importantly from a very fundamental perspective which is the physics that tells us light occupies a very special region of the EM spectrum this is the only part of the EM spectrum that allows us to probe molecules directly so we have access to the molecular information we know the importance of molecules in biomedicine right so we have to use a light and because light can probe molecules we can apply this to biomolecules all the biomolecules you can think of right you can read the four major classes of biomolecules some other endogenous or