Nicolaus Copernicus proposed the heliocentric model in 1543, stating Earth revolves around the Sun, challenging geocentric beliefs.

The Ming dynasty expanded and fortified the Great Wall between the 14th–17th centuries, much of which still stands today.

The Panama Canal, opened in 1914, links the Atlantic and Pacific Oceans, greatly reducing shipping time between east and west.

Montesquieu in *The Spirit of Laws* (1748) emphasized separation of powers, inspiring modern democratic constitutions like the US.

The Inca used quipus, knotted strings, as a method of recording numbers and information without writing.

The Sumerians developed cuneiform around 3200 BCE in Mesopotamia, marking the first recorded writing system in human history.

Dmitri Mendeleev organized the periodic table in 1869, predicting properties of undiscovered elements.

The Great Depression began with the US stock market crash of 1929, leading to global economic hardship throughout the 1930s.

Marie Curie, with Pierre, discovered radium and polonium in 1898, pioneering radioactivity research and earning two Nobel Prizes.

Russia is the largest country by land area, spanning Eastern Europe and northern Asia across eleven time zones.