Science

Look! Listen!

Sound

What is sound?

Sound is produced by tiny, rapid vibrations in the particles that make up materials. This can be air, liquids or solids but not in a vacuum or outer space, which have no particles. When the vibrations reach our ear, our brain translates the signal into what we call sound.

Light

What is light?

Scientists use two models to explain light and its phenomena: the wave model and the particle model. In the wave model, light spreads out in all directions, like a wave, from a source, for example, a light globe. In the particle theory, the light streams from the sourceas fast-moving particles. The term ‘particles’ in this model doesn’t refer to particles of matter but describes photons or ‘packets of energy’.