  Academic research is driven by several factors causing different disciplines
to act as "sources" or "sinks" of knowledge. However, how the flow of authors'
research interests -- a proxy of human knowledge -- evolved across time is
still poorly understood. Here, we build a comprehensive map of such flows
across one century, revealing fundamental periods in the raise of interest in
areas of human knowledge. We identify and quantify the most attractive topics
over time, when a relatively significant number of researchers moved from their
original area to another one, causing what we call a "diaspora of the
knowledge" towards sinks of scientific interest, and we relate these points to
crucial historical and political events. Noticeably, only a few areas -- like
Medicine, Physics or Chemistry -- mainly act as sources of the diaspora,
whereas areas like Material Science, Chemical Engineering, Neuroscience,
Immunology and Microbiology or Environmental Science behave like sinks.
