"The city of Königsberg in Prussia (now Kaliningrad, Russia) was set on both sides of the Pregel River, and included two large islands which were connected to each other and the mainland by seven bridges.

The problem was to find a walk through the city that would cross e...ach bridge once and only once. The islands could not be reached by any route other than the bridges, and every bridge must have been crossed completely every time; one could not walk halfway onto the bridge and then turn around and later cross the other half from the other side.

Of course one could try to track all the possible paths and try (trial and error) but it would be a very tedious work.

A mathematician who lived at the time, Leonard Euler, chose a different approach." (Wikipedia)

This approach developed into a new branch of mathematics known today as Graph theory.

Graph theory has applications in different fields : electric circuits, ecological systems, social studies, urban planning, networking,... simply: anywhere a "relation" between two "nodes" is involved.

The presentation doesn't require any prerequisites, it is prepared for general audience.
The slides are in English but the presentation and discussion are held in Arabic language.

The invitation is @ 7:30 pm. We'll start @ 8:00 and we'll actually prove that, if within a group of people, every two have a common friend, then there exists a person who is known by everyone in this group, called the politician!!!

For more info:
suzy_maddah@hotmail.com
03-063989