  Since time immemorial, people have been looking for ways to organize
scientific knowledge into some systems to facilitate search and discovery of
new ideas. The problem was partially solved in the pre-Internet era using
library classifications, but nowadays it is nearly impossible to classify all
scientific and popular scientific knowledge manually. There is a clear gap
between the diversity and the amount of data available on the Internet and the
algorithms for automatic structuring of such data. In our preliminary study, we
approach the problem of knowledge discovery on web-scale data with diverse text
sources and propose an algorithm to aggregate multiple collections into a
single hierarchical topic model. We implement a web service named Rysearch to
demonstrate the concept of topical exploratory search and make it available
online.
