Hello Emperor Haile Selassie, I'm pleased to meet you (kind of)!

Ever since I first came across the idea of small-world networks, I've been fascinated by them and how they relate to our everyday life. If you've heard of small world networks, it's almost certainly in the context of the "six degrees of separation" hypothesis, the  the idea that everyone is on average approximately six connections away from any other person on the planet. There's an excellent wikipedia article about it if you want to learn more.



Six degrees of separation

  It seems implausible and perhaps counter to common sense but, on testing through various social networks, researchers have found that, so long as reference is to the average number of connections, something between 5 and 7 is quite normal (the average separation for all users of Facebook, for example, is 5.73 degrees, with a maximum chain length of 12). 

Another example that was popular (in a geeky kind of way anyway) back when t'internet was young, was what Nature magazine quaintly described as a "collaboration graph of film actors", but which the rest of the world heard of as the "Six Degrees of Kevin Bacon" game, in which (presumably movie-savvy) players try to connect any individual actor to Kevin Bacon as quickly as possible and in as few links as possible. Again, it is well-described elsewhere.

Small world network ideas have been adopted quite widely as a means of describing and exploring systems in physics, neurobiology, geology and for technological networks. But it is connections between people through social networks and billions of individual relationships that I find most interesting. Even exploring Facebook friends' lists of their friends can identify some surprisingly short chains of connections. Through two friends lists, I was able to identify with only two or at most three degrees of separation almost all of the most well-known BBC News presenters and foreign correspondents. Now, through them, presumably is a 3 or 4 degree chain to most of our leading politicians and many of those in other countries. Fascinating stuff!

I thought I'd try a wee experiment for which an opportunity presented itself recently. One of my dog-walking friends makes frequent extended business trips to various parts of Africa and was to make his first visit to Ethiopia. I challenged him to find and shake hands with someone who had shaken hands with the Emperor Haile Selassie, "Ethiopia's regent from 1916 to 1930 and Emperor of Ethiopia from 1930 to 1974. The heir to a dynasty that traced its origins to the 13th century, and from there by tradition back to King Solomon and Queen Makeda, Empress of Axum, known in the Abrahamic tradition as the Queen of Sheba". This was quite a challenge as Selassie died in 1975 and so, presumably, the number of surviving people who have met him shrinks, if not daily, then at least annually. In fact, it would be an interesting exercise to try in Britain, where Haile Selassie was in exile (in Bath) between 1936 and 1941, while Ethiopia was occupied by Italian forces. He also made at least one state visit (in 1954) and apparently travelled widely, meeting many British citizens. There was an interesting run of articles on the late John Peel's much-missed Saturday morning Radio4 show, "Home Truths", where people recounted their tales of encountering the Emperor!

I met my friend this morning, recently returned from Ethiopia. He shook my hand, having tracked down and shaken the hand of an Ethiopian man in his 70s who was the warden/custodian of an Imperial palace built by an earlier (presumably then Abyssinian) Emperor and who claimed to have shaken the hand of Emperor Haile Selassie. From me to Emperor Haile Selassie with three degrees of separation. Hello, Emperor Haile Selassie, I'm pleased to meet you (kind of)!

Emperor Haile Selassie