Sunlight is one of the key factors responsible for nurturing life on earth. One of the simplest definition of sunlight is the “light that comes from the Sun”. Sometimes, it is also referred to as “solar radiation” or “sunshine”.
Wavelength of Sunlight
Infrared, Visible Light and Ultra Violet — are the electromagnetic waves which form part of the sunlight. All three major components of sunlight have different wavelengths. Out of the three electromagnetic waves, only visible light is detectable to the human eyes.
|Ultraviolet||Shorter than 0.4 micrometre|
|Visible Light||0.4 and 0.8 micrometre|
|Infrared||Longer than 0.8 micrometre|
What is the Color of Sunlight? Is it White or Colored?
Have you ever gone out on a bright sunny day and dared to look at the sun? Well, we all have done that as children. Now, recall that experience – what was the color of the sunlight? Wasn’t it white?
Most of us will answer confirming the color of sunlight as white. However the truth is that the white sunlight is actually very colorful! Confused?
Let’s understand it more deeply. The sunlight appears white to human eyes. However, the white sunlight consists of a band of seven different colors mixed together in sequence.
You can understand this concept with the help of a glass prism. When a single beam of sunlight passes through a glass prism, the white sunlight splits into seven different colors.
The phenomenon of splitting up of white sunlight into seven different colors on passing through a transparent medium is called dispersion. In our case, the transparent medium was the glass prism. The formation of this band of seven different colors shows that the sunlight that appears white to our eyes, is in fact made up of seven colors.
It is because of these colors we are able to see different things. If sunlight didn’t consist colors, everything would appear of the same color. An object appears green to us because it reflects the green colored light and absorbs all other colors. If an object would absorb all the colors, it would appear black to us.
What is VIBGYOR?
VIBGYOR is the acronym used for the band of seven different colors in the white sunlight. Sunlight consists the following seven colors:
|V – Violet||I – Indigo||B – Blue||G – Green||Y – Yellow||O – Orange||R- Red|
How does a rainbow form?
Formation of the rainbow is a natural phenomenon. Dispersion of light is the scientific reason behind the formation of the rainbow. Rainbow is usually formed when rain is immediately followed by a bright sun in the sky.
Raindrops which remain suspended in the atmosphere act as prisms and dispersion of sunlight takes place through these raindrops. This leads to scattering of white sunlight into seven different colors. We, thus, see a beautiful rainbow in the sky!
Important Facts About Sunlight
- From the surface of the sun, light takes approx. 8.3 minutes to reach our Earth.
- Sunlight is the main factor behind the mechanism of photosynthesis. Photosynthesis is a process by which light energy is converted into chemical energy in green plants and other autotrophic organisms.
- Not all places on Earth receive the same amount of sunlight in a given period. While some places near-equatorial region receive around 4000 hours of sunlight per year, places near Earth’s poles experiencing frequent storm and cloudiness receive around 2000 hours of sunlight yearly.
- Ultra-violet radiation of sunlight produces Vitamin D3 in our bodies. Ultraviolet rays are also mutagen.