Modern flat Earth societies are organizations that promote the misconception that the Earth is flat rather than a sphere. Such groups date from the middle of the 20th century; some adherents are serious and some are not. Those who are serious are often motivated by pseudoscience or Biblical literalism. Through the use of social media, flat Earth theories have been increasingly espoused by individuals unaffiliated with larger groups, many of which have members from several countries. Modern flat Earth hypotheses originated with the English writer Samuel Rowbotham (1816–1884). Based on conclusions derived from the Bedford Level experiment, Rowbotham published a pamphlet Zetetic Astronomy. He later expanded into a book Earth Not a Globe, proposing the Earth is a flat disc centred at the North Pole and bounded along its southern edge by a wall of ice, Antarctica. Rowbotham further held that the Sun and Moon were 3,000 miles (4,800 km) above Earth and that the "cosmos" was 3,100 miles (5,000 km) above the Earth. He also published a leaflet titled The inconsistency of Modern Astronomy and its Opposition to the Scriptures, which argued that the "Bible, alongside our senses, supported the idea that the earth was flat and immovable and this essential truth should not be set aside for a system based solely on human conjecture".