Editing Blaise Pascal (section)

==Early life and education==
[[File:Maison de Blaise Pascal (Clermont).png|thumb|left|200px|Pascal's birthplace]]

Pascal was born in [[Clermont-Ferrand]], which is in France's [[Auvergne (region)|Auvergne region]], by the [[Massif Central]]. He lost his mother, Antoinette Begon, at the age of three.{{sfn|Devlin|p=20}} His father, [[Étienne Pascal]], also an amateur mathematician, was a local judge and member of the "[[Nobles of the Robe|Noblesse de Robe]]".  Pascal had two sisters, the younger [[Jacqueline Pascal|Jacqueline]] and the elder [[Gilberte Périer|Gilberte]].

=== Move to Paris ===
In 1631, five years after the death of his wife,<ref name="MCS">{{cite web |last1=O'Connor |first1=J.J. |last2=Robertson |first2=E.F. |author-link1=John J. O'Connor (mathematician) |author-link2=Edmund F. Robertson |title=Étienne Pascal |url=http://www-history.mcs.st-andrews.ac.uk/Biographies/Pascal_Etienne.html |date=August 2006 |publisher=[[University of St Andrews|University of St. Andrews, Scotland]] |access-date=5 February 2010 |archive-date=19 April 2010 |archive-url=https://web.archive.org/web/20100419181846/http://www-history.mcs.st-andrews.ac.uk/Biographies/Pascal_Etienne.html |url-status=live }}</ref> Étienne Pascal moved with his children to Paris. The newly arrived family soon hired Louise Delfault, a maid who eventually became a key member of the family. Étienne, who never remarried, decided that he alone would educate his children.

The young Pascal showed an extraordinary intellectual ability, with an amazing aptitude for mathematics and science.<ref>{{Cite web |date=2024-04-08 |title=Blaise Pascal {{!}} Biography, Facts, & Inventions {{!}} Britannica |url=https://www.britannica.com/biography/Blaise-Pascal |access-date=2024-04-19 |website=www.britannica.com |language=en}}</ref>  Etienne had tried to keep his son from learning mathematics; but by the age of 12, Pascal had rediscovered, on his own, using charcoal on a tile floor,  [[Euclid]]’s first thirty-two geometric propositions, and was thus given a copy of Euclid's [[Euclid's Elements|''Elements'']].<ref>Cole, J. R. (1995). Pascal : the man and his two loves. United Kingdom: NYU Press. p. 40</ref>

==== ''Essay on Conics'' ====
Particularly of interest to Pascal was a work of [[Gérard Desargues|Desargues]] on [[conic section]]s. Following Desargues' thinking, the 16-year-old Pascal produced, as a means of proof, a short treatise on what was called the ''Mystic [[Hexagram]]'', ''Essai pour les coniques'' (''Essay on Conics'') and sent it — his first serious work of mathematics — to [[Marin Mersenne|Père Mersenne]] in Paris; it is known still today as [[Pascal's theorem]]. It states that if a [[hexagon]] is inscribed in a circle (or conic) then the three intersection points of opposite sides lie on a line (called the Pascal line).

Pascal's work was so precocious that [[René Descartes]] was convinced that Pascal's father had written it. When assured by Mersenne that it was, indeed, the product of the son and not the father, Descartes dismissed it with a sniff: "I do not find it strange that he has offered demonstrations about conics more appropriate than those of the ancients," adding, "but other matters related to this subject can be proposed that would scarcely occur to a 16-year-old child."<ref>''[[The Story of Civilization]]: Volume 8, "The Age of Louis XIV"'' by [[Will Durant|Will & Ariel Durant]]; chapter II, subsection 4.1 p. 56</ref>

