why do stars twinkle
Answers
hey...The stars twinkle in the night sky because of the effects of our atmosphere. When starlight enters our atmosphere it is affected by winds in the atmosphere and by areas with different temperatures and densities. This causes the light from the star to twinkle when seen from the ground.
Earth’s atmosphere.
A ray of light from a star follows a straight path while travelling in a vacuum.
When this ray enters the Earth’s atmosphere, it has to pass through several gases (medium) present in the atmosphere. This causes the light to change its direction, also known as refraction.
Refraction:
All these different gases have different refractive index depending on which, it changes the direction of light towards or away from normal.
Since there are various gases present in the atmosphere, the light ray instead of following a straight path, follows a zigzag path. Something like this:
If ray 3 reaches you first and then ray 1 and then ray 2, you would see the star at position 3, then 1 and then at position 2.
This gives you an illusion that the star is moving or twinkling, but in reality, the star never moved from its position.
