The Info List - Hero Of Alexandria

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Hero of Alexandria
(/ˈhɪəroʊ/; Greek: Ἥρων[1] ὁ Ἀλεξανδρεύς, Heron ho Alexandreus; also known as Heron of Alexandria
/ˈhɛrən/; c. 10 AD – c. 70 AD) was a mathematician and engineer who was active in his native city of Alexandria, Roman Egypt. He is considered the greatest experimenter of antiquity[2] and his work is representative of the Hellenistic scientific tradition.[3] Hero published a well recognized description of a steam-powered device called an aeolipile (sometimes called a "Hero engine"). Among his most famous inventions was a windwheel, constituting the earliest instance of wind harnessing on land.[4][5] He is said to have been a follower of the atomists. Some of his ideas were derived from the works of Ctesibius. Much of Hero's original writings and designs have been lost, but some of his works were preserved in Arabic manuscripts.


1 Life and career 2 Inventions 3 Mathematics 4 Cultural references 5 Bibliography 6 See also 7 References 8 Further reading 9 External links

Life and career[edit] Hero may have been either a Greek[2] or a Hellenized Egyptian.[6][7][8][9][10] It is almost certain that Hero taught at the Musaeum
which included the famous Library of Alexandria, because most of his writings appear as lecture notes for courses in mathematics, mechanics, physics, and pneumatics. Although the field was not formalized until the twentieth century, it is thought that the work of Hero, his automated devices in particular, represents some of the first formal research into cybernetics.[11] Inventions[edit]

Hero's aeolipile

Hero described[12] the construction of the aeolipile (a version of which is known as Hero's engine) which was a rocket-like reaction engine and the first-recorded steam engine (although Vitruvius mentioned the aeolipile in De Architectura
De Architectura
some 100 years earlier than Hero). It was created almost two millennia before the industrial revolution. Another engine used air from a closed chamber heated by an altar fire to displace water from a sealed vessel; the water was collected and its weight, pulling on a rope, opened temple doors.[13] Some historians have conflated the two inventions to assert that the aeolipile was capable of useful work.[14]

Hero's wind-powered organ (reconstruction)

The first vending machine was also one of his constructions; when a coin was introduced via a slot on the top of the machine, a set amount of holy water was dispensed. This was included in his list of inventions in his book Mechanics
and Optics. When the coin was deposited, it fell upon a pan attached to a lever. The lever opened up a valve which let some water flow out. The pan continued to tilt with the weight of the coin until it fell off, at which point a counter-weight would snap the lever back up and turn off the valve.[15] A windwheel operating an organ, marking the first instance in history of wind powering a machine.[4][5] Hero also invented many mechanisms for the Greek theater, including an entirely mechanical play almost ten minutes in length, powered by a binary-like system of ropes, knots, and simple machines operated by a rotating cylindrical cogwheel. The sound of thunder was produced by the mechanically-timed dropping of metal balls onto a hidden drum. The force pump was widely used in the Roman world, and one application was in a fire-engine. A syringe-like device was described by Hero to control the delivery of air or liquids.[16] In optics, Hero formulated the principle of the shortest path of light: If a ray of light propagates from point A to point B within the same medium, the path-length followed is the shortest possible. It was nearly 1000 years later that Alhacen
expanded the principle to both reflection and refraction, and the principle was later stated in this form by Pierre de Fermat
Pierre de Fermat
in 1662; the most modern form is that the path is at an extremum. A standalone fountain that operates under self-contained hydrostatic energy (Hero's fountain) A programmable cart that was powered by a falling weight. The "program" consisted of strings wrapped around the drive axle.[17]

Mathematics[edit] Hero described a method for iteratively computing the square root of a number.[18] Today, however, his name is most closely associated with Hero's formula
Hero's formula
for finding the area of a triangle from its side lengths. He also devised a method for calculating cube roots in the 1st century CE.[19] Cultural references[edit]

A 1979 Soviet animated short film focuses on Hero's invention of the aeolipile, showing him as a plain craftsman who invented the turbine accidentally[20] A 2007 The History Channel television show Ancient Discoveries includes recreations of most of Hero's devices A 2010 The History Channel television show Ancient Aliens
Ancient Aliens
episode "Alien Tech" includes discussion of Hero's steam engine A 2014 The History Channel television show Ancient Impossible episode "Ancient Einstein" Paul Levinson's Science Fiction
Science Fiction
novel "The Plot to Save Socrates" asserts that Hero was an American time traveler.


