Archimedes, of Syracuse 

Biographical Information 

Occupation, Sphere of Activity 
Archimedes of Syracuse (c287212 BC) was a mathematician and inventor. His father was Pheidias, an astronomer, of which we know nothing. While he is famous now, as he was then, largely because of his inventions, it is reported that he despised invention as being less "pure" than geometry, and he never wrote about his creations. Little is known about his life, though he is described by some as having been a relative  by others as a close friend  of Hiero (or Hieron) II, King of Syracuse, who employed him as a tutor to his son. He almost certainly spent a part of his life studying in Alexandria  where he is thought to have played an important role in the development of Euclidian mathematics. It is probably here that he met Conon of Samos, who he remained in correspondence with as a personal as well as professional friend. Among the inventions he is credited with is the Screw of Archimedes, an early type of pump he is thought to have created when in Alexandria, which is still used in traditional agriculture in some areas of the world. He is also  almost certainly apocryphally  said to have installed an arrangement of mirrors on the city defences of Syracuse which set fire to attacking Roman ships. He is believed to have invented the compound pulley as a way of demonstrating the possibility of moving very large masses  he bragged that, moved to a position outside the Earth, he could move the entire planet without difficulty. More famously (though also less probably), he is said to have thought of a way of proving King Hiero II had been cheated when supplied with a new crown, by comparing the mass and volume of a block of pure gold of equal mass with the crown. By showing the crown had a larger volume than the equally massive block of gold, so the story goes, he proved that a metal with a lower density had been added to the gold. While the story is improbable, it may relate to one of his real achievements, the elucidation of Archimedes' Law, which explains the change in weight due to buoyancy experienced by objects submerged in water. He wrote a number of books, ten of which have survived largely intact. These deal mostly with geometrical problems  particularly centres of gravity of solids, studies of spheres and conical sections, spirals and other mathematical matters. Among his propositions, particularly interestingly, are an approximation of 'pi'  which he reached after circumscribing and inscribing a circle with two 96sided polygons, an explanation of the law of levers, a foundation for theoretical mechanics, a means of accurately approximating square roots of large numbers, a precursor to Newton and Leibniz's calculus and a proposed system of numbering for large figures which went high enough  8x10^16 in modern notation  to count to a higher number than the number of grains of sand that would fill the universe  or so Archimedes believed. Archimedes' work the Sandreckoner, in which he introduces his number system, is of historical interest, because it contains an early reference to Aristarchus' heliocentric system and uses results of Phidias (his father) and Eudoxus to determine the size of the universe. It is dedicated to Gelo (Gelon), King Hiero's son. In his book, the Method, Archimedes explains his scientific methods to the reader, and is a unique document, detailing how one of the greatest minds of the classical world worked. In On the Sphere and the Cylinder, which he considered to be his most important work, Archimedes proves that a sphere's surface area is two thirds that of the circumscribing cylinder (including bases) and a sphere's volume is two thirds that of a circumscribing cylinder. 
Relationships 
Archimedes was the son of astronomer Pheidias. He had a close relationship with astronomer and mathematician Conon of Samos. 
Other Significant Information 
Notable publications: On Plane Equilibria or Centres of Gravity of Planes On the Sphere and the Cylinder On Spirals On Floating Bodies The Sandreckoner Method On Conoids and Spheroids A Collection of Lemmas The Quadrature of Parabola The Measurement of the Circle 
Honours, Qualifications and Appointments 
None known 
Notes 
List of sources for the biographical information: Encyclopaedia Britannica vol II, (
