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<!--[[Image:Aeolipile illustration.JPG|thumb|right|140px|Hero's [[aeolipile]], a simple steam engine]]-->
<!--[[Image:Aeolipile illustration.JPG|thumb|right|140px|Hero's [[aeolipile]], a simple steam engine]]-->
'''Hero''' (or '''Heron''') '''of Alexandria''' ([[Greek language|Greek]]: Ήρων ο Αλεξανδρεύς) (c. [[10]] – [[70]] AD) was a [[Greek mathematics|Greek mathematician]]<ref name=Britannica>Enc. Britannica 2007, "Heron of Alexandria"</ref> and engineer who flourished in [[Alexandria]], [[Ægyptus|Roman Egypt]].
'''Hero''' (or '''Heron''') '''of Alexandria''' ([[Greek language|Greek]]: Ήρων ο Αλεξανδρεύς) (c. [[10]] – [[70]] AD) was a [[mathematician]] and [[engineer]] who flourished in [[Alexandria]], [[Ægyptus|Roman Egypt]]. Most scholars consider him to have been a [[Greeks|Greek]],<ref name=Britannica>Enc. Britannica 2007, "Heron of Alexandria"</ref><ref name="Boyer page 171-172"/> though some consider him [[Egyptians|Egyptian]].<ref name=Katz/><ref name=Sarton/>


Among his most famous inventions were the first documented [[steam engine|steam-powered device]], the ''[[aeolipile]]'', and a [[windmill|windwheel]], constituting one the earliest instances of wind harnessing.<ref name="Drachmann"/><ref name="Lohrmann 10f."/> He is said to have been a follower of the [[atomism|Atomists]]. Some of his ideas were derived from the works of [[Ctesibius]].
Among his most famous inventions were the first documented [[steam engine|steam-powered device]], the ''[[aeolipile]]'', and a [[windmill|windwheel]], constituting one the earliest instances of wind harnessing.<ref name="Drachmann"/><ref name="Lohrmann 10f."/> He is said to have been a follower of the [[atomism|Atomists]]. Some of his ideas were derived from the works of [[Ctesibius]].


