March 15, 2023
Instead of six degrees of Kevin Bacon, think Paul Erdős.
One of the 20th century’s most influential minds, the Hungarian mathematician earned his stripes by posing and solving complex problems in number theory and founding the field of discrete mathematics, widely acknowledged as fundamental to the development of computer science and artificial intelligence.
Erdős’ prolific career took him around the world as he collaborated with more than 500 mathematicians, paving the way for the computing revolution and modern search engines. His collaborations were so far-reaching that they gave rise to another phenomenon: the “Erdős number” is the number of steps needed to connect a research paper’s author to Paul Erdős.
An author's Erdős number is 1 if they have co-authored a paper with Erdős, 2 if they have co-authored a paper with someone who has co-authored a paper with Erdős, and so on. Erdős, himself, has an Erdős number of 0.
Jerrold Grossman, OU professor emeritus of mathematics, created the Erdős Number Project as a source of information for research mathematicians and others interested in the phenomenon of collaboration in mathematics research. He maintains the project’s website, noting that Erdős numbers have been a part of the folklore of mathematicians around the world for many years.
Using data from the American Mathematical Society, Dr. Grossman found that approximately 80 percent of mathematicians have an Erdős number, ranging from 1 to 13, with the average being about 5. Currently, the website lists 11,514 people with an Erdős number less than or equal to 2, including Fields Medalists and Nobel Prize winners.