Caste System: Did you mean...?

An illustration of the solar system by Martin Kornmesser. From The International Astronomical Union.

The underground channel of a qanat in the Turfan water system in the Turpan Depression of Xinjiang, China.

A photograph of part of the tunnel network of the Maginot Line, the defensive system built along France's eastern frontiers prior to the Second World War (1939-45). From the Schoenenbourg fort, Bas-Rhin, France.

Intercultural referral model used in Dino Stagno Hospital, Traiguen, Chile.

The Achaemenid Persian Empire functioned as well as it did because of the efficient bureaucracy established by its founder Cyrus the Great (r. c. 550-530 BCE) which was administered through the satrapy system. A Persian...

Chandragupta Maurya (c. 321 - c. 297 BCE), known as Sandrakottos (or Sandrokottos) to the Greeks, was the founder of the Maurya Dynasty (4th-2nd century BCE) and is credited with the setting up of the first (nearly) pan-Indian...

The Arthashastra is an Indian treatise on politics, economics, military strategy, the function of the state, and social organization attributed to the philosopher and Prime Minister Kautilya (also known as Chanakya, Vishnugupta...

Vardhamana (l. c. 599-527 BCE), better known as Mahavira (“Great Hero”) is the sage credited with founding of the nontheistic religion of Jainism, a belief system established in the 6th and 5th centuries BCE in India, which provided...

In recent years, a persistent criticism has been leveled against the use of the BCE/CE system (Before the Common or Current Era/Common or Current Era) , rather than BC/AD (Before...

View full lesson: https://ed.ted.com/lessons/how-the-world-s-first-subway-system-was-built-christian-wolmar It was the dawn of 1863 CE, and London's not-yet-opened subway system — the first...