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Analysis Following Buridan, an ass
was at an equal distance from two piles of hay, and dies of hunger. It was only recently that I came across “The Glitch”
within a computer, where it is accepted that the two choices cannot be
exactly equal. The new insight was that the closer the ass was to the
mid-point, the longer it would take for it to decide which pile of hay to go
for. That is the apparently frequent dilemma faced by a driver when the
lights change “at the last moment”. It is unknown to driving instructors and
driving examiners. The problem was known in ancient times, but only the
impossible case of equidistance. Increased delay when very close to equidistance,
so that the ass can take too long to decide which pile of hay is nearer, when
one really is nearer, and so dies anyway, was only thought out when digital
computers came. However, the existence of the problem was suppressed for
decades, and is probably still not taught in any relevant college computer courses. Ivor Catt. 18 August 2011 |
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http://en.wikipedia.org/wiki/Buridan's_ass A common variant substitutes two identical piles of
hay for both hay and water and advances that the ass, unable to choose
between the two, dies of hunger alone. http://wordsmith.org/words/buridans_ass.html No mention until me that the closer the
ass is to the middle, the longer the ass will take to make the decision. That
is the situation I found in a computer. A computer must accept a data
transfer beginning in this clock cycle or the next, and cannot decide whether
the request came in time or too late. The result is a half sized signal which
is neither a false (0v) or true (5 volts), which propagates throughout the
machine which does not understand a half truth, being digital. The computer
crashes. I suspect that "The Glitch" is unknown
to driving instructors. A driver sets out a certain point - perhaps 15 metres
- before the lights. He will stop if the lights change before he reaches that
point. The closer he is to that point, the longer it takes him to decide
whether to stop. Very occasionally, he cannot decide in time. The lights cycle through RGYR once every 100
seconds. The driver cannot decide in time if he is .001 metres from the
decision point when the lights change. That is, once every 100,000 times, he
cannot decide in time, and ends up half way across the crossroads, stopped. A driver comes to (and passes) traffic lights
100 times per day, 30,000 times per year. According to these figures, he ends
up stationary half way across the crossroads once every three years. If these
calculations are correct, we have to jail a lot of dangerous drivers. Ivor |