Bloom is not being hyperbolic in Calypso when he
muses, "Good puzzle would be cross Dublin without passing a
pub." Indeed, many intrepid walkers and drinkers equipped with
maps have been defeated by Bloom's puzzle in the nearly 100
years since the publication of Ulysses. In 2011,
however, a software developer named Rory McCann used a
computer algorithm to thread the maze.
McCann, a UCD computer science graduate, did it by defining
borders along the Royal Canal and the Grand Canal (the
commonly recognized boundaries of Dublin in Joyce's time),
plotting the locations of over a thousand pubs within those
borders on a street map, establishing an exclusion zone from
the front of every pub defined by a parameter of 35 meters,
staking out 15 points along the northern boundary and 15 along
the southern one, and writing a program whose task was to find
a route from some point on the northern border to some point
on the southern one, traveling along city streets and avoiding
the exclusion zones.
As soon as McCann published a result, members of his online
community wrote to inform him of pubs that he had not included
on his map. Hah! After several iterations, the computer found
a single route from the northwest to the southeast that McCann
feels reasonably confident about. Interestingly, although the
plotted route avoids every pub on McCann's map, it did manage
to pass directly by the Guinness brewery at St. James' Gate.
Hah!
Reporting on the feat in 2011, the Daily Mail observed,
"Particularly likely to come under attack from pedantic Joyce
fans is his decision to ignore hotels and restaurants which
serve drinks and may even have their own bar inside." McCann
acknowledged in that article that "It's a contentious issue. .
. . But they are not pubs." Hah! The reporter concluded the
article by noting, "Others have long since claimed the answer
to the riddle was simple: you can cross Dublin not passing any
pub by simply going into them." Hah hah!
