Everybody thinks Manhattan’s avenues run north-south and the streets east-west, but it isn’t true.  The whole grid is actually titled 29 degrees to the northeast.  29 degrees!  This is why the Empire State Building looks so nice when seen from the “south” on a sunny afternoon—you’re actually viewing it from the southwest.  In fact Broadway, which we think of as running diagonally, is the road that approximates north-south; and even Broadway actually tilts slightly to the east.

It fascinates me how few people are aware of this situation.  Most NYU mathematics professors don’t know about it (I’ve asked them), nor does the man on the street (just one of the three I sampled).  Maps depict avenues vertically, often without an arrow to indicate north.  The NYU maps posted all around Greenwich Village compound the deception with an outright lie, including an arrow for North that points straight up.

Does it matter?  What is truth?  My feeling is that we get through life with all kinds of useful approximations, and until better data comes along, I’m going to take the view that their alignment with the truth, on average, is around 29 degrees.

[21 September 2013]