Optics

Optics is the branch of physics that studies light, how it behaves and how it interacts with matter. Light is a form of electromagnetic radiation that travels extremely fast, reaching about 300,000 kilometres per second in a vacuum. When light meets an object, it may be reflected, absorbed, transmitted or bent as it passes from one material to another.

This bending is called refraction and explains why a straw appears bent in a glass of water. White light also contains many colours, which can be separated when different wavelengths are refracted by different amounts, as happens in a prism or in a rainbow formed by sunlight and raindrops. The principles of optics are used in countless everyday technologies.

Lenses in glasses help correct vision by focusing light properly onto the retina, while cameras, microscopes and telescopes rely on carefully designed optical systems to produce clear images. Optical fibres carry pulses of light over long distances, allowing high-speed internet and modern communication networks to operate efficiently.

Scientists also use lasers, which emit highly focused beams of light with specific wavelengths, in medicine, manufacturing, scientific research and many measuring instruments. By understanding how light travels and interacts with different materials, optics has become one of the foundations of modern science and technology.