The month of April brings spring showers. After those showers, the sun comes out and a rainbow often appears. Each year on April 3rd, National Find a Rainbow Day challenges us to look to the sky and find a colourful ray of hope cast across it.
A rainbow is a spectrum of light in the form of a multi-coloured arc, appearing in the sky, that is caused by both reflection and refraction of light in water droplets in the Earth’s atmosphere. Rainbows always appear directly opposite of the sun. The light is refracted (bent) when it enters a droplet of water (which acts as a prism), then is reflected inside on the back of the droplet and refracted again when leaving it.
A rainbow has seven colours because water droplets in the
atmosphere break sunlight into seven colours. When light leaves one medium and
enters another, the light changes its propagation direction and bends. Red is
the colour that is visible on the outer part of a rainbow and violet on the
inside of a primary rainbow.
No comments:
Post a Comment