Network Theory

I have been meaning to write about this for some time but never quite got around to doing so - there have been a few reference to the concept of 'Six degrees' on several e-groups that I am a member of - indeed, the idea of 'Six degrees' propounded rather simplistically back in the late fifties basically was that every body in the world is connected to somebody else perhaps half way around the globe by six degrees of separation i.e in six hops it is possible for anybody to connect with anybody else in the world or in other words somebody you know, knows somebody else who knows someone else who knows yet another person and so in six such hops you can connect with a person who lives a world away and who you may never have set eyes on! Well, the idea was thought of as yet another urban legend or myth and nobody quite had tested it . Recently it turns out that it has been tested by a couple of Universities in the US and found to actually be not mere urban myth but very much true.

The testing involved getting a packet across from some of the remotest parts of the world to a particular person at Harvard University, Boston without actually having the address of the person in Boston. A couple of courier companies were recruited to fly packets addressed to that person for free, no matter from where it is coming and a notation was made as to how many hops the package made to get to Boston! Incredibly, some 27 out of 40 packets made it to Boston from far away villages in Kenya and India and Inner Mongolia in less than six hops!! In other words the network actually found the final address of the person in Boston as it went along its way!

So Six degrees is no more a myth - the concept has actually evolved into the science of Network Theory, a highly abstract, mathematical concept that has now become central to the idea of fighting stuff like terrorism and cancer!! A quick reading of the piece below will tell you how!! If you are too lazy to do that let me see if I can quickly summarise the concept for you here! A network consists of hundreds of connections, some connections have a lot more connections connecting to it than other connections - these are called hubs. Thousands of hubs and connections then form the network! The Internet works this way, as do networks of terrorists and this is the way cancer spreads in the body!! The beauty of a network is that if some connections fail, the network will continue to work, albeit a little slower! But if a hub fails, then the network begins to crawl and if a few hubs fail the network itself crashes! So does this concept tell you a few things about how to kill a viral infection in a computer network? Or how to knock out a terrorist network?

Albert-László Barabási and Network Theory

At one point or another, you’ve probably heard of “six degrees of separation,” the theory that, through social relationships, you’re only six handshakes from anyone on the face of the earth. Or, you may have heard of its pop culture

incarnation, “Six Degrees of Kevin Bacon,” a trivia game in which players attempt to link any Hollywood actor to Kevin Bacon through six films (or fewer). What you may not have heard is that an exploration of these concepts, which were

once dismissed as trivialities or urban myths, has led to a new, groundbreaking branch of science known as “network theory.” By examining the unexpected ways in which all things relate to one another – from musical crickets, to websites, to Hollywood actors scientists are honing on solutions to some of the world's most complex problems.

Network theory pioneer Albert-László Barabási, a Distinguished Professor of Physics in the College of Arts & Sciences, has emerged as one of the world’s foremost experts in the science of networks. Through such innovative undertakings as a complete mapping of the World Wide Web, Barabási has discovered that certain, basic patterns underlie all connections and relationships. In his book, Linked: The New Science of Networks, Barabási writes, “There is a path between any two neurons in our brain, between any two companies in the world, between any two chemicals in our body.

Nothing is excluded from this highly interconnected web of life.” Barabási’s work is already famous; Linked is available in eleven languages, and are among the most cited field. But his research will attain level of popular recognition this February’s U.S. release of documentary called Connected:The Power of Six Degrees (also known around the globe as “How

Kevin Bacon Cured Cancer”). The Connected documentary investigates the various mind-blowing applications of network theory in our everyday lives. In the film, Barabási and other scientists suggest that computer viruses, infectious diseases, proteins in the cell, and human social groups are all governed by the same fundamental concepts. And, through the application of these discoveries to the military, to technology, and modern medicine, Barabási has a guiding hand in research that may help us to control AIDS, break-up terrorist networks, and yes, perhaps even cure cancer.