Hero Of Alexandria

Hero (or '''Heron''') '''of Alexandria''' (c. 10 – 70 ) was a Hellenized Egyptian engineer and geometer in Alexandria , Egypt . His most famous invention was the first documented Steam Engine , the '' Aeolipile ''. He is said to have been a follower of the Atomists . Some of his ideas were derived from the works of Ctesibius .

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 a confusion of this Hero with other Heros- Hero was not an uncommon name.

It is also believed that Heron taught at the Museum in Alexandria. This is because most of his writings appear as lecture notes for courses,based in mathematics, mechanics,physics,and pneumatics as well as his publications which appear as textbooks.

PUBLICATIONS

The complete surviving works are

''Pneumatica'' (Greek, c. 60 ),

''Automata'' (Greek),

''Mechanics'' (Arabic),

''Metrics'' (Arabic),

''Dioptra'' (Arabic).

In Optics , Hero proposed that Light travels along the shortest geometric path. This view is no longer accepted, having been replaced by the Least-time Principle .

In Geometry , he stated and proved the result now known as Hero's or Heron's Formula ,
which expresses the area of any triangle in terms of the lengths of its sides:

:

\mathrm{area} = \sqrt{s\left(s-a
ight)\left(s-b
ight)\left(s-c
ight)}\,

where ''s'' is the triangle's semiperimeter:

:

s=rac{a+b+c}{2}

He also came up with an iterative process for calculating Square Root s of numbers.

Hero is credited with inventing many Feedback control devices using water, fire and compressed air in various combinations, and the first type of analogue Computer Programming via intricate systems of geared spindles studded with pegs and wound with ropes connected to weights (trays of sand emptying over time) used to operate his automatic Theater s that included Automatic Door s and multiple changing scenes of moving figures accompanied by lighting and Sound Effect s.

The Pneumatica was a treatise on natural magic, which is considered to be a study on unexplained properties of nature. These unexplained properties, during his time, which he talked about, included steam, water, and air. These were the properties that powered many of his contraptions. In this work, he mentions air being compressible, expanding and contracting. Air is a material substance. In addition, he mentions the existence of vacuums between particles. Pneumatica had a great influence on the revival of hydrodynamics,the study of water motion and fluids. This came about in the sixteenth century when many engineers and scholars became interested in Hero's works. The Pneumatica was the most authoritative source for studies on the properties of air until the works of Pascal, Boyle, Mariotte and others. The air properties mentioned in Pneumatica suggested steam powered engines.

Metrica, discovered in 1896, book 1 covers finding the area of a triangle, Book II covers finding the volume of certain shapes (cylinders,cones, spheres, pyramids) and Book III covers areas and volumes being expressed as parts of ratios.

PROJECTS

Steam Turbine ( 50 / 62 / 70 ) ('' Aeolipile '') - 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 quite some time. If he had taken a few more steps and intergrated it with his piston technology, it would have been the same as the latter day steam engines that sparked the industrial revolution, therefore possibly causing an industrial revolution almost 2000 years earlier than it happened.

automatic temple doors - controlled by the temple priest lighting an altar outside of the temple, which heated water beneath it, which then moved counterweights which would open the doors. When the fire was extinguished, the water would cool and thus return the counterweights to their original position, which closed the temple doors.

first automated, coin operated Vending Machine -- called Pneumatica -- to vend holy water for temple worshippers to cleanse their hands

Machine Gun (which fired arrows), mechanical bow (which could fire arrows with great strength), and hand-powered Catapult - these were designed but not realized because the needed materials were not yet available.

Water Organ or hydraulic organ

automated Puppet theatres using a complicated series Gears , Rods , and Rope to move small wooden figures on a "stage". Rope was wrapped around wooden rods with carefully placed pegs. As the rods rotated, the rope would unwrap accordingly, and this initiated gears and other mechanisms to move, thus putting the figures in motion. This was a primitive but effective form of Computer Programming .

omen machine - temple patrons asked a simple yes or no question, and by descretion of the priest, the answer was yes or no depending on whether the mechanical bird sitting on the top of the box would sing and twirl or not

water-powered mechanical birds - this was used in Hero's omen machine as well as entire flocks of mechanical birds. Realistic chirping sound effects also produced by a water device.

compressed-air Fountain (see Heron's Fountain )

Siphon s - this powered many of Hero's projects

machine for threading wooden Screw s

automated machine for moving full-scale theater set pieces

density of Air

Odometer

naval log, a variation of the odometer to be used at sea

Deep study (if not invention) of the Dioptra , a Surveying device similar to the Theodolite , sophisticated enough, for example, to construct a tunnel through two opposite points in a mountain.

Water vessel that remained full even after withdrawing water with a goblet

suspension of a ball above a cauldron. The suspension was due to a water filled cauldron that when lit from fire created steam which lifted the ball that was on top of a tube connected to the cauldron.

Hercules shoots arrow at hissing dragon when apple is lifted

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Hero Of Alexandria