Sir, What an amazing piece by Brendan McWilliams (May 23rd) on the physical conditions required to produce a rainbow and what an amazing metaphysical reality, stunning, at once, in its simplicity, and in its implications for an understanding of the universe, lay hidden and unacknowledged beneath the mathematical equations.
In his abide BMcW listed two essential prerequisites for a rainbow, sunlight and raindrops, and the positions that they must take relative to each other before this very real phenomenon can exist. One must take it for granted that the observer, whose position relative to the other two must also be mathematically precise, is a third prerequisite. Implicit in this description of the physical conditions, and of the mathematics behind the occurrence of a rainbow, is the premise that, in the absence of any one of the three prerequisites, a rainbow simply cannot exist.
It is self evident that there can be no rainbow in complete darkness. Equally there can be no rainbow in totally dry conditions. It may strain the imagination, but I don't think that it strains logic to deduce from the foregoing that a rainbow, therefore, cannot exist in the absence of an observer. Not only must the observer be present, but the very position of this observer, relative to the light and water droplets, is crucial.
By another small leap of the imagination it could be postulated that the rainbow is a metaphor for all physical reality and that nothing, in fact, exists without an observer. Put another way, nothing exists unless it is perceived to exist, and, since it is through our perception that we are aware of our physical surroundings, it is equally logical, in my view, to say that the universe, is as we know it, exists solely be cause we perceive that it does. Like the rainbow, we are essential to its creation and it simply can not exist without us. In a very real sense we create for ourselves the whole world, the entire universe, the laws that drive it, and, indeed, ourselves in it The fact that we, with our individual awareness, are generally in broad agreement about the physical traits of our world suggests that either great minds think alike, or that, in a very real sense, we're all of one mind.
Following the logic of the foregoing, it could be said that, since all the theories put forward to explain the universe, from July to Quantum Theory, are, quite simply, constructs of our own imaginations, the physical traits of the universe change to fit our altered perceptions of it. We change the universe by the very act of observing it and developing theories to explain it.
The Anthropic Principle, well known to physicists, suggests that we perceive the universe to exist as it is, because were it to be any different, we would not have evolved to be here to perceive it! I would like to postulate the following "anti anthropic" principle, viz, for the universe to exist it is essential that there must be an intelligence capable of bringing it into being.
In a world which has become more credibly explained by science than by religion, we have lost sight of the spiritual reality that underpins our existence. It is my view that physics and metaphysics cannot exist in isolation. To separate them is to ask which comes first, the scientific chicken, or the spiritual egg. Physics or Mind. Yours, etc. Corbawn Wood, Shankill, Co Dublin.