2. Sources Of Light

on

Light is a form of energy and like all kind of energies, it is produced from a source called Light Source. There are countless sources of light but they can all be categorized into two following categories. They are Natural Light Sources and Artificial Light Sources.

Natural Light Sources

The Universe is filled with objects that emit light. Some of the light from these sources reach the Earth. The following things in nature have the ability to emit light.
Image result for light in nature
>> Sun is the major source of light for the Earth. The sun is a massive ball of fire, at the center of which nuclear fusion produces massive energy. This energy comes out as heat and light. The light from the Sun is the one of the major factors behind the sustainability of life on Earth.
Image result for stars
>> Every other stars produces light too, but only a small or no amount of it reaches the Earth because of the large distance of them from us.
Image result for moon
>>The moon provides light as well but it cannot produce light by it own. The light from the moon is the light reflected by it from the Sun.
Image result for fireflies Image result for jellyfish Related image
>> Some living organisms have the ability to produce light by the effect of certain chemical reaction within the organism. This is called Bioluminescence. Fireflies, jellyfish, glow worm, certain deep sea plants and microorganisms can be cited as examples.
Image result for lightning and volcanic eruptions Image result for lightning
>> Certain other natural phenomena such as lightning and volcanic eruptions also emit light.

Artificial Light Sources


Apart from the natural sources, light can be produced artificially too. The different light sources produced artificially can be put under three categories.

>> Incandescent Sources
Image result for incandescent lamp
When certain objects are heated to a high temperature, they begin to emit light. Both heat and visible light is produced in this process.
Eg: Candles, Incandescent bulbs

>> Luminescent Sources
Image result for luminescent lamp
Light can be produced by accelerating charges in a luminescent material. One common way of doing it is by passing current through the material.
Eg: Fluorescent tube lights, Electric bulbs

>> Gas Discharge Sources
Image result for gas discharge lamp
Passing electricity through certain gases at a very low pressure can produce light too.
Eg: Neon lamp, Sodium lamp

Comments

Post a Comment