Mathematics
Harary's work in graph theory was diverse. Some topics of great interest to him were:
- Graph enumeration, that is, counting graphs of a specified kind. He coauthored a book on the subject (Harary and Palmer 1973). The main difficulty is that two graphs that are isomorphic should not be counted twice; thus, one has to apply Polya's theory of counting under group action. Harary was an expert in this.
- Signed graphs. Harary invented this branch of graph theory, which grew out of a problem of theoretical social psychology investigated by the psychologist Dorwin Cartwright and Harary.
- Applications of graph theory in numerous areas, especially to social science. He was co-author of John Wiley's first eBook, Graph Theory and Geography.
Among over 700 scholarly articles Harary wrote, two were co-authored with Paul Erdős, giving Harary an Erdős number of 1. He lectured extensively and kept alphabetical lists of the cities where he spoke.
Read more about this topic: Frank Harary
Famous quotes containing the word mathematics:
“Why does man freeze to death trying to reach the North Pole? Why does man drive himself to suffer the steam and heat of the Amazon? Why does he stagger his mind with the mathematics of the sky? Once the question mark has arisen in the human brain the answer must be found, if it takes a hundred years. A thousand years.”
—Walter Reisch (1903–1963)
“Mathematics alone make us feel the limits of our intelligence. For we can always suppose in the case of an experiment that it is inexplicable because we don’t happen to have all the data. In mathematics we have all the data ... and yet we don’t understand. We always come back to the contemplation of our human wretchedness. What force is in relation to our will, the impenetrable opacity of mathematics is in relation to our intelligence.”
—Simone Weil (1909–1943)