How do photons carry information? For instance, when a photon is emitted by the sun, it seems to carry information about the sun- color, intensity, etc... If that photon bounces off a blade of grass then it carries new information- color, shape, etc... What is it it about the blade of grass that allows its information to "stick" to and be carried by the photon? Is any energy lost by the blade of grass in the transmission of information from itself to the photon? Also, if a photon is emitted by the sun, does it expand like ripples in a pond, or is it like a point-particle emitted in a certain direction? Or if a single elementary particle in empty space emitted a photon, would it be seen in every direction from the point of emission? Thanks.