== Background ==
== Background ==
His ethnic background was not recorded in ancient times, but scholars believe him to either have been a [[Ancient Greece|Greek]],<ref name= Tokaty >{{cite book | title = A History and Philosophy of Fluid Mechanics | author = Gregory A Tokaty | publisher = Courier Dover Publications | year = 1994 | isbn = 0486681033 | pages = p.26 }}</ref><ref name= Grolier >{{cite book | title = Academic American Encyclopedia | author = Grolier Incorporated | publisher = Grolier [[University of Michigan]] | year = 1989 | isbn = 0717220249 | pages = p.144 }}</ref><ref>[http://www.britannica.com/eb/article-9040189/Heron-of-Alexandria/ Encyclopædia Britannica Online - Heron of Alexandria]</ref><ref name= Shatzman >{{cite book | title = Illustrated Encyclopedia of the Classical World | author = Israel Shatzman, Michael Avi-Yonah | publisher = Harper and Row | year = 1975 | isbn = 0060101784 | pages = p.234 }}</ref><ref name=Clements >{{cite book | title =The Picture History of Great Inventors | author =Gillian Clements | publisher = frances lincoln ltd | year =2005 | isbn = 0711216053| pages = p.13 }}</ref> an [[Ancient Egypt|Egyptian]],<ref>John H. Lienhard, ''[[Engines of our Ingenuity]]'', No. 1038: Hero of Alexandria.</ref><ref>T. D. De Marco (1974). "Gas-Turbine Standby-Power Generation for Water-Treatment Plants", ''Journal American Water Works Association'' '''66''' (2), p. 133-138.</ref><ref>Justin E. Wilson (2006). [http://education.uncc.edu/cmste/summer/2006%20History%20of%20Mathematics/Justin1.doc Heron’s Formula], [[University of North Carolina at Charlotte]].</ref>
His ethnic background was not recorded in ancient times, but scholars believe him to either have been a [[Ancient Greece|Greek]],<ref name= Tokaty >{{cite book | title = A History and Philosophy of Fluid Mechanics | author = Gregory A Tokaty | publisher = Courier Dover Publications | year = 1994 | isbn = 0486681033 | pages = p.26 }}</ref><ref name= Grolier >{{cite book | title = Academic American Encyclopedia | author = Grolier Incorporated | publisher = Grolier [[University of Michigan]] | year = 1989 | isbn = 0717220249 | pages = p.144 }}</ref><ref>[http://www.britannica.com/eb/article-9040189/Heron-of-Alexandria/ Encyclopædia Britannica Online - Heron of Alexandria]</ref><ref name= Shatzman >{{cite book | title = Illustrated Encyclopedia of the Classical World | author = Israel Shatzman, Michael Avi-Yonah | publisher = Harper and Row | year = 1975 | isbn = 0060101784 | pages = p.234 }}</ref><ref name=Clements >{{cite book | title =The Picture History of Great Inventors | author =Gillian Clements | publisher = frances lincoln ltd | year =2005 | isbn = 0711216053| pages = p.13 }}</ref> an [[Ancient Egypt|Egyptian]],<ref name=Sarton>[[George Sarton]] (1936). "The Unity and Diversity of the Mediterranean World", ''Osiris'' '''2''', p. 406-463 [429].</ref><ref>John H. Lienhard, ''[[Engines of our Ingenuity]]'', No. 1038: Hero of Alexandria.</ref><ref>T. D. De Marco (1974). "Gas-Turbine Standby-Power Generation for Water-Treatment Plants", ''Journal American Water Works Association'' '''66''' (2), p. 133-138.</ref>
or possibly even a [[Phoenicia]]n. The historian [[Carl Benjamin Boyer|Boyer]] explains that Hero's identification as an Egyptian or a Phoenician was largely due to the strong [[Babylonia]]n influence on his work and that it is currently generally accepted by historians that Hero was a Greek,<ref name="Boyer page 171-172">{{cite book|last=Boyer|authorlink=Carl Benjamin Boyer|title=|year=1991|chapter=Greek Trigonometry and Mensuration|pages=171-172|quote=At least from the days of Alexander the Great to the close of the classical world, there undoubtedly was much intercommunication between Greece and Mesopotamia, and it seems to be clear that the Babylonian arithmetic and algebraic geometry continued to exert considerable influence in the Hellenistic world. This aspect of mathematics, for example, appears so strongly in Heron of Alexandria (fl. ca. A.D. 100) that Heron once was thought to be Egyptian or Phoenician rather than Greek. Now it is thought that Heron portrays a type of mathematics that had long been present in Greece but does not find a representative among the great figures - except perhaps as betrayed by Ptolemy in the ''Tetrabiblos''.}}</ref> though others still consider it very likely that he could have been Egyptian, or at least a mix of Greek and Egyptian.<ref>Victor J. Katz (1998). ''A History of Mathematics: An Introduction'', "Mathematical Methods in Hellenistic Times". Addison Wesley. ISBN 0321016181.</ref>
or possibly even a [[Phoenicia]]n. [[Carl Benjamin Boyer]] writes that Hero's identification as an Egyptian or a Phoenician was largely due to the strong [[Babylonia]]n influence on his work and that the current consensus is that Hero was a Greek,<ref name="Boyer page 171-172">{{cite book|last=Boyer|authorlink=Carl Benjamin Boyer|title=A History of Mathematics|year=1968 [1991]|chapter=Greek Trigonometry and Mensuration|pages=171-172|quote=At least from the days of Alexander the Great to the close of the classical world, there undoubtedly was much intercommunication between Greece and Mesopotamia, and it seems to be clear that the Babylonian arithmetic and algebraic geometry continued to exert considerable influence in the Hellenistic world. This aspect of mathematics, for example, appears so strongly in Heron of Alexandria (fl. ca. A.D. 100) that Heron once was thought to be Egyptian or Phoenician rather than Greek. Now it is thought that Heron portrays a type of mathematics that had long been present in Greece but does not find a representative among the great figures - except perhaps as betrayed by Ptolemy in the ''Tetrabiblos''.}}</ref> though some still consider it very likely that he could have been Egyptian, or possibly a mix of Greek and Egyptian.<ref name=Katz>Victor J. Katz (1998). ''A History of Mathematics: An Introduction'', "Mathematical Methods in Hellenistic Times". Addison Wesley. ISBN 0321016181.</ref><ref>Justin E. Wilson (2006). [http://education.uncc.edu/cmste/summer/2006%20History%20of%20Mathematics/Justin1.doc Heron’s Formula], [[University of North Carolina at Charlotte]].</ref>


