Light Sources

Light Source - Types of Light Sources

There would be no world if lights were not there as light providing us the ability to see things. Plants also need light which is provided by the sun in the form of sunlight through which many processes in nature takes place, so we can say that the main source of light on earth is sunlight. Light comes from different sources which are known as light sources, and these light sources can be defined as the sources through which light (a form of energy) is produced. Light is an energy source which can travel as a wavelength and can travel very quickly. Rainbow formed in the air is the very common example of light striking the droplets of water to separate colors with different wavelengths, making our eyes to see those different wavelength colors forming the rainbow. We can say that the light is a form of electromagnetic radiation, whose particular particle can produce radiation of around 390 – 700 nm which is visible with a human eye. The human eye can see almost all types of light except for infrared and ultraviolet rays. Our brain further process the light captured by our eyes, translating the energy bandwidth into the color spectrum our brain and eyes are sensitive to. The artificial life created by humans is formed by the movement of molecules (rational as well as vibrational) having the transitions with molecules or atoms. An atom or molecule gets excited and enters a state which is considered as absorbing, while it can be said as entering an emitting state when these atoms or molecules relaxes. If the light is in any other form of electrical energy then these electrical energies can be easily converted into light energy.

Basically, we can say that by exciting energy with any means necessary at that particular region then it is said to be light, as the light lies in the visible spectrum in the form of energy or wave. In the modern world, humans are also creating artificial light, which is the most suitable form of the electrical energy in the current world. Neon lights, light bulbs and fluorescent tubes are very good examples of electrical light. Lasers are also a good example of artificial light.

Types of Light Sources 


There are numerous sources of light which fall in different categories. They can be differentiated into either of the following: 


·   Natural light sources  
·   Artificial light sources
.   Incandescent light sources 
.   Luminescence light sources 

  Natural light of sources 

Basically, we all are aware of the fact that light is a form of energy that is produced from different sources. Our universe is filled with the object that gives light with the help of natural things present around us. There are countless things that are naturally generated through which we get light. The following are the things in nature that have the ability to let us enjoy our life due to light. 
      
Sun - The major and most imperative source of light on the earth is Sun. The sun is the only natural source that is a massive ball of fire in which nuclear fusion produces a large amount of energy at the centre. Sun is the major factor behind the light on the earth which produces heat as well. 
  
Star – The star is the other factor that produces light even though the amount of quantity that reaches the earth is small.  


Moon – Moon is also one planet that gives light as well but not of its own. The light that the moon gives is the light reflected from the sun because the moon does not have its own light. Apart from these sources of light, some of the living organisms have the ability to produce light as well and that organisms are called bioluminescence. Basically, bioluminescence is the effect of certain chemical reactions within the organisms. Some of the examples are fireflies, glow worm, jellyfish, certain deep-sea plants and micro-organisms.

Artificial light of sources:


Artificial light is made up of advanced technology that resembles natural light (sunlight). For example: bulbs, tube lights. Artificial light is developed at the end of 19th and beginning of the 20th century. There are two ways to measure natural light i.e. the specific frequency range and the strength of illumination that measure in lumens. Artificial Lights can easily be seen around you. Peoples usually use artificial light at a wide scale in their homes, at commercial places and many other places. These are available at large variety like in shapes, sizes, colours and even in level of brightness.

Incandescent light source


An incandescent light source is the most common type of source in which sun, light bulbs and fires can be included. Incandescent light is a type of light source which includes the vibration in the entire atom, as when the atoms are heated then the thermal vibrations in the form of electromagnetic radiations are released. Depending on the temperature the materials vary in emitting energy, at low temperature of the materials, the emittion of radiation takes place through infrared wavelength in the photons. A common example of incandescent light source is when a metal is heated, the atoms present in the metals gets vibrated and emit photons which emit radiations to make it visible to the human eye by raising the wavelength in the spectrum.

Fire is the most common example of incandescent light, as fire includes chemical reaction which releases both gases and heat making the material to reach a high temperature, causing the material and gases incandescent (lighten up).
Similarly, light bulbs produce heat through which electrical current passes raising the temperature of the cable and finally providing incandescent to the cable.

Luminescence light source:


As compared to incandescent light sources, these types of sources involve only electrons instead of the whole material vibrations, which takes place in normal or lower temperatures making it different from the Incandescent type of sources. Basically, we can say that when the electrons emit some part of its energy in the form of electromagnetic radiations then the type of light is known as luminescence light. When an electron drops down in temperature then the specific light color is produced through the energy level decrement. Some common examples of Luminescence light source are neon lights, fluorescent light, bioluminescence, fluorescence light, etc. Fluorescence light is the most common example of luminescence light source which can be further divided into two parts which are electro-luminescence and photo-luminescence which can include computers screens and televisions. Bioluminescence is also the most common example of luminescence which even includes animals like fireflies.

Difference between Natural Light and Artificial Light


The most important difference between natural light and artificial light is that natural light can be found in nature but artificial light are electronic which is formed with the help of advanced technology. Natural light has no control over the usage as it is based on the duration of time but this is not in the case of artificial light. Usage of artificial light is limited. The amount of light produced is the main factor of using artificial light. If the artificial light is produced in less quantity then the consumption is also low.