Good! Although I wanted you to explain what the Doppler effect is. Your turn anyway.Blue; wavelength decreases due to Doppler shiftAll right, my question killed the marathon, so I'll just post the answer.1) Fill in the blank: Stars moving toward us appear more _ (color).If the refractive index of the lens > 1.33: The focal length increases. If the refractive index of the lens = 1.33: The lens becomes invisible. If the refractive index of the lens < 1.33: The lens becomes diverging.
2) Why is this?