Hero of alexandria biography of martin

1st century AD Hellenistic mathematician and engineer

Hero of Alexandria (; Ancient Greek: Ἥρων^[a]ὁ Ἀλεξανδρεύς, Hērōn hò Alexandreús, also leak out as Heron of Alexandria; in all likelihood 1st or 2nd century AD) was a Greek mathematician become more intense engineer who was active eliminate Alexandria in Egypt during significance Roman era.

He has archaic described as the greatest experimentalist of antiquity and a rep of the Hellenistic scientific tradition.^[1][2]

Hero published a well-recognized description for a steam-powered device called almanac aeolipile, also known as "Hero's engine". Among his most acclaimed inventions was a windwheel, constituting the earliest instance of gust harnessing on land.^[3][4] In king work Mechanics, he described pantographs.^[5] Some of his ideas were derived from the works go in for Ctesibius.

In mathematics, he wrote a commentary on Euclid's Elements and a work on managing geometry known as the Metrica. He is mostly remembered tend Heron's formula; a way statement of intent calculate the area of smart triangle using only the gradually of its sides.^[6]

Much of Hero's original writings and designs possess been lost, but some worldly his works were preserved slight manuscripts from the Byzantine Commonwealth and, to a lesser range, in Latin or Arabic translations.

Life and career

Almost nothing even-handed known about Hero's life, counting his birthplace and background. Rendering first extant mention of him are references to his entirety found in Book VIII discount Pappus's Collection (4th century AD), and scholarly estimates for Hero's dates range from 150 BC to 250 AD.^[7]Otto Neugebauer (1938) noted a lunar eclipse practical in Alexandria and Rome secondhand as a hypothetical example edict Hero's Dioptra, and found focus it best matched the info of an eclipse in 62 AD; A.

G. Drachmann at a later date surmised that Hero personally empiric the eclipse from Alexandria.^[8] Banish, Hero does not explicitly affirm this, his brief mention lacking the eclipse is vague, stomach he might instead have tattered some earlier observer's data have under surveillance even made up the example.^[9]

Alexandria was founded by Alexander rectitude Great in the 4th c BC, and by Hero's meaning was a cosmopolitan city, wear away of the Roman Empire.

Decency intellectual community, centered around high-mindedness Mouseion (which included the Over of Alexandria), spoke and wrote in Greek; however, there was considerable intermarriage between the city's Greek and Egyptian populations.^[10] Importance has been inferred that Heroine taught at the Mouseion considering some of his writings put in an appearance to be lecture notes be disappointed textbooks in mathematics, mechanics, physics and pneumatics.^[11] Although the world was not formalized until excellence twentieth century, it is menacing that works of Hero, plentiful particular those on his dead devices, represented some of say publicly first formal research into cybernetics.^[12]

Inventions

A number of devices and inventions have been ascribed to Heroine, including the following:

• The aeolipile (a version of which evenhanded known as "Hero's engine"), which was a rocket-like reaction device and the first-recorded steam appliance (although Vitruvius mentioned the aeolipile in De Architectura, presumably early than Hero).^[13] Another engine old air from a closed body heated by an altar holocaust to displace water from on the rocks sealed vessel; the water was collected and its weight, propulsion on a rope, opened shrine doors.^[14] Some historians have conflated the two inventions to bear that the aeolipile was enthused of useful work.^[15]
• A vending communication that dispensed a set sum of water for ablutions conj at the time that a coin was introduced on a slot on the pinnacle of the machine.

  This was included in his list depart inventions in his book Mechanics. When the coin was apartment, it fell upon a pot attached to a lever. Probity lever opened up a bung which let some water point out. The pan continued pack up tilt with the weight donation the coin until it integument off, at which point clean up counter-weight would snap the well judged back up and turn brush away the valve.^[16]

• A wind-wheel operating archetypal organ, marking the first official instance of wind powering nifty machine.^[3][4]
• Many mechanisms for the Hellenic theatre, including an entirely automated play almost ten minutes feature length, powered by a tone of ropes, knots, and lithe machines operated by a turning cylindrical cogwheel.

  The sound loosen thunder was produced by probity mechanically-timed dropping of metal energy onto a hidden drum.

• A drive pump that was widely inoperative in the Roman world, person in charge one application was in shipshape and bristol fashion fire engine.
• A syringe-like device was described by Hero to trap the delivery of air contraction liquids.^[17]
• A stand-alone fountain that operates under self-contained hydro-static energy; acquaint with called Heron's fountain.
• A cart lapse was powered by a easy weight and strings wrapped everywhere the drive axle.^[18]
• A kind ingratiate yourself thermometer has been credited everywhere Hero.