The book About automata by Hero of Alexandria
(1589 edition)

The most comprehensive edition of Hero's works was published in five volumes in Leipzig by the publishing house Teubner in 1903. Works known to have been written by Hero:

Pneumatica (Πνευματικά), a description of machines working on air, steam or water pressure, including the hydraulis or water organ[21] Automata, a description of machines which enable wonders in temples by mechanical or pneumatical means (e.g. automatic opening or closing of temple doors, statues that pour wine, etc.); See Automaton
and Bernardino Baldi's translation[22] Mechanica, preserved only in Arabic, written for architects, containing means to lift heavy objects Metrica, a description of how to calculate surfaces and volumes of diverse objects On the Dioptra, a collection of methods to measure lengths, a work in which the odometer and the dioptra, an apparatus which resembles the theodolite, are described Belopoeica, a description of war machines Catoptrica, about the progression of light, reflection and the use of mirrors

Works that sometimes have been attributed to Hero, but are now thought most likely to have been written by someone else:[23]

Geometrica, a collection of equations based on the first chapter of Metrica Stereometrica, examples of three-dimensional calculations based on the second chapter of Metrica Mensurae, tools which can be used to conduct measurements based on Stereometrica and Metrica Cheiroballistra, about catapults Definitiones, containing definitions of terms for geometry

Works that are preserved only in fragments:

Geodesia Geoponica

See also[edit]

Heronian triangle Heronian mean


^ Genitive: Ἥρωνος. ^ a b Research Machines plc. (2004). The Hutchinson dictionary of scientific biography. Abingdon, Oxon: Helicon Publishing. p. 546. Hero of Alexandria
(lived c. AD 60) Greek mathematician and engineer, the greatest experimentalist of antiquity  ^ Marie Boas, "Hero's Pneumatica: A Study of Its Transmission and Influence", Isis, Vol. 40, No. 1 (Feb., 1949), p. 38 and supra ^ a b A.G. Drachmann, "Heron's Windmill", Centaurus, 7 (1961), pp. 145–151 ^ a b Dietrich Lohrmann, "Von der östlichen zur westlichen Windmühle", Archiv für Kulturgeschichte, Vol. 77, Issue 1 (1995), pp. 1–30 (10f.) ^ George Sarton (1936). "The Unity and Diversity of the Mediterranean World", Osiris 2, p. 406-463 [429] ^ John H. Lienhard (1995). "Hero of Alexandria". The Engines of Our Ingenuity. Episode 1038. NPR. KUHF-FM Houston.  ^ T. D. De Marco (1974). "Gas- Turbine
Standby-Power Generation for Water-Treatment Plants", Journal American Water
Works Association 66 (2), p. 133-138. ^ Justin E. Wilson (2006). Heron’s Formula Archived 2009-03-26 at the Wayback Machine., University of North Carolina at Charlotte. ^ Victor J. Katz (1998). A History of Mathematics: An Introduction, p. 184. Addison Wesley, ISBN 0-321-01618-1: "But what we really want to know is to what extent the Alexandrian mathematicians of the period from the first to the fifth centuries C.E. were Greek. Certainly, all of them wrote in Greek and were part of the Greek intellectual community of Alexandria. And most modern studies conclude that the Greek community coexisted [...] So should we assume that Ptolemy
and Diophantus, Pappus and Hypatia
were ethnically Greek, that their ancestors had come from Greece at some point in the past but had remained effectively isolated from the Egyptians? It is, of course, impossible to answer this question definitively. But research in papyri dating from the early centuries of the common era demonstrates that a significant amount of intermarriage took place between the Greek and Egyptian communities [...] And it is known that Greek marriage contracts increasingly came to resemble Egyptian ones. In addition, even from the founding of Alexandria, small numbers of Egyptians
were admitted to the privileged classes in the city to fulfill numerous civic roles. Of course, it was essential in such cases for the Egyptians
to become "Hellenized," to adopt Greek habits and the Greek language. Given that the Alexandrian mathematicians mentioned here were active several hundred years after the founding of the city, it would seem at least equally possible that they were ethnically Egyptian as that they remained ethnically Greek. In any case, it is unreasonable to portray them with purely European features when no physical descriptions exist." ^ Kelly, Kevin (1994). Out of control: the new biology of machines, social systems and the economic world. Boston: Addison-Wesley. ISBN 0-201-48340-8.  ^ Hero (1899). "Pneumatika, Book ΙΙ, Chapter XI". Herons von Alexandria
Druckwerke und Automatentheater (in Greek and German). Wilhelm Schmidt (translator). Leipzig: B.G. Teubner. pp. 228–232.  ^ Hero of Alexandria
(1851). "Temple Doors opened by Fire on an Altar". Pneumatics
of Hero of Alexandria. Bennet Woodcroft (trans.). London: Taylor Walton and Maberly (online edition from University of Rochester, Rochester, NY). Archived from the original on 2008-05-09. Retrieved 2008-04-23.  ^ For example: Mokyr, Joel (2001). Twenty-five centuries of technological change. London: Routledge. p. 11. ISBN 0-415-26931-8. Among the devices credited to Hero are the aeolipile, a working steam engine used to open temple doors  and Wood, Chris M.; McDonald, D. Gordon (1997). "History of propulsion devices and turbo machines". Global Warming. Cambridge, England: Cambridge University Press. p. 3. ISBN 0-521-49532-6. Two exhaust nozzles...were used to direct the steam with high velocity and rotate the sphere...By attaching ropes to the axial shaft Hero used the developed power to perform tasks such as opening temple doors  ^ Humphrey, John W.; John P. Oleson; Andrew N. Sherwood (1998). Greek and Roman technology: A Sourcebook. Annotated translations of Greek and Latin texts and documents. Routledge Sourcebooks for the Ancient World. London and New York: Routledge. ISBN 978-0-415-06137-7. , pp. 66–67 ^ Woodcroft, Bennet (1851). The Pneumatics
of Hero of Alexandria. London: Taylor Walton and Maberly. Retrieved January 27, 2010. No. 57. Description of a Syringe [permanent dead link] ^

