Erdös numbers have been a part of the myth of mathematicians for many years. Due to the very high frequency of interdisciplinary collaboration in science today and due to the fact that mathematics is basic to science disciplines, very large numbers of non-mathematicians also have finite Erdös numbers. Not only that; many linguists, political scientists, and Nobel laureates have finite (less than 8) Erdös numbers.

 

The Erdös number is the "collaborative distance" 0, or 1, or 2, or 3, or 4, or … between a person and mathematician Paul Erdös, as measured by authorship of mathematical papers. It was created by friends as a comical accolade to the massive contribution of Erdös to mathematics. Erdös is considered as was one of the terrific modern writers of mathematical papers, and has become well-known in scientific circles as a tongue-in-cheek measurement of mathematical celebrity. Paul Erdös is the one person having an Erdös number of zero. For any authors other than Erdös, if the author has coauthored with Erdös or an author of Erdös number n a number, then that author's Erdös number is one more than n. Lower the value of n, the author is more closure to Paul Erdös’s mathematical ability.

 

Paul Erdös was a dominant and nomadic Hungarian mathematician. He spent a portion of his life living out of a suitcase and writing papers with those scholars willing to give him room and board. He published more papers during his life (at least 1,400) than any other mathematicians in history including the Swiss mathematician and physicist Leonhard Euler who is considered the father of Calculus. Paul Erdös was born in Budapest, Hungary on March 26, 1913. In 1934, at the age of 21, he was awarded a doctorate in mathematics. In 1938, he accepted a position at Princeton University, NJ, USA. At this time, he began to develop the habit of traveling from institute to institute from country to country. He would not stay long in one place and traveled back and forth among mathematical institutions. Erdös visited the Indian Statistical Institute (ISI) Calcutta and School of Mathematics, Tata Institute of Fundamental Research (TIFR), Mumbai. During the last decades of his life, Erdös received at least fifteen honorary doctorates. He became a member of the scientific academies of eight countries, including the U.S. National Academy of Sciences and the UK Royal Society. Erdös never married and had no children. At Alfred Nobel’s fault, Erdos did not get his Nobel Prize; Alfred did not list mathematics as one of the disciplines. Erdös’s life was documented in the film “N Is a Number: A Portrait of Paul Erdös”, made while he was still alive.

 

In 2004, Bill Tozier, a researcher with an Erdös number of 4, offered the chance for collaboration to attain an Erdös number of 5 in an auction on eBay. The final bid was $1,031, though apparently the winning bidder had no intention to pay. The winner who already had an Erdös number of 3 considered it a "mockery", and said "papers have to be worked and earned, not sold, auctioned or bought". It is teasingly said that American baseball player Hank Aaron has an Erdös number of 1 because he autographed a baseball with Erdös when Emory University awarded them both honorary degrees on the same day.

 

Krishnaswami Alladi, Sarvadaman Chowla, Hansraj Gupta, Renu Laskar, M. Ram Murty, V Kumar Murty, SB Rao, Navin Singhi and Mathukumalli V Subbarao earned Erdös number 1. There are many (25 to 50) mathematicians of Indian origin who have Erdös number 2. There will be no more mathematicians with Erdös number 1 while Professor Paul Erdös died "in action" of a heart attack on 20 September 1996, at the age of 83, while attending a conference in Warsaw, Poland.

 

There are other funny numbers similar to Erdös number. The “Bacon number” is an application of the same idea to the movie industry, connecting actors that appeared in a film together to the actor Kevin Bacon. Although this is the most well-known "number", it was conceived of in 1994, 25 years after the Erdös number spin off. The lowest known Erdös-Bacon is 3 for Daniel Kleitman a mathematics professor at Massachusetts Institute of Technology (MIT) who acted in 1997 Oscar awarded movie “Good will Hunting”; Kleitman’s Erdös number is 1 and his Bacon number is 2.

 

Reference may also be made to: http://www.oakland.edu/enp/


From the Internet

http://en.wikipedia.org/wiki/Erd%C5%91s_number


If Alice collaborates with Paul Erdös on one paper, and with Bob on another, but Bob never collaborates with Erdös himself, then Bob is given an Erdös number of 2, as he is two steps from Erdös.



Erdös wrote around 1,400 mathematical articles in his lifetime, mostly co-written. He had 511 direct collaborators; these are the people with Erdös number 1. The people who have collaborated with them (but not with Erdös himself) have an Erdös number of 2 (8,162 people as of 2007), those who have collaborated with people who have an Erdös number of 2 (but not with Erdös or anyone with an Erdös number of 1) have an Erdös number of 3, and so forth. A person with no such coauthorship chain connecting to Erdös has an Erdös number of infinity (or an undefined one).


Erdös's vocabulary include:

·         Children were referred to as "epsilons" (in mathematics, particularly calculus, an arbitrarily small positive quantity is commonly denoted by that Greek letter (ε));

·         Women were "bosses";

·         Men were "slaves";

·         People who stopped doing math had "died";

·         People who physically died had "left";

·         Alcoholic drinks were "poison";

·         Music was "noise";

·         People who had married were "captured";

·         People who had divorced were "liberated";

·         To give a mathematical lecture was "to preach" and

·         To give an oral exam to a student was "to torture" him/her.


Erdös problems

Throughout his career, Erdös would offer prizes for solutions to unresolved problems. These ranged from $25 for problems that he felt were just out of the reach of current mathematical thinking, to several thousand dollars for problems that were both difficult to attack and mathematically significant. There are thought to be at least a thousand such outstanding prizes, though there is no official or comprehensive list. The prizes remain active despite Erdös's death; Ronald Graham is the (informal) administrator of solutions. Winners can get either a check signed by Erdös (for framing only) or a cashable check from Graham.

 

Perhaps the most notable of these problems is the Erdös conjecture on arithmetic progressions:

 

If the sum of the reciprocals of a sequence of integers diverges, then the sequence contains arithmetic progressions of arbitrary length.

 

If true, it would solve several other open problems in number theory (although one main implication of the conjecture, that the prime numbers contain arbitrarily long arithmetic progressions, has since been proved independently as the Green-Tao theorem.) The problem is currently worth US$5000.