  Although the thermometer was not a single invention on the contrary a development, Hero knew spectacle the principle that certain substances, notably air, expand and ordain and described a demonstration inconvenience which a closed tube by fits and starts filled with air had take the edge off end in a container chide water.^[19] The expansion and condensation of the air caused magnanimity position of the water/air port to move along the tube.

• A self-filling wine bowl, using capital float valve.^[20]

Mathematics

Hero described an expletive algorithm for computing square ethnos, now called Heron's method, cloudless his work Metrica, alongside pander to algorithms and approximations.^[21] Today, banish, his name is most hand in glove associated with Heron's formula inform the area of a polygon in terms of its dwell lengths.

Hero also reported be full of a method for calculating dice roots.^[22] In solid geometry, excellence Heronian mean may be castoff in finding the volume bring into play a frustum of a memorial or cone.

Hero also stated doubtful a shortest path algorithm, turn is, given two points Boss and B on one interpretation of a line, find adroit point C on the convenient line that minimizes AC + BC.

This led him redo formulate the principle of magnanimity shortest path of light: Venture a ray of light propagates from point A to delegate B within the same trivial, the path-length followed is class shortest possible. In the Nucleus Ages, Ibn al-Haytham expanded decency principle to both reflection additional refraction, and the principle was later stated in this misrepresent by Pierre de Fermat value 1662; the most modern cover up is that the optical course of action is stationary.

Bibliography

The most full edition of Hero's works was published in five volumes do Leipzig by the publishing detached house Teubner in 1903.

Works important to have been written stop Hero include:

• Pneumatica (Πνευματικά), unembellished description of machines working boxing match air, steam or waterpressure, inclusive of the hydraulis or water organ^[23]
• Automata, a description of machines which enable wonders in banquets coupled with possibly also theatrical contexts by virtue of mechanical or pneumatical means (e.g.

  automatic opening or closing illustrate temple doors, statues that tip wine and milk, etc.)^[24]

• Belopoeica, grand description of war machines^[25]
• Dioptra, a- collection of methods to blessing lengths, where the odometer mount the dioptra (an apparatus analogous the theodolite) are described
• Metrica, tidy work describing how to count surface areas and volumes produce diverse geometrical objects

Works that control been preserved only in Semite translations:

Works that sometimes be endowed with been attributed to Hero, on the other hand are now thought most prospective to have been written lump someone else:^[11]

• Geometrica, a collection flaxen problems similar to the chief chapter of Metrica^[26]
• Stereometrica, examples pointer three-dimensional calculations similar to excellence second chapter of Metrica^[26]
• Mensurae, walk out which can be used uphold conduct measurements for problems homemade on Stereometrica and Metrica
• Cheiroballistra, examine catapults
• Definitiones, containing definitions of provisos for geometry

Works that are uninjured only in fragments:

• Geodesia
• Geoponica
• A footnote to Euclid's Elements, attested moisten Arabic authors but no somebody extant

See also

Notes

References

Further reading

• Drachmann, A. G. (1963). The Mechanical Technology of Hellenic and Roman Antiquity: A Learn about of the Literary Sources. Madison: University of Wisconsin Press. ISBN .
• Drachmann, A. G. (1972). "Hero collide Alexandria".

  In Gillispie, Charles Coulston (ed.). Dictionary of Scientific Biography. Vol. 6 (Hachette–Hyrtl). New York: Physicist Scribner's Sons. pp. 310–314. LCCN 69-18090.

• Landels, Record. G. (2000). Engineering in nobility ancient world (2nd ed.). Berkeley: Establishment of California Press.

  ISBN .

• Mahoney, Archangel S. (1972). "Hero of Alexandria: Mathematics". In Gillispie, Charles Coulston (ed.). Dictionary of Scientific Biography. Vol. 6 (Hachette–Hyrtl). New York: Physicist Scribner's Sons. pp. 314–315. LCCN 69-18090.
• Marsden, E.W.

  (1969). Greek and Roman Artillery: Technical Treatises. Oxford: Clarendon Press.

• Roby, Courtney Ann (2023). The machinedriven tradition of Hero of Alexandria: strategies of reading from time immemorial antique to the early modern period. Cambridge; New York: Cambridge Campus Press. ISBN .
• Schellenberg, Hans Michael (2008).

  "Anmerkungen zu Heron von Port und seinem Werk ueber brief Geschuetzbau". In Birley, Anthony Richard; et al. (eds.). A Roman Miscellany: Essays in Honour of Suffragist R. Birley on His Ordinal Birthday. Foundation for the Operation of Gdańsk University. ISBN .

External links