A recent IEEE Access Paper by Gunn, Allison and Abbott (GAA) proposed a new transient attack against the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange system. The attack is valid, but it is easy to build a defense for the KLJN system. Here we note that GAA’s paper contains several invalid statements regarding security measures and the continuity of functions in classical physics. These deficiencies are clarified in our present paper, wherein we also emphasize that a new version of the KLJN system is immune against all existing attacks, including the one by GAA.

A mathematical model for the purposes of methane hazard assessment in mines was developed in the Central Mining Institute as part of the statutory activities conducted in 2017 and 2018. The model describes the course of kinetics of methane sorption on coal samples while taking into account the diffusion coefficient. The paper presents the formulas describing the mathematical model of methane emission from coal sidewall to longwall working, taking into account the sorption properties of coal – sorption capacity of coal (related to methane) and the effective diffusion coefficient of methane in coal. In the light of the conducted research, such a methodology for describing this phenomenon enables a more precise determination of the amount of methane released to the longwall from the exploited coal seam, which in turn makes it possible to select appropriate methane prevention measures.

In this year we commemorate the 50 year anniversary of death of the outstanding Polish physical chemist professor Wojciech Świetosławski (1881–1968). His work was reviewed by prof. prof A. Dorabialska, K. Zieborak, W. Kemula and others. In this note one of his last and youngest students brings about reminiscences of the political problems he had to face, which could not have been described or even mentioned under the Soviet communist rule over Poland.

The main contradictions, between hypotheses posed by physical anthropologists or geneticists, and the hypotheses put forward by archaeologists or historians, regarding the origin and spread of the Slavs, concerned and still concern the following: (a) the state and biological dynamics of Slavic populations (the capacity for population expansion) , (b) diversity and biological similarity of various groups living in Central Europe at the end of antiquity and in the early Middle Ages, (c) migration movements and their intensity, (d) directions of migration and their importance in the formation of Slavic “ethnos”. On the basis of the results of anthropological research, it can be concluded that: (a) both in the late antiquity period and in the early Middle Ages, the regional diversity of the populations inhabiting the Odra and Vistula basins was maintained, (b) there was a geographical gradient in the variability of morphological features of the skull from west to east of Europe, (c) populations belonging to the Germanic population and populations living in Scandinavia in the Middle Ages clearly differed in terms of morphological features of the skeleton from the population of Western Slavs inhabiting the Odra and Vistula basin. On the other hand, the emergence of a clear geographical gradient in the variability of morphological features of the skeleton, in late antiquity and in the Middle Ages, in Central Europe, allows to conclude that there were no intense migratory movements and the population exchange between late antiquity and the early Middle (d) results of the skeletal morphological features and state and biological dynamics of the population from the Roman period and the Middle Ages indicate a similar level of adaptation of these groups of people to living conditions. This result does not confirm the thesis put forward by some archaeologists and historians that the cultural system of the Slavs was characterized by poverty and a low level of material culture.

Hydrological conditions in the region between the King George and Elephant Islands were defined on the basis of 24 STD measurements and 20 XBT profiles made in the time period from 26 October to 16 November 1986. In the entire investigated region the surface water temperature was below zero, often close to freezing point. The presence of summer modification of surface water with its characteristic thermal minimum was not found. Between the Scotia Front and the relatively well pronounced stream of geostrophic currents the anticyclonic meander was observed above the edge of the shelf at the depth of 100 m. Its spread was about 10 nM and within this meander the downwelling of surface water was noticed. As a compensating water movement, the upwelling of warmer waters was observed in the Drake Passage at 400 m.

The article presents a review of the researches on sea and atmospheric physics conducted by the Polish expeditions in Antarctica from 1977 to 1990.

The article analyses physicists’ attitudes towards philosophy on the examples of the positions of eminent theorists. There are two physicists’ philosophical attitudes towards philosophy: pro-philosophical (Einstein, Bohr, Heisenberg, von Weizsäcker, Penrose, Rovelli) and anti-philosophical (Weinberg, Hawking, Feynman). I analyse some physicists' arguments for or against philosophy. It is demonstrated that physicists are most critical of all philosophical conceptions that accept a priori factors in cognition, while those who recognize the significance of philosophy for science most often refer to the Pythagorean-Platonic tradition as the proper basis for understanding modern physics.