Roger:

Though very abstract and not particularly good in visual/exhibition terms,
the most far-reaching event of the 20th century must surely have been the
virtually single-handed development by mathematician Alan Turing in the
early 1940s (originally within the phenomenonally successful British WW2
code-breaking operation) of the algorithmic basis of computing and
artificial intelligence.

Arguably, despite almost 60 years of quite astonishing development and
explosive growth in power etc., computer technology has still not
quite caught up with the explicit framework laid down by Turing.

Also, unlike the other British genius of his generation, Frank Whittle,
inventor of the jet aero engine - who lived to see millions of successive
generations of his invention in use and world recognition through its
half-century and beyond, Turning was hounded into suicide at a time in the
early '50s, when "Big Blue" - then still called International Business
Machines - thought that the total world market for computers would never
be more than a few dozen 100K (not a mis-typing!!) or so machines,
weighing in at about 5 tons each.

Patrick Boylan