Pascal5 (24K)
Descartes1 (5K)
HUygens (10K)
pascalineB (8K)
livrax (20K)

Blaise Pascal

19. júna 1623 Clermont - 19. augusta 1662 Paríž
PascalC (8K)
Paexp2 (7K)

Blaise Pascal was the third of Étienne Pascal's children and his only son. Blaise's mother died when he was only three years old. In 1632 the Pascal family, Étienne and his four children, left Clermont and settled in Paris. Blaise Pascal's father had unorthodox educational views and decided to teach his son himself. Étienne Pascal decided that Blaise was not to study mathematics before the age of 15 and all mathematics texts were removed from their house.

Blaise however, his curiosity raised by this, started to work on geometry himself at the age of 12. He discovered that the sum of the angles of a triangle are two right angles and, when his father found out, he relented and allowed Blaise a copy of Euclid. In December 1639 the Pascal family left Paris to live in Rouen where Étienne had been appointed as a tax collector for Upper Normandy. Shortly after settling in Rouen, Blaise had his first work, Essay on Conic Sections published in February 1640.

Pascal invented the first digital calculator to help his father with his work collecting taxes. He worked on it for three years between 1642 and 1645. The device, called the Pascaline, resembled a mechanical calculator of the 1940s. This, almost certainly, makes Pascal the second person to invent a mechanical calculator for Schickard had manufactured one in 1624. There were problems faced by Pascal in the design of the calculator which were due to the design of the French currency at that time. There were 20 sols in a livre and 12 deniers in a sol.

The system remained in France until 1799 but in Britain a system with similar multiples lasted until 1971. Pascal had to solve much harder technical problems to work with this division of the livre into 240 than he would have had if the division had been 100.

However production of the machines started in 1642. By 1652 fifty prototypes had been produced, but few machines were sold, and manufacture ceased in that year. Events of 1646 were very significant for the young Pascal. In that year his father injured his leg and had to recuperate in his house. He was looked after by two young brothers from a religious movement just outside Rouen. They had a profound effect on the young Pascal and he became deeply religious.

From about this time Pascal began a series of experiments on atmospheric pressure. By 1647 he had proved that a vacuum existed. Descartes visited Pascal on 23 September. His visit only lasted two days and the two argued about the vacuum which Descartes did not believe in. Descartes wrote, rather cruelly, in a letter to Huygens after this visit that Pascal ".has too much vacuum in his head".

In August of 1648 Pascal observed that the pressure of the atmosphere decreases with height and deduced that a vacuum existed above the atmosphere.

From May 1653 Pascal worked on writing Treatise on the Equilibrium of Liquids. Perhaps as a mathematician Pascal is best known in connection with his correspondence with Fermat in 1654 in which he laid down the principles of the theory of probabilities

The last mathematical work of Pascal was that on the cycloid in 1658. Following a mystical experience in late 1654, devoted himself to philosophy and theology. His two most famous works date from this period: the Lettres provinciales and the Pensées.

Pascal had poor health especially after his eighteenth year and his death came just two months after his 39th birthday.

Zdroje
  1. Blaise Pascal
  2. Short history of Mathematics'
  3. Pascal (česky)
Kontakty

Stránka je v súlade s aktuálnymi normami.

Valid HTML 4.01 Transitional



Domov

©  Klára Mrázová

Blaise Pascal

Preložila Klára Mrázová

Blaise Pascal bol tretím dieťaťom Étienna Pascala, bol jediným synom, mal ešte dve sestry. Jeho matka zomrela keď mal Blaise len tri roky. V roku 1632 Pascal s celou rodinou opustil Clermont a usadili sa v Paríži. Pascalov otec mal zvláštne názory na výchovu a rozhodol sa, že bude učiť svojho syna sám. Étienne Pascal rozhodol, že Blaise sa začne učiť geometriu až po dovŕčení 15 - tich rokov a preto boli všetky matematické texty uzamknuté.

Tým sa však u Pascala vzbudila zvedavosť a začal sa geometriou zaoberať sám. Už v 12 rokoch zistil, že súčet uhlov v trojuholníku sa rovná súčtu dvoch pravých uhlov. Keď to jeho otec zistil, vzdal sa svojich názorov a dovoli synovi študovať Euklida. V r. 1639 Pascalov otec bol menovaný výbercom daní pre Hornú Normandiu a preto sa rodina Pascala presťahovala do Rouenu. Čoskoro na to vo februári 1642 Blaise publikoval svoju prvú prácu Pojednanie o kuželosečkách.

Pascal zostrojil číselnú kalkulačku, ktorá mala pomáhať jeho otcovi v jeho práci vyberača daní. Pracoval na nej štyri roky v rokoch 1642-1645. Prístroj, nazvaný Pascaline sa podobal na mechanický kalkulátor z rokov styridsiatich 20. storočia. Pascalova kalkulačka bola pravdepodobne druhá po mechanickej kalkulačke Shickardovej (1624). Pascal však musel čeliť pri konštrukcii kalkulátora problémom s francúzkou menou tej doby. 1 livra mala 20 sol a sol sa delil na 12 denierov.


Tento system sa zmenil vo Francúzsku v roku 1799, kým v Anglicku trval až do r. 1971. Pascal musel riešiť oveľa väčšie technické problémy s delením livry na 240 dielov, ako by mal pri delení na 100 dielov.


Výroba kalkulačiek začala v r. 1642, bolo vyrobených 50 prototypov. Málo bolo predaných a výroba skončila v tom istom roku. Rok 1646 bol významný pre mladého Pascala. V tom roku si jeho otec zranil nohu a zotavoval sa vo svojom dome. Opatrovali ho dvaja mladí bratia z náboženskej pospolitosti z okolia Rouenu. Tito bratia mali veľmi silný vplyv na mladého Pascala, ktorý sa stal veľmi zbožným.


V tej dobe začal Pascal sériu svojich pokusov s meraním atmosferického tlaku. V roku 1647 dokázal existenciu vákua. Descartes navštívil Pascala 23. septembra roku 1647. Jeho návšteva trvala len dva dni, počas ktorých debatovali o vákuu, v existeciu ktorého Descartes neveril. Descartes napísal, veľmi kruto v liste Huygensovi, že "Pascal má príliš veľa vákua vo svojej hlave".

V auguste r. 1648 Pascal pozoroval, že atmosferický tlak klesá s výškou a z toho vyvodil, že vákuum existuje za hranicami atmosféry.

V roku 1653 Pascal publikoval zákon hydromechaniky "Pojednanie o rovnováhe v kvapalinách" . V oblasti matematiky pravdepodobne je známy najmä z korešpondencie s Fermatom, v ktorej roku 1654 položil základy teórie pravdepodobnosti

Posledná práca Pascala z oblasti matematiky bola o cykloidách v r. 1658. Po mystickom zážitku v roku 1654, zasvätil svoj život filozófii a teológii. Jeho dve najslávnejšie práce sú z tohto obdobia: Listy vidiečanovi a Myšlienky.

Pascal bol najmä od svojich 18 rokov chatrného zdravia. Zomrel po svojich 39 narodeninách.