Revised: Summary and Personal Reaction to "Six Degrees of Separation" (Barabasi p 25-35)

Summary
Six degrees of separation is a theory that any two people on Earth are connected to each other through a chain of acquaintances with no more than five intermediaries. The hypothesis was first proposed in1929 by a Hungarian writer Karinthy Frigyes in a short story called “Chains”, and was first confirmed in 1967 by a Harvard professor Stanley Milgram. Milgram performed experiment by sending letters to randomly chosen people to find out the distance between any two people in US. The result was that the median number of intermediate person is 5.5. To find out how many links are between webs, Barabasi’s group conducted experiment to obtain the data that any two documents is on average nineteen clicks away from each other. Barabasi emphasized that small separations are common in almost every network, by giving the examples that species in food web are separated by 2 links; molecules in the cell are separated on average by 3 chemical reactions; scientists in different fields of science are separated by 4 - 6 co-authorship links; neurons in the brain are separated by 14 synapses. Barabasi also used mathematical formula to verify the small separation in networks.

Reaction
It is surprising to know that the medium between any two persons is only six people. This is a very important idea or theory. The positive side of the "small world" is that “every person is a new door opening up into other worlds”. The negative side of it is that confidential information could easily be spread and misused. Making friends as many as possible is broadening a person’s view and possibility. However, we should also be aware to protect ourselves from damage of losing privacy in the modern network times.

My issue in the Theme Writing class is about HIV. AIDS is one of the most serious health and social problems in the world today. The latest statistics on the world epidemic of AIDS and HIV shows that 38.6 million people are living with HIV, 4.1 million became newly infected with HIV and 2.8 million people died of AIDS in 2005. I think that the theory of “six degrees of separation” can partly explain the rapid spread of the infection. Moreover this theory reminds people that the spread of epidemics is much faster than we think.

Also we are trying to send our sticky message now. Based on the theory, if I send message to 10 people and assume that they send it to 10 other people, repeating this for 6 times, we get 10^7 (10 million) people. Therefore I got confident in the IE project. My sticky message is to protect the environment, which is very important for everybody. So I think it can be understood and accepted by many people and be spread widely.