| Conference
Observation of the Winter Solstice

Each year, around the winter solstice, the Cathedral of Mallorca offers us the spectacle of a giant kaleidoscope of color. Light rays enter in a perfect way through the major rosette, the one of the altar, and out of the main door rosette, the western one, so that a colored cylinder is created. Viewed from the terraces of Sant Pere Baluard, it is one of the most beautiful sunrises that can be seen.

This geometric and scientific phenomenon has been studied by the Balearic Mathematics Society (SBM-Xeix). After observation of this effect in Aljub Es Baluard a conference Iluminando y vigilando el Baluard de Sant Pere  (Lighting up and watching over the Bastion of Saint Peter) imparted by Clara Grima, of the University of Seville.