Extensive social media usage causes psychological dependence and impacts people’s self-evaluations. It is vital to seek possible buffers to social media addiction’s detrimental effect on self-esteem and body image. Poland has one of the highest scores on problematic social media usage. Past studies pointed to narcissism and self-compassion as possible mediators of such effects. The present study aimed to explore Polish individuals’ (N=527) social media usage habits. We hypothesised gender differences and social media addiction predictive effect on self-evaluations (self- esteem, body image), with narcissism and self-compassion as mediators of such relationships. The results revealed that only visual media (Facebook, Instagram, TikTok) had a negative effect on self-evaluations and that women reported more social media addiction and decreased self-esteem, self-compassion and body image. Social media addiction was negatively predicting body image for both genders and self-esteem for women but not for men, with self-compassion and narcissism mediating such relationships.

The minimum-time problem for a glider flying in the vertical plane is considered. The glider is regarded as a particle moving in the atmosphere in given thermal conditions. The problem is formulated in optimal control and solved using direct pseudospectral Chebysev's method. The data are taken for the Word Class Glider PW-5 "Smyk". Computed optimum results are compared with glider's trajectories from the Second Domestic Glider Championship 2006, Suwałki, Poland.

The article discusses the concentration of Martin Luther’s theology on the Christian existence. There are three main areas pointing to this key idea. Firstly, the description of justification of the people in the categories of freedom gained through the experience of faith, which leads to a thankful service towards one’s neighbour. Secondly, sacramental understanding of the working of God’s Word as a performative that changes the world. It defines not only the understanding of the sacraments, with the key role of Baptism as a foundation for everyday actualisation of Christian life in penance, which strives for fighting off the sinfulness of an old, sinful man, and leads to building the man’s own justice based on the alien justice of Christ, but it is also the basis for the communion of believers – the church, as well as for the orders of creation, which structure the current reality. Thirdly, the remarks on theological knowledge closed in the triad prayer–meditation–temptation and theological weight of the experience of differentiating between the Law and the Gospel.