Stars twinkle

Stars twinkle due to atmospheric refraction. The correct answer is [A] Due to refraction. As starlight travels through Earth’s atmosphere, it passes through layers of varying temperature and density. These atmospheric layers cause the light to refract, or bend, slightly in different directions. The slight bending of light rays results in the apparent twinkling or shimmering of stars when observed from the ground. This effect is more pronounced when stars are near the horizon, where their light passes through a thicker layer of atmosphere. Option B, reflection, does not cause stars to twinkle as stars do not reflect light like surfaces do. Option C, polarization, refers to the orientation of light waves and does not directly cause twinkling. Option D, scattering, refers to the redirection of light rays in different directions due to particles in the atmosphere but is not the primary cause of star twinkling. Therefore, the twinkling of stars is primarily due to atmospheric refraction (option A), which causes the starlight to bend and fluctuate as it passes through varying atmospheric conditions.