We all know that light follows Rectilinear Propagation and it sometimes bend while diffraction, but i never understand the concept of rainbow and the reason why it is a curve. I have read books and all and everywhere it says that white light passes through raindrops and boom! It is now a circular arc of 7 lights. I understand the phenomenon of refraction and know light of different wavelengths separate when passes through a prism. But after passing through prism, those light travels straight.
But why is rainbow curve? 🌈