If the speed of light in vaccum and air is same then how can we say that the star light coming from space to the atmosphere of earth is refracted, because only if vaccum is optically rarer than atmoshphere of earth the star light would be refracted so does it actuaaly mean that speed of light in vaccum is more than speed of light in atmoshpere of earth???
While traveling their course they get refracted by gases in space. Furthermore speed of light is same in air if and only if air is free from dust and ice crystal. Due to clouf light gets refracted before reaching our eye