light wave 是咩?

Light is a wave which shows all of the properties of waves. (It shows reflection, refraction, diffraction and interference.)

光是一種電磁波，故名光波。光波和聲波相似，能產生干涉、繞射現象。

Light wave is electromagnetic wave (電磁波) in nature, with wavelength (波長) ranges from 400 nm (violet) to 700 nm (red) and a speed of 300 000 km/s. It propagates by mutual induction of time varying electric and magentic fields (時變電場及磁場). Unlike mechanical waves (機械波) like sound wave, the propagation of light requires no medium (介質), and hence light wave can travel through vacuum (真空).

(54 words)