Aristoteles

Aristotle was born in Stagira, on the peninsula of Chalcidice in Macedon, N Greece (hence his nickname "the Stagirite"). His father was Nichomachus, court physician to Amyntas III of Macedonia (the father of Philip II of Macedon and grandfather of Alexander the Great), and he was no doubt introduced to Greek medicine and biology at an early age. In 367 B.C., after his father's death he was sent to Athens, and became first a pupil then a teacher at Plato's Academy. He remained there for 20 years, until Plato's death in 347 B.C., and gained a particular reputatoin in rhetoric. Plato was succeeded as head of the Academy by his nephew Speusippus. Perhaps in pique, but more probably because of the rise of anti-Macedonian feeling in Athens, Aristotle left the city to travel for some 12 years with other colleagues and friends from the Academy, notably Theophrastus (his own pupil and eventual successor at the Lyceum). He went first to the new town of Assus in Asia Minor, where Hermeias of Atarneus had invited him to help set up a new school, and where he worked particularly on political theory. He there married Hermeias' niece, Pythias, and after her early death either married Herpyllis or took her as his mistress. In addition to Pythias' daughter (also called Pythias), he and Herpyllis had a son, Nicomachus (named after his father). He was an affectionate and faithful husband, and a caring parent. After three years at the Assus Academy, Aristotle then moved to join a new philosophical circle at Mytilene on Lesbos, where he developed his interest in and study of biology. In c.343 B.C. he was invited by Philip II of Macedon to educate his son, the future Alexander the Great. he was tutor to Alexander for three years, but his influence seems to have been negligible. After a brief spell on his father's property at Stagira, Aristotle returned to Athens in 335 B.C. to found his own school, the Lyceum (near the temple of Apollo Lyceius), where he taught for the next 12 years. His followers became known as peripatetics, supposedly from his practice of walking up and down the peripatos (covered walkway) of the gymnasium during his lectures. He made the Lyceum into a major research center, specializing in history, biology, and zoology, thus complementing the mathematical emphasis of the Platonists at the Academy. Alexander the Great died in 323 B.C., and there was a strong anti-Macedonian reaction in Athens. Aristotle, of course, had long-standing Macedonian connections, and took refuge in Chalcis in Euboea, reportedly saying that he was saving the Athenians from sinning twice against philosophy (Socrates being their first victim). He died the following year. Aristotle's work represents an enormous encyclopedic output over virtually every field of knowledge: logic, metaphysics, ethics, politics, rhetoric, poetry, biology, zoology, physics, and psychology. Indeed, he established many of the areas of enquiry which are today recognizable as separate subjects; and in several cases gave them their names and special terminology. Particular themes which run through his work are the emphasis on teleological explanations, and his analyses of such fundamental dichotomies as matter and form, potentiality and actuality, substance and accident, and particulars and universals. His popular published writings are all lost, and the bulk of the work that survives consists of unpublished material in the form of lecture notes or students' textbooks which were edited and published by Andronicus of Rhodes in the middle of the 1st-C B.C. But even this incomplete corpus is extraordinary for its range, originality, systematization, and sophistication. It exerted an enormous influence on mediaeval philosophy (especially through Aquinas), on Islamic philosophy (especially through Averroes), and indeed on the whole Wetern intellectual and scientific tradition. During the Renaissance he was dubbed "the Master of those that know", or simply "the Philosopher". Aristotle's most widely read books today include the Organon (treatises on logic), Metaphysics (the book written after Physics), Nicomachean Ethics, Politics, Poetics, and De Anima.

