DEFINITION AND FUNCTION OF LIGHT
Welcome to Science Lovers...
Well buddy, this
time we will discuss the definition and function of light, we just enter into
the discussion.
A. DEFINITION LIGHT
Light is a form of
energy that is needed by living things on earth are directly or indirectly for
survival efficient.
Judging from the
fields of physics, there is a wide variety of expert opinion regarding the
definition of light. One was the idea of Newton, he says that light is a tiny
particles emitted by the source in all directions at a very high speed. The
Newton opinion is contrary to the idea of Huygens who said that light is a
wave just like the sound. Both opposed the idea because there is no light may
be waves at the same time also referred to as particles. However, even so every
idea has advantages and disadvantages that contributed important meaning to the
notion of a more appropriate light.
As the times to a
more advanced, it was agreed that the light is referred to as
"wave-particle duality". The term arises when there are two
properties of light are shown simultaneously which include, (1) light is energy
in the form of electromagnetic waves visible with a wavelength of about 380-750
nm, but can also be invisible to certain wavelengths, (2 ) is a package of
light particles called photons. Photon is a quantum of electromagnetic field
that interacts with the electrons and atomic nuclei imposes responsibility in
many forms of matter, as well as the existence and stability of atoms,
molecules and solids.
If an object can
emit their own light, the object is called a light source. For example: the
sun, flashlight, star, lights, candles, and so on. While the objects which can
not emit light called dark matter.
B. FUNCTION OF LIGHT
Light is one of the
main energy source needed living things on earth. Here are some of the
functions or the use of light.
1. Function Optical
Without light man
could not see anything, because there is no object that reflects the views so
no one interpreted in the pathway of vision.
2. Warming Room
Utilization of solar
light in the room heating consists of several techniques, including:
1. Window,
this principle is applied to make a hole in the wall to carry solar heat from
the outside into the building. To obtain optimum heat better then the window is
installed double glazing. Although there is also a window without glass that is
also widely used.
2. Wall
trombe, trombe wall is a wall of glass outwardly usually there is a small room
filled with air. Utilization of sun light is to provide heat on outdoor
surfaces, then the heat is slowly transferred into a small room. Furthermore,
the heat inside the small room would be delivered into the building through air
ducts in the walls trombe.
3. Stove Sun
Solar cooker a
method that utilizes a large concave mirror to absorb the heat from the light
matahri which previously had focused on one point. This principle will generate
great heat that can be used to replace the heat from the stove oil or firewood.
In addition, the need for fossil energy and electrical energy for cooking can
be reduced.
4. Drying of
Agricultural Products
Direct sunlight can
dry agricultural products, if crops dried in the hot sun. This principle is
mostly done by the farmers of the tropics, while farmers in the region four
seasons tend to have to use an oven that uses fossil fuels or using electricity
for drying agricultural products.
5. Water Heating
The principle of
heating water with the aid of sunlight is the absorption of sunlight by
collectors contained in the water pipes. So the water temperature increases.
This water then goes into heat storage. In the heat storage, heat from the
water will be transferred to another water pipe that supplies water to the
shower / antiseptic. While the water from the collector will be played back to
the collector by using a pump or just use thermosipon principle. Collectors who
used a flat plate solar collector upper part is made of black glass dimmed
while the underside is made of a material that is a good insulator so that heat
is absorbed by the collector is not released into the environment. The hot
water in the collector can reach 82 C, while the hot water is generated
depending on the desire for a system equipped with a temperature controller.
6. Power Generation
Light as a function
of the power plant is the utilization of solar light (sunlight is converted
into electrical energy) to supply electrical power in satellite communications
through solar cells. The solar panels will get electrical energy from sunlight
by placing solar panels are equipped with a controller (seeking sun always
falls perpendicularly panel) with a static position facing the sun. Although
the exact function of sunlight can be replaced by an electric generator, but
because of the effects of pollution, the use of high electric generator
electric generator use is not recommended.
7. Photosynthesis
Plants use sunlight
to perform photosynthesis so as to maintain the properties themselves autotrof
(can produce their own food).
8. Field of Medicine
In the medical
field, the wave of light from the sun is used in x-rays. X-rays are an
important investigations to diagnose a disease in medical science.
Aside from the light
functions mentioned above, there are many more functions and utilization of
light that is being studied by researchers. In essence, light is very important
for the survival of the earth by all living things.
This is the end of
our discussion regarding the definition and function of light, may be useful
for all my friend and do not forget to leave comments below.
