Does God have shares in Sony?
he headline is facetious (obviously) but serves to lead us into a serious scientific observation. As most people realize, human vision and hearing is less than perfect, but have evolved to get the maximum usefulness - for example, hearing has maximum sensitivity at the frequency at which babies cry: an obvious survival trait.
But there are three flaws in hearing and vision which appear to have no evolutionary value, but without which the entire entertainment industry would not exist.
1. Persistence of vision: the ancient Greeks knew that the eye retains images for a split second, but it will also see a succession of slightly changing pictures faster than about 6 per second as a moving image - a fact exploited in toys such as the Zoetrope from the 1829 on. Without this flaw, the whole cinema and television industry could not exist.
2. Recreation of the fundamental. Musical notes are made up of the actual basic pitch - the fundamental - and a succession of lower-level frequencies increasing in a mathematical progression (harmonics), the relative level of which give the note its tone quality. If you filter off the fundamental (as small radios do for the lower notes) you would expect to hear the pitch of the lowest available harmonic - but in fact the ear recreates the fundamental and hears the correct pitch, albeit not very strongly. Of course this effect can never arise in nature. Again, a flaw in perception without any survival value but without which only really big loudspeakers would be any use.
3. Phantom audio images. It's an obvious survival trait that we can locate the direction of a sound: but if we hear two spaced identical phase-coherent sounds (a situation which again cannot arise in nature) we perceive them as a single sound located between the two: this flaw has been present from the dawn of human history but no-one heard it until experiments in Paris in 1881 using dual telephone lines. Without it there would be no stereophonic sound.
So these three flaws in our perception have developed in the course of evolution over millions of years, but have no survival value and only became of use in the last 200 or so years: and without them there would be no entertainment industry. Hence my facetious headline question: does God have shares in Sony?
Posted: Fri - November 17, 2006 at 08:38 AM by Roger Wilmut
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Published On: Mar 11, 2016 05:00 PM