What are they?
The visible light section is the only portion of the electromagnetic spectrum that is visible to the human eye. It is located between infrared and ultraviolet
It accompanies only a tiny space of the whole spectrum and within it are the colours of the rainbow, which makes up a spectrum of its own called the visible light spectrum. It is divided into 7 main colours, each with their own individual wavelengths starting with red as the longest, then orange, yellow, green, blue, indigo and violet as the shortest.
A prism divides light into wavelengths. When all the colours are combined, white light is seen. When the white light shines onto a prism, the colours in it separate from each other because they refract at different angles depending on their wavelengths. this create a rainbow.
A prism divides light into wavelengths. When all the colours are combined, white light is seen. When the white light shines onto a prism, the colours in it separate from each other because they refract at different angles depending on their wavelengths. this create a rainbow.
Light can be easily absorbed, reflected and refracted, depending on the object and the substance it is made from.
All objects, living or non-living are capable of absorbing light. Though their chemical structures allow certain frequencies of the spectrum to be absorbed and others reflected. This property gives objects their colour. For example, green plants contain a pigment called chlorophyll which absorbs all colours, but reflects green light, so we see the plant as green coloured. If an object absorbs all frequencies of light, it will appear black. As it absorbs all this energy, it will get hotter faster. This is why dark coloured objects are hotter than light coloured objects. |
When light is reflected, it allows us to see images in mirrors and colours on objects.
The refraction of light occurs when light is 'bent' when it passes from one medium to another because of different densities in the material. This is because light travels at the 'speed of light' which is known as the fastest speed possible, though things which block its path can slow it down. The greater the difference in density, the more light appears to bend. An example of this effect is when a straw appears bent in a clear glass of water, because water is more dense than air. Refraction is also applied in magnifying glasses, microscopes and glasses (lens).
The refraction of light occurs when light is 'bent' when it passes from one medium to another because of different densities in the material. This is because light travels at the 'speed of light' which is known as the fastest speed possible, though things which block its path can slow it down. The greater the difference in density, the more light appears to bend. An example of this effect is when a straw appears bent in a clear glass of water, because water is more dense than air. Refraction is also applied in magnifying glasses, microscopes and glasses (lens).
In Communications.
Light has the highest information carrying capacity of all the communication systems. The frequencies of light are the highest available for practical communication systems.
In communications technology, light is used in optic fibres to transmit information as a form of light pulses. A concept called 'total internal reflection' is applied to trap the data-containing light across the fibre. As light travels inside, it bends and reflects so much that instead of getting lost through absorption, it is reflected along a passage until reaching its destination. In this way, light travels very quickly down the fibre optic cable over long distances with less interferences and loss of data. this makes it more preferable than copper networks.
In communications technology, light is used in optic fibres to transmit information as a form of light pulses. A concept called 'total internal reflection' is applied to trap the data-containing light across the fibre. As light travels inside, it bends and reflects so much that instead of getting lost through absorption, it is reflected along a passage until reaching its destination. In this way, light travels very quickly down the fibre optic cable over long distances with less interferences and loss of data. this makes it more preferable than copper networks.