I recently watched a program on TV called How Kevin Bacon Cured Cancer. It was a really interesting documentary that followed some scientists and mathematicians as they tried to discover the mathematical theory and structure that supports networks. Kevin Bacon was of course the person who was the example used in the popular theory known as Six Degrees of Separation.
These networks apply to brain functions, cells, computer systems, viruses, the spread of disease, air traffic flight paths, and social networks like Facebook and Twitter, and many other systems or networks.
The concept of “hubs” enabled them to provide a richer and more comprehensive structure to the mathematical theory. Kevin Bacon would be the original celebrity “hub”. Heathrow Airport is a major hub in the air traffic systems. What makes a “hub” I wonder? When you think about people in social networks it can be due to popularity. In Facebook the number of “friends” you have is an indicator of this. But how many are manufactured and how many are genuine? Barrack Obama on Twitter would be a major hub in that system and a genuine one at that.
At the other extreme of this is what I have called “the lone cowboy”: the loner; the person who doesn’t want or need lots of people to validate your own identity in this world. It is someone who wants to opt-out of society and doesn’t want to be a part of the social network. This link in the network might be like a little regional airport, the less-used brain cells, or the person who lives a solitary existence.
I hope the mathematical theory does not conclude that the points with a small number of links are not any less needed or significant than the popular hubs in the network. My own tendencies move toward the less busy parts of the network.