The question of whether something can exist, without being recognized by a sentient being is an age old one. Most of us are familiar with the philosophical conundrum as to whether a tree falling in a lonely forest has actually made a sound. The rainbow represents a particularly interesting example of something which seems to both exist and yet not exist simultaneously. The rainbow, by definition, is an image which occurs only when refracted light lands on a retina (or other light receptor) and creates a coloured arc image in the conscious perception of an observing being. Since the image on the retina occurs only because the retina is present to receive it, it is logically valid to assert that a rainbow’s very existence necessarily requires refracted light AND a receiving sensor of a conscious being in order to genuinely exist. Something that is equally special is the fact that each being “in receipt” of the image is observing something which is wholly unique to that particular being, since only one being can receive the exact light rays applicable to their image. Other beings, whilst seemingly seeing the same rainbow, are actually seeing different rays of light (as light rays travel in straight lines and beings see only those light rays which are directly in line with their own light receptors, in their own retinas). Therefore, despite the apparent beauty of the rainbow, they also possess an intellectual and philosophical quality worthy of our deepest consideration and wonder.