Unfortunately, one can't zoom into the fields, that would be really cool.
I came across the site via this paper
- Mapping the backbone of science
By Kevin Boyackm Richard Klavans and Katy Boerner
Scientometrics, Vol. 64, No. 3 (2005) 351.374
which is quite visionary in its aims. Here is a quote from their conclusions:
"The disciplinary map presented here is designed to support decision-making, e.g., the allocation of resources among/between disciplines. However, it also promotes the understanding and teaching of the general structure of science. Although it is a static map, and thus does not reveal how disciplines are born, evolve, or die, it is the broadest static map of science published to date, and thus constitutes another step forward in the study of the structure and evolution of science by scientific means.
Ultimately, maps of science could be based on a much broader set of data (such as scholarly journals, proceedings, patents, grants, and funding opportunities). Alternative units of analysis (clusters of journals, papers, authors, funding sources and/or text) could be generated to address different user needs. Instead of being static, dynamic maps could be generated that show high activity, scientific frontiers, and merging/splitting of scientific areas.
We believe that these global maps of science will enable researchers and practitioners to search for and benefit from results and expertise across scientific boundaries, counterbalancing the increasing fragmentation of science and the resulting duplication of work. These maps of science could also serve as a common data reference system for scholars from all disciplines - analogous to how geologists use the earth itself to index and retrieve data, documents, and expertise, or to how astronomers use astronomical coordinates. If such a reference system were to exist, all researchers could have a bird's eye view of the landscape of science, and could use this landscape to navigate to areas of interest, to communicate results, and to announce discoveries.
This global view - as opposed to doing keyword based searches on the Web or in digital libraries with very little information about the coverage of the queried database or the quality of the result - would give many more people access to scientific results. This, in turn, would lead to more informed citizens and a faster spread of results and practices benefiting all of humanity."