whatever one was speculating about which placed it in the overall moral scheme of the universe, linking that object or institution with a sense of moral purposiveness and hence with the divine structure of the universe (what Plato and Aristotle call the Good). This was the central purpose in almost all the most important speculations of Greek philosophy about the natural world or about politics, simply because for these thinkers the most challenging fact of life was an ethical concern: knowledge about the world only mattered if it helped people to understand how they ought to behave (i.e., gave them insight into the ultimate standards of morality and justice). Such thinking is called teleological (from the Greek word telos meaning goal), because it seeks explanations for things in terms of their final purposes.

Given this emphasis, it is not difficult to appreciate why ancient Greek science placed little emphasis on experimentation or working with theories which might enable them to manipulate nature (i.e., change some factor in nature). Of course, like all cultures the classical Greeks had a certain technical knowledge, for example, in medicine, metallurgy, pottery, construction (especially of ships), and selective breeding of domestic animals, but it is clear that the philosophers inquiring into nature considered this form of knowledge (which we prize highly as something immediately allied to our scientific endeavours) distinctly inferior. Extending this technical expertise in some way played no role whatsoever in their speculative theories (even though some of them were experts in technical matters, like military defenses and weapons).

I remember the days when I visited my grandmother in Greece, in a small village called magiko or “magic” in Xanthi around 1970 (not far from Abdera the City of Democritus). I traveled by train from Germany to Greece. Moving from the north to the south it was like a travel back in time. I was a witness when her house was for the first time connected with a power-line and electricity was available almost 70 years after Edison made a demonstration of electric light in New York. Before this life in this small Greek village was almost not different than in ancient Greece.

The four causes

The Antikythera Mechanism: Physical and Intellectual Salvage from the 1st Century BC

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