Eureka is an interjection used to celebrate a discovery or invention. It is a transliteration of an exclamation attributed to Ancient Greek mathematician and inventor Archimedes.
Archimedes exclaiming Eureka. In his excitement, he forgets to dress and runs nude in the streets straight out of his bath (drawing by Pietro Scalvini, engraving by Carlo Orsolini, 1737)
16th-century illustration of Archimedes in the bath, with Hiero's crown at bottom right
The Seal of California, featuring the word "EUREKA" above the spear of the goddess Minerva, from 1870
Archimedes of Syracuse was an Ancient Greek mathematician, physicist, engineer, astronomer, and inventor from the ancient city of Syracuse in Sicily. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Considered the greatest mathematician of ancient history, and one of the greatest of all time, Archimedes anticipated modern calculus and analysis by applying the concept of the infinitely small and the method of exhaustion to derive and rigorously prove a range of geometrical theorems. These include the area of a circle, the surface area and volume of a sphere, the area of an ellipse, the area under a parabola, the volume of a segment of a paraboloid of revolution, the volume of a segment of a hyperboloid of revolution, and the area of a spiral.
Archimedes Thoughtful by Domenico Fetti (1620)
Cicero Discovering the Tomb of Archimedes (1805) by Benjamin West
Front page of Archimedes' Opera, in Greek and Latin, edited by David Rivault (1615)
Ostomachion is a dissection puzzle found in the Archimedes Palimpsest.