light

Home » light » Page 2

Roger Bacon – Medieval science

By |2018-04-24T08:21:21-07:00August 4th, 2017|Medieval, Science|

Roger Bacon's diagram of a human eye Roger Bacon was born in England maybe about 1210 AD. It was late in the reign of King John. (That's the one in Robin Hood.) England was just beginning to get richer from raising and selling high quality wool cloth on the Silk Road. In addition, a warmer climate - the Medieval Warm period - was making [...]

Sine waves – trigonometry – math

By |2017-07-29T17:59:39-07:00July 29th, 2017|Math|

Sine wave In order to save energy, many, many things in nature move in a kind of repeated pattern we call a sine wave: water waves, sound waves, light waves, electricity, radio waves, and microwaves, for instance. The waves move in one direction quickly, then slow down until they stop, and begin moving [...]

Medieval Islamic science

By |2018-04-24T08:21:20-07:00July 27th, 2017|Islam, Science|

Al Tusi's diagram of linear motion from circular motion In the Early Middle Ages, before the formation of the Islamic Empire, Buddhists ran the world's biggest universities. One was in India, at Nalanda. Another was in what is now Pakistan, at Taxila. In Egypt, the University of Alexandria was still an important center of learning, too. Most serious scholars went to [...]

Ibn al-Haytham – Medieval Islamic science

By |2018-04-16T10:32:27-07:00July 27th, 2017|Islam, Science|

Diagram of an eye, by Ibn al-Haytham (ca. 1000 AD) Ibn al-Haytham was born about 965 AD in Basra, near the Persian Gulf (modern Iraq), and when he grew up he went to Cairo, then a rich university center under Fatimid rule, and became a scientist. Al-Haytham first worked on a plan to build a dam across the Nile [...]

Medieval Islamic astronomy

By |2018-04-23T10:04:24-07:00July 27th, 2017|History, Islam, Science|

Islamic astronomers taking observations West Asian astronomers had been world leaders in astronomy for thousands of years before the Islamic conquests in the 600s AD. In the last centuries BC, West Asian astronomers had already figured out that the earth was a ball, and that the earth went around the sun, and how big the earth was, and that the moon went [...]

al Tabari – Medieval Islamic medicine

By |2019-01-21T08:34:19-07:00July 27th, 2017|Islam, Science|

al Tabari's homeland in Tabiristan Where did al Tabari come from? Al Tabari was from a Christian family in the Abbasid Empire, near the Caspian Sea (modern Iran). His father, Sahl, was himself a doctor who proposed a new treatment for epilepsy. More about Islamic medicine What was the Abbasid Empire? All our Islamic Empire articles [...]

Who is Lakshmi? Hindu goddess – India

By |2017-07-21T11:07:45-07:00July 21st, 2017|India, Religion|

Lakshmi (Sanchi Stupa, central India, 200s BC) Lakshmi was (and is) a Hindu goddess of light, wealth, good luck and success. Her name comes from the Sanskrit word laks, which can mean "light" or "goal". And that comes from an earlier Yamnaya word for "bright and shiny". There are statues of Lakshmi starting about 500 BC, but she probably became a [...]

Diwali – the Festival of Lights – Hinduism – India

By |2017-07-21T08:36:06-07:00July 21st, 2017|India, Religion|

Flowers and Diwali lamps Diwali is a Sanskrit word originally meaning "a row of lights" - "dipa" is the Sanskrit word for "light". Diwali is an Indian harvest festival celebrating the end of the hard work of harvesting food. People celebrate that now there is plenty of food to last through the winter. Hindus, Buddhists, and Jains all celebrated Diwali [...]

Who was Euclid? History of Geometry

By |2018-04-23T14:03:16-07:00July 18th, 2017|Africa, Egypt, Science|

An Egyptian papyrus from about 100 AD which is a piece of one of Euclid's books Nobody knows much about Euclid's life anymore - it is all forgotten. We only know that he worked at the University of Alexandria, in Egypt, for a while. There are no pictures of him. We can't even be sure [...]

Ancient Greek astronomy

By |2018-04-23T14:17:22-07:00July 18th, 2017|Greeks, Science|

Eclipse of the sun The art of astrology, the study of the stars in order to predict future events, and to interpret people's characters, was already very advanced before the Greeks began to interest themselves in the stars. The Egyptians and especially the Mesopotamians had done a lot of scientific observations and had named the constellations of stars, and [...]