Madrid and Melbourne surround the world, and streams of data bathe it. If you were to push a pin through each of them on a desktop globe, it would turn with the merest of wobbles. I am lucky enough to have a base in each of these two cities, so my current joke is that “I have the world surrounded”. Bloody hah, I know, but hence the name.
It is also the case that Madrid and Melbourne are at the extremes of the spectrum of livable cities. There are bigger and denser cities, and also smaller and sparser ones. But Mexico City - Minneapolis or Moscow-Milwakee do not roll of the tongue as well, and, above all, do not surround the planet (although Mexico City is on a race with Tokyo to do it on its own).
So Madrid and Melbourne are here as a synechdoche for the two endpoints in my favourite segment of city livability. They define a line along which we can study all cities, reading into urban life through the datastreams each city produces. Think of madrid-melbourne.org as “information aesthetics meets City of Sound“. Or something.