Editing Leonhard Euler (section)

==Early life==
Leonhard Euler was born in [[Basel]] on 15 April 1707 to Paul III Euler, a pastor of the [[Reformed Church]], and Marguerite (née Brucker), whose ancestors include a number of well-known scholars in the classics.{{sfn|Gautschi|2008|p=4}} He was the oldest of four children, with two younger sisters, Anna Maria and Maria Magdalena, and a younger brother, Johann Heinrich.{{sfn|Calinger|2016|p=11}}{{sfn|Gautschi|2008|p=4}} Soon after Leonhard's birth, the Eulers moved from Basel to [[Riehen]], Switzerland, where his father became pastor in the local church and Leonhard spent most of his childhood.{{sfn|Gautschi|2008|p=4}}

From a young age, Euler received schooling in mathematics from his father, who had taken courses from [[Jacob Bernoulli]] some years earlier at the [[University of Basel]]. Around the age of eight, Euler was sent to live at his maternal grandmother's house and enrolled in the Latin school in Basel. In addition, he received private tutoring from Johannes Burckhardt, a young theologian with a keen interest in mathematics.{{sfn|Gautschi|2008|p=4}}

In 1720, at age 13, Euler enrolled at the [[University of Basel]].<ref name=":0">{{Cite book |last=Debnath |first=Lokenath |title=The Legacy of Leonhard Euler : A Tricentennial Tribute |publisher=Imperial College Press |year=2010 |isbn=978-1-84816-525-0 |location=London |pages=vii |language=en |author-link=Lokenath Debnath |url=https://archive.org/details/legacyofleonhard0000debn}}</ref> Attending university at such a young age was not unusual at the time.{{sfn|Gautschi|2008|p=4}} The course on elementary mathematics was given by [[Johann Bernoulli]], the younger brother of the deceased Jacob Bernoulli, who had taught Euler's father. Johann Bernoulli and Euler soon got to know each other better. Euler described Bernoulli in his autobiography:{{sfn|Gautschi|2008|p=5}}

<blockquote>the famous professor Johann Bernoulli [...] made it a special pleasure for himself to help me along in the mathematical sciences. Private lessons, however, he refused because of his busy schedule. However, he gave me a far more salutary advice, which consisted in myself getting a hold of some of the more difficult mathematical books and working through them with great diligence, and should I encounter some objections or difficulties, he offered me free access to him every Saturday afternoon, and he was gracious enough to comment on the collected difficulties, which was done with such a desired advantage that, when he resolved one of my objections, ten others at once disappeared, which certainly is the best method of making happy progress in the mathematical sciences.</blockquote>

During this time, Euler, backed by Bernoulli, obtained his father's consent to become a mathematician instead of a pastor.{{sfn|Calinger|1996|p=124}}<ref name="zum werk leonhard" />

In 1723, Euler received a [[Master of Philosophy]] with a dissertation that compared the philosophies of [[René Descartes]] and [[Isaac Newton]].{{sfn|Gautschi|2008|p=4}} Afterwards, he enrolled in the theological faculty of the University of Basel.<ref name="zum werk leonhard"/>

In 1726, Euler completed a dissertation on the [[Speed of sound|propagation of sound]] titled ''De Sono'',{{sfn|Calinger|2016|p=32}}<ref name="17cent"/> with which he unsuccessfully attempted to obtain a position at the University of Basel.{{sfn|Calinger|1996|p=125}} In 1727, he entered the [[French Academy of Sciences|Paris Academy]] prize competition (offered annually and later biennially by the academy beginning in 1720)<ref name=paris-acad/> for the first time. The problem posed that year was to find the best way to place the [[mast (sailing)|masts]] on a ship. [[Pierre Bouguer]], who became known as "the father of naval architecture", won and Euler took second place.{{sfn|Calinger|1996|p=156}} Over the years, Euler entered this competition 15 times,<ref name=paris-acad/> winning 12 of them.{{sfn|Calinger|1996|p=156}}