Plato's Cave: Evidence of the Unreal World

The world around you is not the real world

Consider a featureless portion of this page, perhaps in the margin or between the lines of text. It is, to our perception, a smooth and featureless sheet, while under the microscope it appears as a tangled clump of matted fibres, with trace amounts of various and sundry materials such as particles of cigarette smoke, pollen, finger grease, dust, etc. trapped between the fibres of pulp. The fibres themselves are far more complex than even this microscopic view shows, and at greater magnification the cell structure begins to appear, revealing a still greater level of complexity, including desiccated masses of complex proteins and large molecules. Even a pure substance, perhaps a tiny grain of salt trapped in the fibres, reveals at great magnification seried ranks of atoms in a crystal lattice, stretching seemingly to infinity, so great is their number in even the tiniest grain of salt. The atoms in the lattice are not static, but in constant motion which can simplistically be described as a random Brownian motion, but in fact must exhibit rich and complex undulations and oscillations in response to passing electromagnetic and acoustical waves.

Like a roving eye our imagination can zoom in and grasp tiny pieces of this cacophony of pattern and motion, only as long as they are expressible in the familiar images of our everyday world. Other aspects of the scene, such as the wave / particle duality of the atoms, and other quantum effects are beyond our capacity even to visualize, being too remote from our everyday experience. Even within the familiar stick-and-ball models of the sub-microscopic world, we are completely incapable of grasping the full complexity of activity within the tiny patch of paper due to the sheer bulk of information present. And yet, all around us, every tiniest patch of our world possesses this same level of unimaginable complexity at every scale. Even at our familiar scale, although we perceive of necessity those forms and motions that are essential to survival, there remain curious gaps in our perception, for example those which are exploited by professional magicians who create the illusion of mysterious appearances and disappearances, and by movies and television that trick our eye to perceive smooth motion where there is only a succession of static frames. There is also the world of visual illusions, where straight lines can appear bent, solid percepts pop out of flat figures, and patches of color appear different than they actually are. These phenomena clearly indicate that our perceptual world is not the same as the objective world. Besides the visible world, science tells us that our world is bombarded by radiation of every sort. If we could but see in radio waves, infra-red, ultra-violet, and x-rays, we would see superimposed on the world around us a number of eerie unfamiliar worlds, in some of which the earth and sky glow like the inside of a furnace, while in others the sky is black, and the earth as shiny as a steel plate. All of these worlds are real, and exist simultaneously around us, but remain both invisible to our senses, and far beyond our abil ity to grasp even if we had the appropriate sensors with which to detect them, for we would also need additional qualia to represent those unfamiliar wavelengths in our perceptual world.

It is this invisible unknowable world that represents the objective external reality studied by science. Although we can never grasp the full complexity of this external world, we can, at least, by comparison appreciate the relative simplicity of the perceptual world that we do see around us. Our sensory world is therefore indeed an impoverished representation, but it is not impoverished with respect to the solid world we perceive around us, but rather that solid world is itself an impoverished representation of the real physical world which is beyond our capacity to detect or comprehend. For even the most complex and dynamic percepts, ocean waves crashing on a beach, the sparkling water of a babbling brook, a forest swaying in a gale, all of these images are immeasurably impoverished relative to the physical phenomena of which they are a mere shadow, and yet every glint and sparkle, every shudder and sway that we do perceive, we perceive only by virtue of the fact that our perceptual system has tracked and characterized that objective motion, and duplicated it in the internal representation that we observe.

It might still be argued however that although our senses perceive only a tiny subset of the features that exist in the objective world, that nevertheless those features are perceived exactly where they lie within the objective world. For example although we cannot see the atoms in this paper, we can think of those atoms as being located within the smooth sheet that we do perceive, so that the world we perceive would be considered as a subset of the objective world, and superimposed upon it. This cannot be the case in fact, because the perceptual world including the featureless sheet is located inside our head, whereas the atoms to which it corresponds are located external to our heads. Furthermore, the perceptual world must be represented in miniature in order for the perceptual copy of our head and body and the room around us to all fit within the confines of our true physical head. Finally, the coordinates of the perceptual world are not at all aligned with those of the objective world, but rather they define a separate and disconnected reality, like an architect's model standing in the lobby of the building of which it is a miniature copy.

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