The Earth shoe (also known as the Kalsø Earth Shoe) was an unconventional style of shoe invented in the 1970s in Scandinavia by Danish yoga instructor and shoe designer Anna Kalsø. Its unique Negative Heel Technology design featured a sole that was thinner at the heel than at the forefoot, so that when wearing them, one walked heel-downward, as when walking in sand, with various claimed health benefits.The shoes were introduced in the United States in New York City on April 1, 1970, three weeks before the first Earth Day.The shoes surged in popularity and were prominently featured on The Tonight Show Starring Johnny Carson and in TIME Magazine. When the manufacturer of Kalsø Earth Shoes was unable to keep up with demand, franchise owners pursued litigation against the United States distributor. Retail sales of the brand in the U.S. were discontinued by the late 1970s.In 2001, Kalsø Earth Shoes re-surfaced after the rights to the name, technology and branded properties were purchased by Meynard Designs, Inc.
The Earth shoe (also known as the Kalsø Earth Shoe) was an unconventional style of shoe invented in the 1970s in Scandinavia by Danish yoga instructor and shoe designer Anna Kalsø.

Early modern Europe is the period of European history between the end of the Middle Ages and the beginning of the Industrial Revolution, roughly the late 15th century to the late 18th century. Historians variously mark the beginning of the early modern period with the invention of moveable type printing in the 1450s, the Fall of Constantinople in 1453, the end of the Wars of the Roses in 1487, the beginning of the High Renaissance in Italy in the 1490s, the end of the Reconquista and subsequent voyages of Christopher Columbus to the Americas in 1492, or the start of the Protestant Reformation in 1517. The precise dates of its end point also vary and are usually linked with either the start of the French Revolution in 1789 or with the more vaguely defined beginning of the Industrial Revolution in late 18th century Britain.Some of the more notable trends and events of the early modern period included the Reformation and the religious conflicts it provoked (including the French Wars of Religion and the Thirty Years' War), the rise of capitalism and modern nation states, and European colonization of the Americas.