Spanish for "Cave of the Hands," Cueva de las Manos is an Argentinean cave famed for the paintings of hands—along with depictions of humans, animals, hunting scenes, and geometric shapes—that are believed to have been made thousands of years ago by the region's indigenous inhabitants. Based on the size of the hands, it is speculated that teenage boys stenciled them on the wall of the cave to mark their advancement into manhood. Most of the paintings are of left hands, suggesting what?
Back in the day
Among the most recognized and visited structures in the world, the Eiffel Tower was built beside the Seine River in Paris between 1887 and 1889 as the entrance arch for the Exposition Universelle, a World's Fair marking the centennial celebration of the French Revolution. Named after its designer, engineer Gustave Eiffel, the tower was constructed by 300 workers who joined together 18,038 pieces of puddled iron using 2,500,000 rivets. How many people died during the tower's construction?
Born on a day like today
René Descartes was a French mathematician, scientist, and philosopher who is considered the father of modern philosophy. Aiming to apply the rigor of mathematics to philosophy, Descartes sought to subject all knowledge about which it is possible to be deceived—including knowledge based on authority, the senses, and reason—to methodical doubt in order to arrive at something about which he could be absolutely certain. His most famous statement, "Cogito ergo sum," is understood to mean what?