[Tutor] Re: [Tutor] Re: Sorting a dictionary in one line? [p rogramming is hard / Dijkstra's remarks]

alan.gauld@bt.com alan.gauld@bt.com
Wed Jan 22 06:05:01 2003


It's a good enough paper but one point of his discourse is flawed:

> In computer programming our basic building block has
> an associated time grain of less than a microsecond, but our 
> program may take hours of computation time.  I do not know of 
> any other technology covering a ratio of 10^{10} or more: 

In fact most technologies can show instances of the same order. 
For example in Civil engineering bridges and the like may stand 
for thousands of years but in the event of failure a hairline 
fracture can rupture in milliseconds.

In Electronics the basic unit of tiume is nanoseconds (and 
increasingly pico seconds) but may electronic systems run 
for long periods - manufacturing production runs etc, even 
timers operate over periods of hours or more. 

Astronomers have even longer timeframe differences, but 
arguably are not a technmology per se.

Computer Scientists seem to have a strange built in belief 
system whereby, somehow, their problems are significantly different 
to those in other engineering disciplines. They are not. 
The only real difference is that CS lacks a complete 
theoretical basis (pysics etc) with which to perform analyses.
But this was true of most traditional engineering disciplines 
too for many years - think medieval buildings...

Alan g.
Author of the Learn to Program website
http://www.freenetpages.co.uk/hp/alan.gauld/