Medium - GCSE Physics Definition

In physics, a "medium" refers to the substance or material that allows energy, such as light or sound, to travel through it. Different types of media include air, water, glass, and even solids like metal. The medium can affect the speed and direction of a wave passing through it. For example, light travels slower through glass than it does through air, which is why objects look different when viewed through a glass of water. Understanding these interactions can help explain various physical phenomena, like why we hear echoes or why a straw looks bent in a glass of water.