h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I thought that was the Turkish spelling. "Sophia" is the Greek.

You are correct of course. Hagia Sophia was the original Greek name (The Holy Wisdom. The church/mosque is indeed a beautiful building, although in a somewhat shabby state at present, the Turkish government not taking such good care of it as they could. (When I was last there the great dome was filled with scaffolding.) The wonder of this building lies not just in it's beauty, but in its architectural significance. The architects (whose names I forget) were faced with a problem. Greek churches tended to be square, and the Emperor required a huge circular dome. The problem weas how to mount a circle (the dome) on a square. They solved this beautifully by inventing pendentives, fillers that turn the square base circular. These are obvious from inside the church. This method has been used ever since! It si aslo amazing to think that the church is so old, nearly 1500 years, and try to drink in the atmosphere when you are there. This was the greatest church in the greatest city in the world!