Selected Theses on Science

peer reviewedThe purpose of Science is to achieve the truth on the way to a new knowledge. The truth, as Immanuel Kant wrote, is the correspondence of knowledge with its object. However, the key question is how to “find a universal and true criterion of the truth of all knowledge”? The contribution of the fundamental sciences is extremely important. And here, in my opinion, there appears a modern paradox which has globally changed the public consciousness. On the one hand, the fundamental science went into the status of the labor forces and, on the other hand, modern production, demanding “the implementation of scientific research and scientific approach, began increasingly resemble to science.” In the process of production—which creates the product of labor including both material goods and services in the case of material production and a new knowledge as in the case of science—the labor forces enter into industrial relations. If any scientific work as an object, an element of the external world that we aim to contemplate the work, as well as a phenomenon, and develop its conceptual representation as well as about the phenomenon that it is modeling. Hence, the closer to the actual simulated phenomenon to the studied one, the closer this work to the truth. I assume my viewpoint is quite clear, even without mentioning Goethe: “It is a shame that the truth is so simple.”. © 2018, Springer International Publishing AG, part of Springer Nature

Active galactic nuclei: what’s in a name?

Active Galactic Nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique observational signatures that cover the full electromagnetic spectrum over more than twenty orders of magnitude in frequency. The rich phenomenology of AGN has resulted in a large number of different "flavours" in the literature that now comprise a complex and confusing AGN "zoo". It is increasingly clear that these classifications are only partially related to intrinsic differences between AGN, and primarily reflect variations in a relatively small number of astrophysical parameters as well the method by which each class of AGN is selected. Taken together, observations in different electromagnetic bands as well as variations over time provide complementary windows on the physics of different sub-structures in the AGN. In this review, we present an overview of AGN multi-wavelength properties with the aim of painting their "big picture" through observations in each electromagnetic band from radio to gamma-rays as well as AGN variability. We address what we can learn from each observational method, the impact of selection effects, the physics behind the emission at each wavelength, and the potential for future studies. To conclude we use these observations to piece together the basic architecture of AGN, discuss our current understanding of unification models, and highlight some open questions that present opportunities for future observational and theoretical progress.Comment: Accepted for publication in Astronomy & Astrophysics Review, 56 pages, 25 figure