(February 13, 1805 – May 5, 1859)
Peter Dirichlet was among the budding mathematicians Henrik Abel met during his mainland European tour. And he envied the fact that Dirichlet, whom he considered his junior in both age and ability, was already on his path to lectureship. But that was part of the advantages of living in mainland Europe (which include: more interactions, more opportunities, fluency in Latin, as well as easier access to publications). Still, his ability (though a shade beneath Abel’s) is unquestionable. He was a top genius whose ingenuity Bernhard Riemann ranked next to Gauss’. And upon Gauss’ death in 1855, he succeeded him at Goettingen. But long before all that, Georg Simon Ohm had mentored a young Peter Dirichlet: whetting his lifelong appetite for maths. He would later develop Analytical Number Theory, work astoundingly on Algebra, and expand the scope of Fourier series. A rigorous theorem prover as well as an inspiring tutor, his students included Bernhard Riemann, Richard Dedekind, Gotthold Eisenstein and Leopold Kronecker: all of whom held him in high esteem. As with other great mathematicians, he foraged into physics: where his exploits on Hydrodynamics and the Theory of Heat made headlines. He even improved upon Lagrange’s work on Conservative Systems. His brilliance was such that after his death in 1859, his brain was removed before his burial; and is preserved at the Physiology Department of the Goettingen University (just like Carl Gauss’). As memorials, the Dirichlet lunar impact crater, the Dirichlet-Jackson lunar basin, and the 11665 Dirichlet asteroid, were dedicated to him.