# Paul Erdös

Paul Erdös was born on March 26, 1913, in Budapest, Hungary into a Jewish family and died on September 20, 1996, in Warsaw, Poland. A few days after being born, his two sisters who were three and five died of Scarlet Fever. Some reports say that they died on the day he was born but this has been disputed by other people.In any case the death of his sisters caused his parents to be very protective of Paul.He was homeschooled and not allowed to leave the house until he was ten to protect him from getting sick.

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His parents, Anna and Lajos were both mathematics teachers which probably caused his obsession with math.To keep himself entertained when he was home Paul would do math problems.He said “I fell in love with numbers at a young age, they were my friends”.By the time he was three years old he was able to multiply three digit numbers in his head. World War I started right after Paul was born and his father joined the Austro-Hungarian army.When Paul was one year old his father was captured by the Russian Army and spent six years in Siberia.Lajos had learned English when he was in captivity and when he returned home in 1920 he taught English to Paul, this caused him to have a unique English accent for the rest of his life.
In 1930, at the age of 17, Paul Erdös entered the University in Budapest even though there were restrictions on Jews entering the universities in Hungary.He was allowed to enter the system because he had won a national examination.In four years he completed his undergraduate work and also received his Ph.D. in mathematics. During his time at the university he, along with some other students developed the Ramsey theory.He came up with the Ramsey theory because he felt that complete disorder is impossible.No matter how scattered something appears there are certain patterns and points within.
Erdös, in 1934 accepted a four year postdoctoral fellowship at the University of Manchester in England.At this time anti-Semitism was starting to spread in Hungary which was the main reason Erdös left for England, leaving his native Hungary.At the end of the fellowship in 1938 he migrated to the United States to accept a one year appointment at the Institute for Advanced Study in Princeton, New Jersey.It was there that he developed the field of probabilistic number theory along with another mathematician.After this he went from different universities, including Notre Dame, Stanford and John Hopkins to name a few.Paul Erdös went to these different places to work on a variety of math problems.He felt that accepting a full time position would restrict him from working on problems that interested him.This was the beginning of him going all over the world solving math problems and never holding a permanent job.
In the summer of 1941 Paul Erdös and two other mathematicians were stopped by police near a radio transmitter on Long Island.After questioning they were released because it was determined that no harm was intended.This incident caused Erdös to have an FBI record.This would come back to cause problems for him in the 1950’s when the Joe McCarthy hearings were taking place.In 1954 he was not allowed to come back to the United States from a conference in Amsterdam and the FBI record was one of the reasons they gave along with that he had corresponded with a Chinese mathematician.For the next ten years of his life he spent much of his time in Israel.Finally in 1963 after several requests over the years he was granted a visa to return to the United States.
He never married, owned a home or had a job as he felt these things would prevent him doing what he loved to do and that was solving mathematical problems.One of his sayings was “the purpose of life is to prove and to conjecture”.He also said “If you have something beautiful, you have to look out for it, so I would rather give it away”.That is why when he would earn money he would set up scholarships or set up rewards for students if they could find solutions to problems he came up with.The more difficult the problem the higher the reward he would offer.
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Paul Erdös traveled to over twenty different countries working with other mathematicians on different theories and problems. He concentrated on math his entire life and never bothered to learn the most basic things in life.He admitted that he was twenty-one before he even buttered his first piece of bread as his mother or governess had always taken care of him.Even later in life he never learned to drive a car or cook, he could not even boil water.He depended on his friends, which he had many mathematician friends all over the world, to take care of his needs.He would show up at their door and when they answered he would say “My brain is open”, which meant he was ready to do math with them.After a few days when they ran out of problems for him to solve he would leave to go to another friend’s place.Meanwhile when he was there they would feed him and make sure his clothes were clean as he only had one or two suitcases that had all of his belongings inside.

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In his lifetime he produced over 1500 papers and collaborated with more than 250 different co-authors by working nineteen to twenty hours a day with the help of coffee and amphetamines.Unlike some mathematicians he loved to work on problems with people of all ages and abilities.This encouraged his colleagues to also work together.In 1949 he and Atle Selberg found the proof of the prime number theorem, this is the frequency of primes at larger and larger numbers.This work earned him the Cole Prize in 1951.Erdös went to the first Conference on Graph Theory in 1959, a theory he helped found.The diversity of the different fields he worked in was unusual.For the final thirty years of his life he worked in the fields of geometry, set theory, partition theory, number theory and combinatorics.When he came up with a proof, he felt the need to show why the result was not just show a complicated sequence of steps.
For Paul Erdös if he told someone “That’s one for the Book”, that was the highest praise he could give somebody. To him the Book contained all the best observations and brilliant ideas in the area of math.He was so obsessed with math that if he said someone had died he meant that they had quite doing math.“To leave” is what he would say if someone were to really die.He said that “mathematics is eternal because it has an infinity of problems”.
He did not like to have people touch him and he would not shake hands with anyone.Even though he did not like any physical intimacy he was known as a friendly and compassionate person.Probably his closest friend was Ronald Graham who oversaw the mathematicians, statisticians and computer scientists at AT&T Bell Labs.Erdös depended on Graham to keep all of his papers as Erdös had no home to keep them.Erdös liked visiting with Graham and his wife Fan Chung who was also a strong mathematician.
To show what type of person Paul Erdös was, in 1984 he won the Wolf Prize worth $50,000, he only kept $720 and used the rest to start a scholarship in Israel in his parents’ memory.The U.S. National Academy of Sciences, the Hungarian Academy of Science and the British Royal Society were some of the many prestigious scientific societies that he belonged to.At the age of 83 he had a heart attack and died shortly after solving a problem in geometry at a conference in Warsaw, Poland.
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