The most difficult history of Science riddles

Gaspard Monge was a French mathematician, the inventor of descriptive geometry, and the father of differential geometry. During the French Revolution he served as the Minister of the Marine, and was involved in the reform of the French educational system, helping to found the École Polytechnique.

Andreas Vesalius was a Belgian born anatomist and physician, born in 1514 into a family of physicians. He is considered the father of modern anatomy and his work the beginning of modern medicine. In 1543, at the young age of 29, Vesalius published his most important work, De Humani Corporis Fabrica Libri Septem (Seven Books on the Fabric of the Human Body), generally known as the Fabrica. The Fabrica is the most famous anatomy book ever written and also the first book on human anatomy to be reasonably accurate.

Theophrastus is often considered the father of botany for his works on plants. The two of his most important books, Enquiry into Plants and On the Causes of Plants, constitute the most important contribution to botanical science during antiquity and the Middle Ages as well as the first systemization of the botanical world.

German mathematician David Hilbert presented ten of the problems at the Paris conference of the International Congress of Mathematicians. The complete list was published later. They were all unsolved at the time, and several of them were very influential for 20th-century mathematics. Now most of them have solutions, leaving 3 unsolved and 2 more categorized as too vague to ever be described as solved.

The Galilean moons are the four largest moons of Jupiter—Io, Europa, Ganymede, and Callisto. They were first seen by Galileo Galilei in December 1609 or January 1610, and recognized by him as satellites of Jupiter in March 1610.

Eratosthenes of Cyrene was the chief librarian at the Library of Alexandria. He is best known for being the first person to calculate the circumference of the Earth. He did it by measuring Sun's angle of elevation at noon on the solstice in Alexandria, knowing, that at the same time the Sun is at Zenith in the Ancient Egyptian city of Swenet, 5000 stades from Alexandria. Seventeen hundred years after Christopher Columbus studied Eratosthenes writings and decided that the calculations were wrong, and the Earth must be smaller - which led him to seek India in the west.