This book describes a number of simple methods for showing that light is polarised and determining the direction of vibration. It is based on a demonstration lecture, called 'Polar Explorations in Light' developed for young audiences, at the Royal Institution of Great Britain.

We humans cannot see when light is polarized and this leads to unfortunate misapprehensions about this aspect of nature. Even scientists who should know better often assume that it is an obscure topic of specialized interest in only a few rather isolated areas. In fact, it is a universal feature of our world and most natural light is at least partially polarized. In the animal kingdom, insects and other animals exploit such natural polarization in some fascinating ways since they do not share this human deficiency and can both detect and analyze polarization. It may be our unfamiliarity with this aspect of light that also makes people think it is a difficult subject, yet the basis is extremely simple. When these misconceptions are overcome, the phenomena associated with polarization are found to be important throughout science and technology, from physics, astronomy, natural history, geology, chemistry, and several branches of engineering to crafts such as glass-blowing and jewelry. Polarized light also involves some very beautiful effects, most of which are easy to demonstrate.
Enriching our perception of the world, this book addresses these misconceptions and provides a framework for applications. It covers wave alignment and crystals as well as various phenomena such as scattering and reflection.