Leonhard Euler was born on April 15th, 1707 in Basel Switzerland. When he was born, the little town of Basel was a large "centre" of math in all Europe. Later in his childhood at the young age of 7, his father hired a mathematical tutor to come and help Euler. His talented tutor Bernoulli was another very well known and talented mathematician of that time. Euler was very involved with math at a young age.

Euler was starting to become more interested in math by the time he was13 years old. He started to attend college lectures at Basel University. Euler was so talented that he earned his masters degree at age 16! His talent was not recognized as much as it should have been as he was turned down for a job as a physics professor at the local University, where he was educated, Basel University. Right after he was rejected, St. Petersburg Academy invited him to work for them.

It was here that he unleashed his true talents. His work became much more popular and influential. He was well known for his theories of the production of the human voice, sound and music, mechanics of vision and his telescopic and microscopic perception work. We can attribute the telescope and microscope to his work. He left Russia because of the political termoil that surrounded him. He eventually moved back to Berlin after getting offered a job at the Berlin Academy of Sciences.

Once in Berlin, he was appointed as the head of Berlin Observatory and also tutored both of the king of Prussia's nieces. He was also involved in highly heated philosophical debates. While in Berlin, he published his ideas on the calculus of variations. He also had a lot of mathematical projects that the king of Germany had him work on. They were everyday problems involving the wellfare of the people. These included pension plans, calculations to navigate around the cities, coin circulation and systems to supply water. His philosophical views eventually became unpopular in Germany so he moved back to Russia and was observing how venus moved across the sun. He did this in spite of his already significant vision problems.

While in Russia, he went completley blind but didn't stop him from developing in the area of mathematics. He was given a head position at the academy of sciences and continued to study the movement of venus. He calculated the positioning of the moon and how that affected the moving tides on earth. He was able to calculate the orbit of Uranus. He published one of his most important pieces of all time which was on calculus applied to everyday situations.

It is argued that his most important mathematical contribution was the Konigsberg bridge problem. The town had a river and there were two islands in the center of the river. There were 7 bridges connected to the island and the sides. 3 bridges connected to both sides of the river and the other 4 bridges were connected to the first island and 3 bridges connected to both islands. Everyone in the town was curious if it was possible to cross all 7 bridges in one trip.

He came up with a formula to determine that it was impossible to cross only once in the trip. This eventually led to the graph theory which was the foundation of topography. "Euler figured that if k represented the number of bridges approaching a region, then (k+1)/2 and k/2 represented the number of times a region with an odd and even number of bridges respectfully could be crossed without violating the rules. He then figured that if the sum of these numbers was greater than the total number of bridges plus one (in this case 8, since 7+1=8), then it was impossible to cross all the bridges only once in one trip"(Stiffler,1).

One of the most intresting facts about Euler as a person is how he lost his vision. He was studying how Venus moved across the sun even though he already had significant damage to his eyesight. This damage occurred when the light diffraction experiment went wrong. He had surgery on his eye and something went wrong. Studying the patterns of venus across the sun with these problems made them worse and he eventually went completely blind.

This is the most interesting thing because half of his publications and discoveries came from after he went blind. This shows his dedication and strong will to mathematics. The king of Prussia who disfavored Euler, called him a "mathematical cyclops". While still in Russia, his main focus to his work was working with the everyday problems. He managed the direction of the underground water flow in the city. Another one of his major studies in Russia was the motion of the rigid body.

Euler was one of the most "prolific" mathematicians in all history. He was well known for his skill to explain things in to great detail. He was a generous and kind man. He loved children which explained his very sudden death. In 1783 while Euler was playing with his young grandson, he suffered from an unexpected heart attack which tool his life.