Alright buddy, this time we will discuss about Definition and Function of Light, let’s just gouk into the discussion mate.
Light is a form of energy that is needed by living things on earth directly or indirectly for efficient survival.
Judging from the field of physics, there are various opinions of experts regarding the definition of light. One of the ideas of Newton, he said that light is a small particle emitted by the source in all directions at a very high speed. Newton’s opinion is very contrary to the idea of ​​Huygens who said that light is a wave as well as sound. The two ideas are contradictory because it is impossible for light to be both a wave and also called a particle. However, even so each idea has advantages and disadvantages that contribute important meaning to a more precise understanding of light.
Along with the development of the times in a more advanced direction, it has been agreed that light is referred to as “wave-particle dualism”. The term arises when two properties of light are shown together which include, (1) light is energy in the form of electromagnetic waves that are visible to the eye with a wavelength of about 380-750 nm, but can also be invisible at certain wavelengths, (2 ) light is a packet of particles called photons. Photons are quantum electromagnetic fields that interact with electrons and atomic nuclei and are responsible for many forms of matter, such as the existence and stability of atoms, molecules and solids.
If an object can emit its own light, then the object is called light source. For example: sun, flashlight, stars, lights, candles, and so on. Objects that do not emit light are called dark objects.
Light is one of the main sources of energy needed by living things on earth. Here are some of the functions or uses of light.
Without light, humans cannot see anything, because nothing reflects the object seen so that nothing is interpreted in the path of vision.
Utilization of sunlight in heating the roomn consists of several techniques, in including:
  • Window, This principle is applied by making holes in the walls to transmit solar heat from outside into the building. To get optimal heat, it is better to install double glazing on the windows. Although there are also windows without glass which are also widely used.
  • Trombe Wall, dInding trombe is a wall that is usually in the form of glass outside of which there is a narrow space filled with air. Utilization of sunlight is to provide heat to the outdoor surface, then the heat is slowly transferred into a narrow room. Furthermore, the heat in the narrow room will be convec- ted into the building through the air duct on the trombe wall.

The solar stove is a method that utilizes a large concave mirror to absorb heat from sunlight that has previously been focused on a single point. This principle will generate a large amount of heat that can be used to replace the heat from an oil or wood-burning stove. In addition, the need for fossil energy and electrical energy for cooking can be reduced.
4. Agricultural Product Drying
Direct sunlight can dry agricultural products, if agricultural products are dried in the hot sun. This principle is mostly practiced by farmers in the tropics, while farmers in four seasons areas tend to have to use ovens that use fossil fuels or use electricity to dry their agricultural products.
The principle of heating water with the help of sunlight is the absorption of sunlight by the collectors contained in the water pipe. So the water temperature increases. This water then goes into the heat storage. In the heat storage, the heat from the water will be transferred to another water-filled pipe which is the water supply for bathing/antiseptic. Meanwhile, the water coming from the collector will be turned back to the collector using a pump or simply using the thermosiphon principle. The collector used is a flat plate solar collector whose top is made of dim black glass while the bottom is made of good insulating material so that the heat absorbed by the collector is not released into the environment. Hot water in the collector can reach 82 C while the hot water produced depends on the desire because the system is equipped with a temperature controller.
The function of light as a power plant is the use of sunlight (sunlight is converted into electrical energy) to supply electrical power in communication satellites through solar cells. Solar panels will get electrical energy from sunlight by placing a solar panel equipped with a controller (trying that the sun always falls perpendicular to the panel) in a static position facing the sun. Although the actual function of sunlight can be replaced by an electric generator, due to the pollution effect of the use of high electricity generators, the use of electric generators is not recommended.
Plants use sunlight to carry out photosynthesis so that they can maintain their own nature, namely autotrophs (can produce their own food).
In the medical field, light waves from sunlight are used in X-rays. X-ray is an important supporting examination to diagnose a disease in medical science.
Apart from the functions of light that have been mentioned above, there are many more functions and uses of light that are being studied by researchers. In essence, light is very important for the survival of life on earth by all living things.

This is the end of our discussion about Definition and Function of Light, hopefully useful for all of you and don’t forget to leave a comment, okay? J