Do you know why the sky is blue? Get ready to answer this question because it is likely that at some point in life you will face it. Have you thought about it? During the day the sky is blue and at night it is black. The scientific explanation is clear and has to do with the refraction of sunlight and its dispersion.
To understand why the sky is blue, we need to understand the nature of sunlight and how it interacts with gas molecules that make up the atmosphere from the earth.
The sky is blue, why?
The sunlight, which appears white to the human eye, is actually a mixture of all the Rainbow colors. For many purposes, sunlight can be thought of as a electromagnetic wave which causes the charged particles (electrons and protons) within the air molecules oscillate up and down when sunlight passes through the atmosphere.
When this occurs, the oscillating charges produce electromagnetic radiation at the same frequency as incoming sunlight, but spread out in all directions. This redirection of incoming sunlight by air molecules is called scattering, according to ScientificAmerican.
Specifically, this physical principle, which is called the Rayleigh scattering, is what gives the sky its color. Rayleigh scattering not only describes the scattering of sunlight from air molecules, but is true for all forms of light. electromagnetic radiation and for all particles that are much smaller than the wavelengths of the radiation in question, according to InvestigaciónyCiencia.es.
The intensity of the light scattered by these particles is proportional to the inverse of the fourth power of the wavelength of the light: therefore, the shorter the wavelength, the more the radiation will be scattered.
The blue component of the visible light spectrum has shorter wavelengths. and higher frequencies than the red component. Thus, when sunlight of all colors passes through the air, the blue part causes charged particles to oscillate faster than the red part.
The faster the oscillation, the more scattered light is produced, so blue is scattered more strongly than red. For particles, such as air molecules, that are much smaller than the wavelengths of visible light, the difference is dramatic. The acceleration of charged particles is proportional to the square of the frequency, and the intensity of the scattered light is proportional to the square of this acceleration.
The intensity of scattered light is therefore proportional to the fourth power of the frequency. The result is that blue light is scattered in other directions almost ten times more efficiently than red light.
RESUME: Light from the Sun reaches the Earth’s atmosphere and is scattered in all directions by gases and particles in the air. Blue light spreads out more than other colors because it travels in shorter, smaller waves. This is the reason why we almost always see the sky as blue (NASA educational website.)
When we look at any point in the sky, away from the sun, we only see light that has been redirected by the atmosphere towards our line of sight. Since this occurs much more often in blue light than in red, the sky appears blue. Actually, violet light scatters a little more than blue. However, more of the sunlight entering the atmosphere is blue than violet, and our eyes are somewhat more sensitive to blue light than violet, so the sky appears blue.
Why does the sky change color
The sky is not always blue or the same blue and sometimes we see it orange or reddish. And it is that, as the Sun approaches the horizon, light must pass through an increasing portion of atmosphere and the color of the light darkens because the short wavelengths (associated with the colors blue or green) disperse, leaving only the longest wavelengths.
Source: Lasexta
Paul is a talented author and journalist with a passion for entertainment and general news. He currently works as a writer at the 247 News Agency, where he has established herself as a respected voice in the industry.
