Ten years ago, a number of streets in Faro were completely renovated. One million euros were available - and the money was not only used in a pragmatic and practical way, but the Portuguese tradition of the calçada portuguesa (Portuguese sidewalk) was also maintained.The characteristic Portuguese paving (mostly made of white limestone and black basalt) was supplemented with a special kind of eye-catcher: on the Passeio da Rainha, the number Pi (or as the mathematicians say: π) is not carved in stone, but is nicely paved as a sidewalk with the 3 in front and the first 79 digits after the decimal point. We could have gone on indefinitely (who doesn't like to remember math lessons!? Or at least the Wikipedia article...), but unlike π, the Passeio da Rainha is real and finite.
Why did such an old mathematical thing (Archimedes was already working on the ratio of the circumference of a circle to its diameter in 250 BC and came to an acceptable result - to two decimal places, after all) find its way into the pavement? Is it because Faro's mayor Rogério Bacalhau has a degree in mathematics and has taught mathematics to several generations of pupils and taught mathematics at the University of the Algarve (between 1990 and 2000)? (Source) In a report on the construction measures, colleagues from the southern Portuguese information portal Sul Informação naturally also speculated about connections between the professor's job as mayor and the sidewalk design - but he waved it off: "I like the fact that it's a mathematical symbol, but it was a joint decision in the city council," Bacalhau told Sul Informação.
