Solar system: Did you mean...?

The alliance system in Europe was one of the causes of the First World War (1914-18), although it did not make war inevitable. In the first decade of the 20th century, the Triple Entente powers...

The term "Athenian Calendar" (also called the "Attic Calendar") has become somewhat of a misnomer, since Ancient Athenians never really used just one method to reckon the passage of time. Athenians, especially from the 3rd...

The Babylonians developed a calendar based on the moon and sun cycles. The Lunar calendar was designed to work in conjunction with the solar cycle by adding leap months known an "intercalary" months.

The repartimiento system was a distribution of rights to Spanish colonialists and municipalities, which allowed them to extract forced but low-paid labour from local communities in conquered territories. Designed to replace the...

Ra (also given as Re) is the sun god of ancient Egypt. He is one of the oldest deities in the Egyptian pantheon and was later merged with others such as Horus, becoming Ra-Horakhty (the morning sun), Amun (as noonday sun), and...

This infographic illustrates the Varna caste system in ancient India. First mentioned in the Rig Veda's Purusha Sukta c. 1200–1000 BCE, it shows society divided into four groups that emerged from the...

This infographic illustrates the Dowding System, Britain’s groundbreaking air defense network that played a critical role in winning the Battle...

Smugglers in 1808, defying the Continental System. Etching by John Augustus Atkinson and William Miller, 1808. National Maritime Museum, Greenwich, London.

In Norse mythology, the Sun and the Moon appear as personified siblings pulling the heavenly bodies and chased by wolves, or as plain objects. Written sources, such as the Poetic Edda and the Prose Edda, have surprisingly...

The Shushtar Hydraulic System is a Sasanian era (3rd century CE) water irrigation system in Shushtar in Iran that included watermills, dams, tunnels and canals. The mills, one of which is still functioning, were used...