===Leaving Paris===
In France at that time offices and positions could be—and were—bought and sold. In 1631, Étienne sold his position as second president of the ''[[Cour des Aides]]'' for 65,665 [[Livre tournois|livres]].<ref>Connor, James A., ''Pascal's wager: the man who played dice with God'' (HarperCollins, NY, 2006) {{isbn|0-06-076691-3}} p. 42</ref> The money was invested in a [[government bond]] which provided, if not a lavish, then certainly a comfortable income which allowed the Pascal family to move to, and enjoy, Paris, but in 1638 [[Cardinal Richelieu]], desperate for money to carry on the [[Thirty Years' War]], defaulted on the government's bonds. Suddenly Étienne Pascal's worth had dropped from nearly 66,000 livres to less than 7,300.{{citation needed|date=May 2023}}

Like so many others, Étienne was eventually forced to flee Paris because of his opposition to the fiscal policies of Richelieu, leaving his three children in the care of his neighbour Madame Sainctot, a great beauty with an infamous past who kept one of the most glittering and intellectual salons in all France. It was only when Jacqueline performed well in a children's play with Richelieu in attendance that Étienne was pardoned. In time, Étienne was back in good graces with the Cardinal and in 1639 had been appointed the king's commissioner of taxes in the city of [[Rouen]]—a city whose tax records, thanks to uprisings, were in utter chaos.

===Pascaline===
[[File:Pascaline-CnAM 823-1-IMG 1506-black.jpg|thumb|An early [[Pascaline]] on display at the [[Musée des Arts et Métiers]], Paris|alt=]]
In 1642, in an effort to ease his father's endless, exhausting calculations, and recalculations, of taxes owed and paid (into which work the young Pascal had been recruited), Pascal, not yet 19, constructed a mechanical calculator capable of addition and subtraction, called ''[[Pascal's calculator]]'' or the ''Pascaline''. Of the eight Pascalines known to have survived, four are held by the [[Musée des Arts et Métiers]] in Paris and one more by the [[Zwinger museum]] in [[Dresden]], Germany, exhibit two of his original mechanical calculators.<ref>A complete list of known Pascalines and also a review of contemporary replicas can be found at [http://metastudies.net/pmwiki/pmwiki.php?n=Site.SurvivingPascalines Surviving Pascalines] {{Webarchive|url=https://web.archive.org/web/20211105180308/http://metastudies.net/pmwiki/pmwiki.php?n=Site.SurvivingPascalines |date=5 November 2021 }} and [http://metastudies.net/pmwiki/pmwiki.php?n=Site.ReplicaPascalines Replica Pascalines] {{Webarchive|url=https://web.archive.org/web/20211105181911/http://metastudies.net/pmwiki/pmwiki.php?n=Site.ReplicaPascalines |date=5 November 2021 }} at http://things-that-count.net {{Webarchive|url=https://web.archive.org/web/20181215022135/http://things-that-count.net/ |date=15 December 2018 }}</ref>

Although these machines are pioneering forerunners to a further 400 years of development of mechanical methods of calculation, and in a sense to the later field of [[computer engineering]], the calculator failed to be a great commercial success. Partly because it was still quite cumbersome to use in practice, but probably primarily because it was extraordinarily expensive, the Pascaline became little more than a toy, and a [[status symbol]], for the very rich both in France and elsewhere in Europe. Pascal continued to make improvements to his design through the next decade, and he refers to some 50 machines that were built to his design.<ref>[http://fr.wikisource.org/wiki/La_Machine_d%E2%80%99arithm%C3%A9tique (fr) La Machine d'arithmétique, Blaise Pascal] {{Webarchive|url=https://web.archive.org/web/20110515015452/http://fr.wikisource.org/wiki/La_Machine_d%E2%80%99arithm%C3%A9tique |date=15 May 2011 }}, Wikisource</ref> He built 20 finished machines over the following 10 years.<ref>{{cite book|last=Mourlevat|first=Guy|title=Les machines arithmétiques de Blaise Pascal|publisher=La Française d'Edition et d'Imprimerie|year=1988|location=Clermont-Ferrand|page=12|language=fr}}</ref>