Noel Sharkey (July 4, 2007), A programmable robot from AD 60, 2611, New Scientist  The above citation embeds a video using Flash Player, which fewer devices support over time. The same video is also available at this URL: https://www.youtube.com/watch?v=xyQIo9iS_z0

^ Heath, Thomas (1921). A History of Greek Mathematics, Vol. 2. Oxford: Clarendon Press. pp. 323–324.  ^ Smyly, J. Gilbart (1920). "Heron's Formula for Cube Root". Hermathena. Trinity College Dublin. 19 (42): 64–67. JSTOR 23037103.  ^ animator.ru ^ Jamies W. McKinnon. "Hero of Alexandria
and Hydraulis". In L. Root, Deane. Grove Music Online. Oxford Music Online. Oxford University Press.  (subscription required) ^ De gli automati, overo machine se moventi, Volume
2 (Venice, 1589; repr. 1601), On Automaton; translated from the Greek. ^ O'Connor, J.J. & E.F. Robertson. "Heron biography". The MacTutor History of Mathematics
archive. Retrieved 2006-06-18. 

Further reading[edit]

Drachmann, Aage Gerhardt (1963). The Mechanical Technology of Greek and Roman Antiquity: A Study of the Literary Sources. Madison, WI: University of Wisconsin Press.  Landels, J.G. (2000). Engineering in the ancient world (2nd ed.). Berkeley: University of California Press. ISBN 0-520-22782-4.  Marsden, E.W. (1969). Greek and Roman Artillery: Technical Treatises. Oxford: Clarendon Press.  Schellenberg, H.M.: Anmerkungen zu Hero von Alexandria
und seinem Werk über den Geschützbau, in: Schellenberg, H.M./ Hirschmann, V.E./ Krieckhaus, A.(edd.): A Roman Miscellany. Essays in Honour of Anthony R. Birley on his Seventieth Birthday, Gdansk 2008, 92-130 (with a huge bibliography of over 300 titles and discussion of the communis opinio on Hero).

External links[edit]

Wikimedia Commons has media related to Hero of Alexandria.

Greek Wikisource
has original text related to this article: Ἥρων ὁ Ἀλεξανδρεύς

has the text of the 1911 Encyclopædia Britannica
Encyclopædia Britannica
article Hero of Alexandria.

Webpage about Hero by The Technology Museum of Thessaloniki A translation of Pneumatica with diagrams Heron biography, The MacTutor History of Mathematics
archive Hero of Alexandria
in the 1911 Encyclopædia Britannica Heron of Alexandria
in online Encyclopædia Britannica Online Galleries, History of Science Collections, University of Oklahoma Libraries High resolution images preserved at The Internet Archive  "Hero of Alexandria". New International Encyclopedia. 1905.  Reconstruction of Heron’s Formulas for Calculating the Volume
of Vessels Spiritali di Herone Alessandrino From the John Davis Batchelder Collection at the Library of Congress The Pneumatics
of Hero of Alexandria, from the Original Greek. Tr. and ed. by Bennet Woodcroft From the Collections at the Library of Congress

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Ancient Greek mathematics


Anaxagoras Anthemius Archytas Aristaeus the Elder Aristarchus Apollonius Archimedes Autolycus Bion Bryson Callippus Carpus Chrysippus Cleomedes Conon Ctesibius Democritus Dicaearchus Diocles Diophantus Dinostratus Dionysodorus Domninus Eratosthenes Eudemus Euclid Eudoxus Eutocius Geminus Heron Hipparchus Hippasus Hippias Hippocrates Hypatia Hypsicles Isidore of Miletus Leon Marinus Menaechmus Menelaus Metrodorus Nicomachus Nicomedes Nicoteles Oenopides Pappus Perseus Philolaus Philon Porphyry Posidonius Proclus Ptolemy Pythagoras Serenus Simplicius Sosigenes Sporus Thales Theaetetus Theano Theodorus Theodosius Theon of Alexandria Theon of Smyrna Thymaridas Xenocrates Zeno of Elea Zeno of Sidon Zenodorus


Almagest Archimedes
Palimpsest Arithmetica Conics (Apollonius) Elements (Euclid) On the Sizes and Distances (Aristarchus) On Sizes and Distances
On Sizes and Distances
(Hipparchus) On the Moving Sphere (Autolycus) The Sand Reckoner


Problem of Apollonius Squaring the circle Doubling the cube Angle trisection


Cyrene Library of Alexandria Platonic Academy

Timeline of Ancient Greek mathematicians

Authority control

WorldCat Identities VIAF: 22944086 LCCN: n81055336 ISNI: 0000 0001 0797 9256 GND: 119107430 SELIBR: 288241 SUDOC: 029539722 BNF: cb121144764 (data) NDL: 00543