distribution…and in almost all systems (IBM, actors, power grid), the tail of the distribution follows a power law.”
Reading this simple statement in an email during a break between sessions, Barabási was stunned. Back in the conference hall, he recalls in Linked, “I found myself…paying no attention to the talks, thinking about the implications of this finding. If two networks as different as the Web and the Hollywood acting community both display power-law degree distribution, then some universal law or mechanism must be responsible. If such a law existed, it could potentially be applied to all networks….During a break between talks I decided to withdraw to the quiet of the seminary where we were being housed. I did not get far, however. During the fifteen-minute walk back to my room a potential explanation occurred to me, one so simple and straightforward that I doubted it could be right. I immediately returned to the university to fax Réka, asking her to verify the idea…A few hours later she e-mailed me the answer. To my great astonishment, the idea worked. A simple, rich-get-richer phenomenon, potentially present in most networks, could explain the power laws we spotted on the web and in Hollywood.” (p. 80)
On the flight back from Portugal, Barabási began to write up a description of the simple, elegant model. Nodes with more links get more links. That, and a growing rather than a static network, was all that was necessary to generate hubs and power law scaling. The long flight, he recounts, “seemed like an ideal opportunity to prepare the first draft” of a paper. But things were not to go so smoothly. “A soon as the plane took off, I pulled out a laptop newly purchased before the Porto trip and frantically started typing. I was just about finished with the introduction when the flight attendant, handing a Coke to the passenger next to me, suddenly poured the entire
contents of the glass onto my keyboard. Random letters flickered on the screen of my now useless laptop. But I did finish the paper on the plane, writing it out from beginning to end in longhand. A week later it was submitted to the prestigious journal Science only to be rejected after ten days…because the editors believed the paper did not meet the journal’s standards of novelty and wide interest. By then I was in Transylvania, visiting my family and friends in the heart of the Carpathian mountains. Disappointed but convinced that the paper was important, I did something I had never done before: I called the editor who rejected the paper in a desperate attempt to change his mind. To my great surprise, I succeeded.” (pp. 80-81)
After the publication of the Science paper (Science 286:509-512, 1999), Barabási took what was, for an untenured assistant professor, a great leap of faith. Despite the advice of friends and colleagues who told him it was a risk, he decided to switch his whole group from materials science to the study of networks. Some people left the lab; others, as intrigued by networks as Barabási, Albert and Jeong, stayed. For a brief period, the advisability of the switch seemed in doubt, and Barabási recalls that his grants were not funded for two years. But as more major papers appeared from his group in journals like Science and Nature, it quickly became clear that his instinct had been right. Papers followed in rapid succession, exploring network dynamics in a variety of systems. Barabási’s group explored various aspects of network dynamics, adding more realistic parameters such as fitness, and exploring the relative vulnerabilities of hub-like and distributed networks to failure and to attack. On the more practical side, Barabási got his tenure; six months after that he was promoted to a name chair position.