Birthday of David Hilbert (1862)

One of the most influential mathematicians in history. Hilbert's 23 problems, presented in 1900, set the agenda for 20th-century mathematics. His formalist program aimed to place all of mathematics on a rigorous axiomatic foundation — a dream shattered by Gödel's incompleteness theorems in 1931. Hilbert's famous declaration 'We must know, we will know' became the motto of mathematical optimism. He transformed geometry, created the mathematical framework of general relativity before Einstein, and founded functional analysis.