The Reason Behind Stars Flickering
Stars actually won’t flicker; we perceive it like that.
Twinkle Twinkle Little Star is the very first and most lovable rhyme to me.
Do you ever wonder why the stars twinkle? If so, did you think a few stars wouldn’t flicker?
Come on, I’ll tell you.
Celestial bodies, which have their heat and light, are called stars. The planets don’t produce any light; they just light up by reflecting the light from the stars.
Now, coming to the twinkling stars, the stars do twinkle because light from the stars needs to travel a long journey from the earth’s atmosphere to the earth’s surface to reach our eye.
In this journey, some modifications are made to the straight traveling light.
Earth’s atmosphere is composed of five layers, based on temperature variation.
So while the light is on the journey, its route is slightly bent multiple times through the layers, as the layers have different temperatures and different composition properties.
Due to this, there is a change in light’s speed and direction.
This is called the refraction of light. When light travels from one transparent medium to another, it undergoes refraction.
So when we observe this light, the stars appear to twinkle, but they do not.
A similar thing can be observed in the water coin experiment that we did in school.
And wait, it’s not over yet.
Why do only a few of the stars flicker?
The reason is that when the stars are too far away and on the horizon, they don’t undergo much refraction because there is no need to travel longer to reach Earth. And the brightness decreases for the far stars, so even when they refract, we can’t observe clearly.
This is why planets won’t flicker, as they are not very bright.
If the stars are present near the horizon, then it has to travel more to Earth’s atmosphere where it undergoes more refraction, so it flickers more.
So that’s the catch: only brighter horizons near stars appear to twinkle.
See you soon.
Let me watch the sky I’m feeling bored.
