What Is Light Energy?

Light consists of small packets of energy called photons. Light energy is a form of electromagnetic radiation and is the only form of energy visible to the human eye. Light energy travels in waves and is very fast.

The sun, stars, lamps, lasers, and hot objects are examples of light energy. The sun emits large amounts of electromagnetic radiation. Humans, on the other hand, can only see a small fraction of this energy, called visible light. The light energy we obtain using the sun, fire or electricity helps us see objects and our environment.

Light energy travels at a certain wavelength and carries a certain amount of energy. The amount of energy of a wave is indicated by its wavelength, which is the distance between successive points of the wave. The longer the wavelength, the less energy is transported. Short wavelength (tight waves) means more energy. The reason why light is seen in different colors is that each color has a different wavelength.

Light appears only when there is an object to reflect. When light hits an object, it can be reflected, absorbed, or transmitted. When light enters a new medium at a certain angle, it is refracted or bent.

Visible light usually falls in the range of 400-750 nm (nanometers). Infrared, ultraviolet and x-rays are outside this range. The wavelength of the light determines the perceived color. For example; The range 450-500 nm means blue, the range 500-570 nm means green, the range 570-590 nm means yellow, and the range 620-750 nm means red light.

Different materials absorb and reflect different wavelengths (colors) of light. For example, a blue shirt absorbs all wavelengths except blue, reflecting blue. A black object absorbs all wavelengths, while a white object reflects all wavelengths.

Plants also capture the light energy from the sun and use it for growth. Blue and red wavelengths are the two wavelengths at which chlorophyll absorbs visible light most effectively. Plants reflect most of the green light, which causes us to perceive them as green.

When you look at a tree outside on a sunny day, what you see is not the tree, but the sunlight reflecting off the tree and entering your eyes.