Through the looking glass

In December 2013, the 68th Session of the UN General Assembly proclaimed 2015 as the International Year of Light and Light-based Technologies (IYL 2015). Thus 2015 is a great year to begin, or add to, activities about light that can be conducted in a classroom.

Here are two articles on optics where we look at some history and then get down to some experiments to understand the basic ideas behind light.

History of science through an optical lens

Pinaki Das

rectilinear-propagation-and-the-law-of-reflection Why history of science
Textbooks usually present science as a “finished product” rather than as a “work in progress”. How did the ideas take shape? What were the contending theories? These are never discussed. An important part of learning is to learn how others have thought about the problem. Thus history of science seems to me to be an integral part of the teaching of science. I have delved into the history of science looking for the “connections” which are sadly missing from our textbooks. Here I present some random notes in the history of the development of optics.

Learning principles of optics through simple experiments

HC Verma

light-2 Light has been my favourite topic all-time. While humans, animals, and birds directly use light to experience the thrill of this wonderful world, even plants look to light for their survival and growth through photosynthesis.

At school level we are told mostly about four major behaviours of light.
• It moves in a straight line making shadows of obstacles in between
• It reflects from smooth surfaces allowing us to comb our hair in front of mirrors
• It refracts allowing us to make cameras, telescopes, and microscopes
• It comes with different colours making things look colourful and making beautiful rainbows

Pinaki Das teaches physics at Vidyaranya High School for Boys and Girls, Hyderabad. He can be reached at

HC Verma is professor of physics at IIT, Kanpur and an all time physics student. He can be reached at

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