A light source is defined as an object that is capable of emitting light radiations or energy into the environment. Light sources can be broadly categorized into two categories, namely natural sources of light and artificial or man-made sources of light. The objects that are capable of emitting light of their own are known as luminous objects. This means that all the sources of light are also known as luminous objects. The sources of light that are naturally available in the environment are typically known as natural sources of light. The properties of light radiations obtained from the natural sources of light such as intensity, speed of propagation, brightness, contrast, etc. can not be varied or controlled externally.
Examples of Natural Sources of Light
There are a number of sources of light that are present naturally on the earth. Some of them are listed below:
1. Sunlight
The light received by the sun is one of the most prominent examples of natural sources of light. The radiations obtained from the sun are easy to access and are available in abundance. The properties of the sunlight such as intensity, direction, the velocity of propagation, brightness, etc. cannot be controlled externally.
2. Lightning
Lightning is a natural phenomenon that occurs due to an imbalance in the charges contained by the ground and the clouds. The negative charges or the electrons that are present in the clouds tend to get attracted towards the positive charges or the protons that are present on the surface of the earth. This creates a quick electrical discharge that helps in the formation of lightning.
3. Animals
Various marine species such as jellyfish, angler fish, viperfish, etc. are considered to be the prime examples of natural sources of light.
4. Plants
A variety of plants including mushrooms are capable of producing light energy into the surroundings. Such plants are typically known as bioluminescent plants and are typically classified under the category of natural sources of light.
5. Insects
Fireflies, glow worms, and various other insects tend to emit light naturally and are yet another example of the natural sources of light present around us.
6. Stars
The stars are one of the best examples of natural sources of light.