== Career ==
== Career ==
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[[Category:Hellenistic Egyptians]]
[[Category:Hellenistic Egyptians]]
[[Category:Egyptian mathematicians]]
[[Category:Egyptian mathematicians]]
[[Category:Egyptian engineers]]
[[Category:Ancient Greek mathematicians]]
[[Category:Ancient Greek mathematicians]]
[[Category:Ancient Greek inventors]]
[[Category:Ancient Greek inventors]]

Revision as of 13:33, 26 August 2007

Heron
Bornfl. 10 AD
NationalityGreek
Known foraeolipile
Scientific career
FieldsMathematics

Hero (or Heron) of Alexandria (Greek: Ήρων ο Αλεξανδρεύς) (c. 10 – 70 AD) was a mathematician and engineer who flourished in Alexandria, Roman Egypt. Most scholars consider him to have been a Greek,[1][2] though some consider him Egyptian.[3][4]

Among his most famous inventions were the first documented steam-powered device, the aeolipile, and a windwheel, constituting one the earliest instances of wind harnessing.[5][6] He is said to have been a follower of the Atomists. Some of his ideas were derived from the works of Ctesibius.

Background

His ethnic background was not recorded in ancient times, but scholars believe him to either have been a Greek,[7][8][9][10][11] an Egyptian,[4][12][13] or possibly even a Phoenician. Carl Benjamin Boyer writes that Hero's identification as an Egyptian or a Phoenician was largely due to the strong Babylonian influence on his work and that the current consensus is that Hero was a Greek,[2] though some still consider it very likely that he could have been Egyptian, or possibly a mix of Greek and Egyptian.[3][14]

Career

A number of references mention dates around 150 BC, but these are inconsistent with the dates of his publications and inventions. This may be due to a misinterpretation of the phrase "first century" or because Hero was a common name.

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 20th century, it is thought that the work of Hero, his "programmable" automated devices in particular, represents some of the first formal research into cybernetics.[15]

Hero was known for his amazing mechanical ingenuity in the ancient world, to include his contributions in military technology and theatre. He also created devices used in temples to instill faith by deceiving believers with "magical acts of the gods."

Projects

Hero's wind-powered organ (reconstruction)
  • The aeolipile (50/62/70) - the first recorded steam engine (known as Hero's engine) which was created almost two millennia before the industrial revolution, which was powered by steam engines. Apparently Hero's steam engine was taken to be no more than a toy, and thus its full potential not realized for centuries.
  • 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.
  • A windwheel operating an organ, marking probably the first instance of wind powering a machine in history.[5] [6]
  • 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.
  • 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, including any number of reflections on plane surfaces, the path-length followed is the shortest possible. Fifteen centuries later, this principle was generalized by Fermat to include the case of refraction at the interface of two different media, and was expressed in the statement that the time taken by the light ray is minimal as compared with neighbouring paths.

