Rainbow

Point the flashlight to the frame full of reflective glass beads. At the right distance and angle you can witness how a rainbow is formed. The rainbow is created by sunrays refracting, reflecting and decomposing in water droplets. As water has different optical properties to air, the light breaks at their interface depending on the refractive index. Inside the droplet part of the light continues in the original direction and part is reflected. White light is broken up into the colour spectrum in a similar way as when it passes through an optical prism. Due to the properties of water and air the rainbow is only visible on the side of the sky opposite to the Sun and only when the Sun is less than 42° above the horizon. In the same way, red is always on the outer side of the arch and violet on the inner side.