# Danilo Blanusa

**Danilo Blanuša**(December 7 1903 - August 8 1987) was a Croatian mathematician, physicist, engineer and a professor at the University of Zagreb.

Blanuša was born in Osijek and attended elementary school in Vienna and Steyer in Austria and gymnasium in Osijek and Zagreb. He studied engineering in both Zagreb and Vienna and also mathematics and physics. His career started in Zagreb where he started to work and lecture. Blanuša received the Ruđer Bošković prize in 1960.

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2 Physics 3 External links |

## Mathematics

In mathematics, BlanuÚa became famous for discovering the second and third known snarks in 1946 (the Petersen graph was the first), triggering a new area of graph theory. Snarks are bridgeless cubic graphss with edge chromatic number of at least four. In other words, they are graphs in which every node has three branches, and the nodes cannot be coloured in fewer than four colours without two nodes of the same colour meeting at a point. These graphs are part of the solution of the 'four color problem', i.e. the proof of the four color theorem. (Snarks were so named by the American mathematician Martin Gardner in 1976, after the mysterious and elusive object of the poem *The Hunting of the Snark* by Lewis Carroll.)

BlanuÚa's most important works were related to isometric immersions of two-dimensional Lobachevsky plane into six-dimensional Euclid ean space and generalizations, in the theory of the special functions (Bessel functions), in differential geometry, and in graph theory. His result are included in the Japanese mathematical encyclopedia *Sugaku jiten* in Tokyo, (1962) published by *Iwanami shoten*.

## Physics

His works were mostly related to the theory of relativity. He discovered a mistake in relations for absolute heat Q and temperature T in relativistic phenomenological thermodynamics, published by Max Planck in *Annalen der Physik* in 1908.

- Q0 and T0 are the corresponding classical values, and a=(1-v2/c2)1/2

in the relation ---> Q=Q0a, T=T0a

really should be ---> Q=Q0/a, T=T0/aThis correction was published in

*Glasnik*, the journal relating to mathematics, physics and astronomy in 1947 in article "Sur les paradoxes de la notion d'énergie". It was rediscovered in 1960 and the correction is still wrongly attributed to H. Ott in the mainstream scientific literature.