World is a small place - Know about the '6 degrees of separation'

Billions of years ago, life on Earth started in a primordial soup. With the single celled organism, life eventually sprang up in water. Later, it evolved into creatures living on land, until we, the most intelligent (though I believe as most complex) found our mojo & began to rule the planet (& hence destroy it). Well this blog doesn’t speak about our wrong doings on the Mother Earth but is on an interesting thought put forward by one of our own kind.

Since the origin of Life can be traced to a single organism, it is pretty much self-evident that all of us are somehow related to one another. But how close are we actually? In the sense, if you have to reach to another unknown person somewhere at the opposite side of planet, will you be able to reach out to her/him? If yes, how many threads have to be cut to reach the person holding the fleece? 

Continue reading to know more..

Six degrees of separation

The Idea- Six degrees of separation

There have been many ideas/suggestions put forward by scientists throughout the history. One such has been 'Six degrees of separation'. Before elaborating on the idea, let me put the thought succinctly.
'Six degrees of separation' means that one can connect to any unknown person in the world through not more than 5 steps.

5 steps. What does this mean? As said, let me try to delve on the idea put briefly above.
Supposedly, you need to connect to Rahul Dravid (I really want to, he being my hero), What I say that you may be able to reach out to him via not more than 5 connections? You approach someone known who you think has the best chance to know him. She/He in turn may further reach out to the third person who shall be a good bet to reach our destination. Likewise, the chain continues until you finally hit 'The Wall' i.e. the Man himself. As what the idea suggests, this chain shall not be more than 5 people long (generally).

Dravid here is a famous personality. But what if the case is of an unknown guy, say a taxi driver in Riyadh? As per the concept, any unknown person present in any part of the continent can be reached out to via 5 intermediary connections. But then, is there any scientific backing to the claim? There is one mathematical justification to it.

Let's say a person is connected to 45 people, who in turn are connected to 45 another set of different guys, and each of these further know 45 unique humans and the chain continues until 5 such levels. Calculating the number, we have 45^6=8E9 or 8 billion people. Which is more than the current world population (7.7 billion). You may argue that population is bound to increase so this equation may fall apart. But as population grows, so does the technology bringing more people closer to one another. So this equation may take 46 as the base in near future.

The above is a just a numeric explanation. But how did it all start and was any experiment conducted to check it?

Experiments/Researches done on the theory

The idea was first proposed by the Hungarian writer Frigyes Karinthy in a short story called Chains in the year 1929. Later, in the year 1967, an experiment was conducted by American sociologist Stanley Milgram which he called "the small-world problem." He asked a selected group of people to send a package to an unknown person but whose name, profession and city was known. The group was asked to send the package to their acquaintance who was the best bet to know the target. The next person was also asked to forward the package and the chain would continue until the consignment reached the destination. Surprisingly, of all whose packages reached, the average path length was 5.2 intermediary connections. However, the research was struck down owing to small sample size and low success rate. But the idea stuck and a few other scientific/generic experiments followed.

Microsoft conducted a research in the year 2008, when using its instant-messaging network 'Microsoft Messenger' it studied 180 billion different pairs of users in the database. They found out that 78% of the users could be connected in less than 7 hops. The average length was 6.6 hops and the researchers said that there are about 'seven degrees of separation' among people.

The phrase 'six degrees of separation' may or may not be true in exact sense, but the countless technology platforms have definitely reduced the separation between all of us. And this is further diminishing at a quick pace. As is rightly said, 'World is a small place' - if you believe it to be !

Nerd notes:

1. Remember Dijkstra's algorithm from Engineering? His algorithm has been used by researchers at FB & others to find the shortest length between 2 nodes (i.e. 2 people)
2. In 2016, the popular social network Facebook found it in its research that the average separation among its members was 3.5 degrees.

Thanks for reading. Keep smiling !

Prakhar