The rainbow is a natural phenomenon which has delighted people for thousands of years. Most cultures consider the rainbow with affection; it is usually associated with beauty and peace.


We start the workshop by looking at various pictures of rainbows from history and art and consider some of the features of rainbows, such as:


  •   The rainbow we see is part of a circular arc;

  •   We can often see two rainbows;

  •   There is always the same order of colours in a rainbow.


We show geometrically how a rainbow is formed and discover many of the properties of rainbows. We then look at other patterns and shapes from circles and stars, drawing with geometrical instruments and measuring how close our angles are to the expected values.


We shall finish with another few slides of more unusual phenomena in the sky.



PRIMARY: simple demonstration of reflection and refraction, geometrical construction of a ray of light through a raindrop following the ideas of Isaac Newton.


SECONDARY: plus deeper understanding of reflection and refraction and geometrical construction.


SIXTH FORM: plus the use of calculus to predict the position of the primary and secondary bows.


Copyright Maths Discovery 2015