Bibliography

Works known to be of Hero's hand:

  • Pneumatica, a description of machines working on air, steam or water pressure, including the hydraulis or water organ.[16]
  • 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 Automata.
  • Mechanica, 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. In this work the odometer is described, and also an apparatus which resembles a theodolite.
  • Belopoeica, a description of war machines.
  • Catoptrica, about the progression of light, reflection and the use of mirrors.

Works which have sometimes been attributed to Hero, but are now thought to have most likely been written by someone else:[17]

  • Geometria, 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.
  • Cheirobalistra, about catapults.
  • Definitiones, containing definitions of terms for geometry.

Media

A 2007 The History Channel television show Ancient Discoveries includes recreations of most of Hero's devices.

See also

References

  1. ^ Enc. Britannica 2007, "Heron of Alexandria"
  2. ^ a b Boyer (1968 [1991]). "Greek Trigonometry and Mensuration". A History of Mathematics. pp. 171–172. At least from the days of Alexander the Great to the close of the classical world, there undoubtedly was much intercommunication between Greece and Mesopotamia, and it seems to be clear that the Babylonian arithmetic and algebraic geometry continued to exert considerable influence in the Hellenistic world. This aspect of mathematics, for example, appears so strongly in Heron of Alexandria (fl. ca. A.D. 100) that Heron once was thought to be Egyptian or Phoenician rather than Greek. Now it is thought that Heron portrays a type of mathematics that had long been present in Greece but does not find a representative among the great figures - except perhaps as betrayed by Ptolemy in the Tetrabiblos. {{cite book}}: Check date values in: |year= (help)
  3. ^ a b Victor J. Katz (1998). A History of Mathematics: An Introduction, "Mathematical Methods in Hellenistic Times". Addison Wesley. ISBN 0321016181.
  4. ^ a b George Sarton (1936). "The Unity and Diversity of the Mediterranean World", Osiris 2, p. 406-463 [429].
  5. ^ a b A.G. Drachmann, "Heron's Windmill", Centaurus, 7 (1961), pp. 145-151
  6. ^ a b Dietrich Lohrmann, "Von der östlichen zur westlichen Windmühle", Archiv für Kulturgeschichte, Vol. 77, Issue 1 (1995), pp.1-30 (10f.)
  7. ^ Gregory A Tokaty (1994). A History and Philosophy of Fluid Mechanics. Courier Dover Publications. pp. p.26. ISBN 0486681033. {{cite book}}: |pages= has extra text (help)
  8. ^ Grolier Incorporated (1989). Academic American Encyclopedia. Grolier University of Michigan. pp. p.144. ISBN 0717220249. {{cite book}}: |pages= has extra text (help)
  9. ^ Encyclopædia Britannica Online - Heron of Alexandria
  10. ^ Israel Shatzman, Michael Avi-Yonah (1975). Illustrated Encyclopedia of the Classical World. Harper and Row. pp. p.234. ISBN 0060101784. {{cite book}}: |pages= has extra text (help)
  11. ^ Gillian Clements (2005). The Picture History of Great Inventors. frances lincoln ltd. pp. p.13. ISBN 0711216053. {{cite book}}: |pages= has extra text (help)
  12. ^ John H. Lienhard, Engines of our Ingenuity, No. 1038: Hero of Alexandria.
  13. ^ T. D. De Marco (1974). "Gas-Turbine Standby-Power Generation for Water-Treatment Plants", Journal American Water Works Association 66 (2), p. 133-138.
  14. ^ Justin E. Wilson (2006). Heron’s Formula, University of North Carolina at Charlotte.
  15. ^ 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.
  16. ^ Sadie, Stanley; Tyrrell, John, eds. (2001). The New Grove Dictionary of Music and Musicians (2nd ed.). London: Macmillan Publishers. ISBN 978-1-56159-239-5. {{cite encyclopedia}}: Missing or empty |title= (help)‎
  17. ^ O'Connor, J.J. and E.F. Robertson. "Heron biography". The MacTutor History of Mathematics archive. Retrieved 2006-06-18. {{cite web}}: Cite has empty unknown parameter: |1= (help)
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