Aachener DOM (=Cathedral of Aix la Chapelle) The Cathedral is my favorite church of all churches I have ever seen. And I have seen churches from Helsinki to Cordoba, from London to Istanbul. It is something very special: in European history in Architecture and even in Mathematics.

The Cathedral of Aachen is one of the oldest cathedrals in Europe. It was constructed by order of the emperor Charlemagne (=Karl der Große) in the year 800. He was crownd and buried there. You can see his throne and his coffin . For 600 years in this cathedral 31 kings and 12 queens were crownd.

Charlemagne was not only the king of Germany but the emperor of a big part of Europe.

He was travelling around his empire all the time and was sleeping in different palaces called „Pfalz“. You can visit his house in Aachen. It is now the town hall. In this house every year the international Charlemagne Prize is awarded to great Europeans. Go inside, it is great!

But now I come to the main aspect: The Cathedral of Aachen Most of the marble you will see had been transported to Aachen from Italy in the 8th century!

From outside: Important and more than 1200 years old is the red heart of the cathedral with the cupola. It is an octagon (8 angles) in a hexadecagon (16 angles). All other chapels have been built in later periods.

This is the ground plan of the cathedral, black is the main old part This is the ground plan of the cathedral, black is the main old part. You can see the octagon and the hexadecagon. The throne and coffin are in the middle left and right

Surprise!!! Surprise!!! Surprise!!!

You know Stonehenge in the South of England?

Here you can see the ground plan of the cathedral (white) and the ground plan of Stonehenge (black). Stonehenge is a big sundial (clock) to measure the equinoxes (when day and night have the same length) and midsummer and midwinter (longest day and night).

What does that mean to the cathedral of Aachen What does that mean to the cathedral of Aachen? You must know Stonehenge and Aachen lay nearly on the same latitude. And the cathedral is nearly the same sundial as Stonehenge.

The sunbeams are different during the year The sunbeams are different during the year. From the highest point in summer to the lower point on Easter. You can see on the right side. In the morning during the mass at the church the sun was shining through different windows and illuminated the head of the emperor. They had no electric headlights. But this is a good illustration for the word headlight :-) But it only works when the sun is shining.

You can find more geometrical mysteries in the cathedral You can find more geometrical mysteries in the cathedral. Look carefully and tell us what you have seen. Page 6

Do you see the grid with geometric pattern? Believe it or not: The shadow of the grid on the floor is rectangled and squared only when day and night have the same length.

Every where you go: mathematic mysteries are waiting for you. Open your eyes! Discover the Unknown! Thank you for listening to this hexadeca-presentation!