more water droplets are present in the air after the rain & light refracts when it passes through water droplets -> sound is more easily to be refracted after the wind light is more easily to be refracted after the rain  light is more easily to be refracted after the rain & refracting sound amounts sound to merger into different swimming -> light is more easily to be split into different colors after the rain light is more easily to be split into different colors after the rain  sound is more easily to be merger into different collision after the wind & a rainbow is formed by refraction of light by splitting light into all different colors -> a rainbow is more easily to be formed after the rain through light refraction a rainbow is more easily to be formed after the rain through light refraction  a smile is more easily to be formed after the wind through sound vegetables & sunlight is a kind of light -> sunlight and rain can cause a rainbow