James Watt

ames Watt was a genius of many talents who was at the heart of the technological and economic changes in 18th century Britain that have been described as the Industrial Revolution. He was born in Greenock, the son of James Watt (1698-1782), a prosperous merchant and prominent citizen of the Scottish port. He had a talent for mathematics, and trained as a maker of mathematical instruments in Glasgow, making a visit to London to gain professional experience in 1755-6. He gained the acquaintance of the celebrated Dr Joseph Black (1728-99) of Glasgow University who described him as ‘a young man possessing most uncommon talents for mechanical knowledge and practice’. He learned German and Italian, took an interest in several new technologies, including the manufacture of porcelain, and carried out surveys of several Scottish waterways, including the Caledonian Canal, that were subsequently praised by Thomas Telford. His main interest was in the improvement of the steam engine, and after erecting several Newcomen engines in Scotland in 1765-6, he took out his first patent, for the separate condenser, in 1769. He moved to Birmingham in 1774 where, he worked in partnership with Matthew Boulton (1728-1809), to develop the steam engine. The first engines to incorporate his improvements were erected in 1776. Initially the Boulton and Watt partnership supplied only drawings, some key components such as valves, and the services of erectors. Watt was only one of many engineers developing steam power in the late 18th century, and his application of sun-and-planet gearing to achieve rotative motion, patented in 1782, was dictated by the granting of a patent to James Pickard for the use of the crank for this purpose. Watt was concerned to ensure that high standards were achieved in his engines, and would use only Swedish iron purchased from merchants in Birmingham for some engine parts. He supplied his first overseas order in 1778, and by 1800, when his patents expired, Boulton & Watt had despatched 24 engines to customers in France, Germany, Italy, Spain, Netherlands, Austria, Sweden and Russia.

In the 1790s it became evident that other engine builders, notably the ironmaster John Wilkinson, had infringed the Watt patents by building ‘pirate’ engines. Watt developed elements of paranoia over such infringements, but after the partners established their own engine-building facilities, by opening the Soho Foundry in 1796, he gradually retired from the business. In the interval of peace that followed the treaty of Amiens in 1802 he visited Frankfurt, Strasburg and Paris. Watt also developed a copying process in 1781. Copies were kept of engine drawings and of the outgoing letters of the partnership, while incoming letters were also preserved, making the Boulton & Watt Collection in Birmingham one of the most important archives of the Industrial Revolution.

Watt retained throughout his life interests in geology, mineralogy and chemistry, and was honoured for his scientific achievements in Russia, the Netherlands and France, but never regarded his own achievements as in any way heroic.

Archimedes

Archimedes of Syracuse (c. 287 BC – c. 212 BC) was a Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and the explanation of the principle of the lever. He is credited with designing innovative machines, including siege engines and the screw pump that bears his name. Modern experiments have tested claims that Archimedes designed machines capable of lifting attacking ships out of the water and setting ships on fire using an array of mirrors.

Archimedes is generally considered to be the greatest mathematician of antiquity and one of the greatest of all time. He used the method of exhaustion to calculate the area under the arc of a parabola with the summation of an infinite series, and gave a remarkably accurate approximation of Pi.He also defined the spiral bearing his name, formulas for the volumes of surfaces of revolution and an ingenious system for expressing very large numbers.

Archimedes died during the Siege of Syracuse when he was killed by a Roman soldier despite orders that he should not be harmed. Cicero describes visiting the tomb of Archimedes, which was surmounted by a sphere inscribed within a cylinder. Archimedes had proved that the sphere has two thirds of the volume and surface area of the cylinder (including the bases of the latter), and regarded this as the greatest of his mathematical achievements.

Unlike his inventions, the mathematical writings of Archimedes were little known in antiquity. Mathematicians from Alexandria read and quoted him, but the first comprehensive compilation was made only by Isidore of Miletus (c. 530 AD), while commentaries on the works of Archimedes written by Eutocius in the sixth century AD opened them to wider readership for the first time. The relatively few copies of Archimedes' written work that survived through the Middle Ages were an influential source of ideas for scientists during the Renaissance, while the discovery in 1906 of previously unknown works by Archimedes in the Archimedes Palimpsest has provided new insights into how he obtained mathematical results