Big data (very large data sets) are increasing in an accelerating speed. More and more data is also becoming freely available. This article is an overview of this progress and data sources related to molecular biology and public health especially from the Finnish perspective. Finland has several excellent data sources that are currently not used effectively. Big data has already produced major benefits especially in molecular biology, but benefits in public health and individual choice are only now being materialised. The paradigm in research may change dramatically, if the effort switches from article production to the production of knowledge crystals, i.e. collaborative data-based answers to research questions. Also the role of a clinician is becoming more like that of a coach.