Karolina Rożko

The main purpose of this article is to show some processes of the growth of knowledge. An astrophysical case: a problem of planets around pulsars formation is studied. In the first part reasons for taking this problem are presented. Then some historical facts about discoveries of planets around pulsars are mentioned. The paper focuses on three cases: PSR1257+12, PSR1620-26 and PSR J 1719-1438. In second part of the article the changes in the theoretical point of view, which occured during the last twenty years, are presented. At the end the attempt is made to describe the process of the growth of the planets around pulsars within the framework of formation.

The main aim of this article is to show how the notion of refutation has been changing in logic for the last few years. The idea of refutation was known to Aristotle, but the formal concept was introduced by Jan Łukasiewicz. Afterwards this notion was investigated by the Polish group of logicians headed by Jerzy Słupecki. Several interesting articles about refutation have appeared in the last years. In this article, I present in outline the history of the notion of refutation and I discuss recent applications of refutation systems both in the theoretical and practical approach