Prior to the rise of the Internet, no innovation did more for the spread and democratization of knowledge than Johannes Gutenberg’s printing press. Developed around 1440 in Mainz, Germany, Gutenberg’s machine improved on already existing presses through the use of a mould that allowed for the rapid production of lead alloy type pieces. This assembly line method of copying books enabled a single printing press to create as many as 3,600 pages per day. By 1500 over 1,000 Gutenberg presses were operating in Europe, and by 1600 they had created over 200 million new books. The printing press not only made books affordable for the lower classes, but it helped spark the Age of Enlightenment and facilitated the spread of new and often controversial ideas. In 1518 followers of the German monk Martin Luther used the printing press to copy and disseminate his seminal work “The Ninety-Five Theses,” which jumpstarted the Protestant Reformation and spurred conflicts like the Thirty Years’ War (1618-48). The printing press proved so influential in prompting revolutions, religious upheaval and scientific thought that Mark Twain would later write, “What the world is today, good and bad, it owes to Gutenberg.”

2. The Compass

Magnetic compasses may have been made somewhat obsolete by satellites and global positioning systems, but their impact on early navigation and exploration was inestimable. Originally invented in China, by the 14th century compasses had widely replaced astronomical means as the primary navigational instrument for mariners. The compass provided explorers with a reliable method for traversing the world’s oceans, a breakthrough that ignited the Age of Discovery and won Europe the wealth and power that later fueled the Industrial Revolution. Most importantly, the compass allowed for interaction—both peaceful and otherwise—between previously isolated world cultures.

3. Paper Currency

Throughout much of human history, money took the form of precious metals, coins and even raw materials like livestock or vegetables. The inception of paper money ushered in a bold new era—a world in which currency could purchase goods and services despite having no intrinsic value. Paper currency was widely used in China in the ninth century, but did not appear in Europe until the late 1600s. Spurred on by frequent shortages of coins, banks issued paper notes as a promise against future payments of precious metals. By the late 19th century many nations had begun issuing government-backed legal tender that could no longer be converted into gold or silver. The switch to paper money not only bailed out struggling governments during times of crisis—as it did for the United States during the Civil War—but it also ushered in a new era of international monetary regulation that changed the face of global economics. Perhaps even more importantly, paper currency was the vital first step in a new monetary system that led to the birth of credit cards and electronic banking.