From DAISY FELIX
The anomalous behaviour of the digital clock on Godalming Station (Letters,
3 and 24 July) provides an interesting challenge in deductive logic. Leaving
spurious metaphysics aside, my companions and I permitted ourselves the
duration of the journey from Malet Street to Egham to determine the simplest
mechanistic explanation for the appearance of an ‘eight’ instead of a ‘zero’.
For example, could it be the result of a simple short-circuit between any
two of the seven segments of the display? It appears not.
This substitution requires the unique condition that the centre horizontal
segment be activated when it, alone, should not. Since all the other numbers
display correctly, a truth table quickly demonstrated that there is no other
segment to which a direct, interconnection could be made. A similar analysis
shows that there are just three one-way, diode-like links which could account
for the observation. Can any logician tell us please, what is the simplest
mechanistic explanation?
Daisy Felix Academic Commuters’ Study Group London
