2.1 String Theory

In 1997, ScienceWatch compiled a list of top-10 most cited physics papers. Four of them were about string theory. Two superstring revolutions were documented in detail by experts of the field. The existing account of the revolutions in the field makes it an ideal case for testing our computational and exploratory techniques.

Take 1

The initial analysis was predated CiteSpace. It was visualized in a 3D animation of a network growing over time. New publications and links emerge in the scene as they get published and cited. We can locate papers associated with each of the two revolutions, but it was hard to see how they really differ from the rest of the literature. In other words, while the 3D animation is chronologically faithful and structurally accurate, but it is not enough for us to pinpoint articles that have great impact on the system as a whole.

Take 2

CiteSpace provided a solution. The goal is to single out a small number of the most important articles from a large volume of scientific publications. The selected articles should be so important that without them the rest of the literature would be hard to stand on its feet.

The new study of string theory is detailed in the 2004 PNAS paper (Chen, 2004). The goal was to see to what extent CiteSpace can reveal the turning-point articles and pivotal points in the literature. I contacted Witten with the results and he responded with useful comments.

Take 3

We revisited the case again in 2009 (Chen et al., 2009) to verify structural and temporal properties predicted by our theory of scientific discovery. In a nutshell, our theory of scientific discovery says that the value of a new discovery is measurable in terms of the potential shock it could possibly bring to the system as a whole.

Despite the fact that we were preoccupied to reproduce the turning points found in the 2004 PNAS paper, our attention was repeatedly drawn towards Juan Maldacena's 1998 paper, which stood out strongly in these properties, i.e. betweenness centrality and citation bursts, as if it is signaling us something important. I emailed Maldacena directly for comments on the contributions of his work. Here is his reply: "It connected two different kinds of theories: 1) particle theories or gauge theories and 2) string theory. Many of the papers on string dualities (and this is one of them) connect different theories. This one connects string theory to more conventional particle theories."

Maldacena is the recipient of the 2007 Dannie Heineman Prize for Mathematical Physics "for profound developments in Mathematical Physics that have illuminated interconnections and launched major research areas in Quantum Field Theory, String Theory, and Gravity."

TIME 100 Innovator website states that "he forged a connection between the esoteric formulas of string theory and the rest of mainstream physics." and "he has been able to suggest a way to knit together two theories previously thought to be incompatible: quantum mechanics, which deals with the universe at its smallest scales; and Einstein's general theory of relativity, which deals with the very largest."

In laymen's term, he figured it out that two previously separately studied important physics theories are mathematically equivalent.

References

• Chen, C. and Kuljis, J. (2003) The rising landscape: A visual exploration of superstring revolutions in physics. Journal of the American Society for Information Science and Technology, 54 (5), 435-446.
• Chen, C. (2004) Searching for intellectual turning points: Progressive Knowledge Domain Visualization. Proceedings of the National Academy of Sciences of the United States of America (PNAS), 101 (Suppl. 1), 5303-5310.
• Chen, C., Chen, Y., Horowitz, M., Hou, H., Liu, Z., & Pellegrino, D. (2009). Towards an explanatory and computational theory of scientific discovery. Journal of Informetrics, 3(3), 191-209.