0.13 Chapter 4.light and matter – dielectric behaviour of matter

Chapter 4.Light and Matter – Dielectric Behaviour of Matter [“OPTICS” by Eugene Hecht, IIIrd Edition, Addison-Wesley-Longman Incorporation, Readings, Massachsetts].

Section 4.1. Brief History of Scientific and Technological Development in the field of Light.

Study of Light and its application in Human Society can be traced back to 1200 BCE. In Exodus 38.8 (a chapter in The Bible) we find the mention of “Looking Glass of the Women”. Early mirrors were made of polished copper and bronze. Evidence of the use of mirrors turned up in excavations of the workers’ quarters near the construction site of Pyramid during the ancient Egyptian Civilization. At that time it was made of Speculum – a copper alloy rich in tin. In Roman Civilization we find the use of convex lens as Magnifying Glass as well as Burning Glass.

After 475CE, with the fall of Western Roman Empire, dark ages descended in Europe and the center of Scientific Enquiry shifted to the Arab World. Islamic scholar Abu Ali al-Hassan Ibn al-Haytham (CE. 965-1041), known in the West as Alhazen, began his career as just another Islamic polymath. He was put in House Arrest by Al-Hakim, the Calipha of Cairo, because he failed to regulate the flow of Nile river. While in House Arrest for 10 years, Alhazen revolutionized the study of optics and laid the foundation for the scientific method. (Move over, Sir Isaac Newton.) Before Alhazen, vision and light were questions of philosophy. Alhazen considered vision and light in terms of mathematics, physics, physiology, and even psychology. In his Book of Optics , he discussed the nature of light and color. He accurately described the mechanism of sight and the anatomy of the eye. He was concerned with reflection and refraction. He experimented with mirrors and lenses. He discovered that rainbows are caused by refraction and calculated the height of earth’s atmosphere. In his spare time, he built the first camera obscura .

From 1000 CE to 1600 CE, there was only a modest revival of Scientific Enquiry and Research in Europe. The science of vision error correction by the use of Eye Glasses were introduced. Looking Glass or Mirror Technology was revived by the use of liquid amalagam of tin and mercury coated on the back of glasses. Use of multiple mirros and use of positive and negative lenses were in vogue in this era.

Section 4.1.1. The revival of Scientific Enquiry in 17 th Century in Europe -The Renessaince Period.

Table 1. Time-line of Scientific Research in Application of Light for Human Good.