Theories on the Formation and Evolution of Black Holes & Galaxies

Conventional theory suggests that black holes are singularities of enormous mass-density: matter compressed beyond imagination due to extreme mass-based gravitational forces and possessing so much mass-based gravity that light itself cannot escape them. As an alternative to convention, this paper builds on the theories of fire-tornado accretion cylinder vortex forces and colossal magnetic pressure spawned within (previously described by the authors in their paper on ~2D planar celestial kinematics), and analyzes them in more detail specifically for black holes and the formation / evolution of galaxies. Several interesting charge-distribution and associated electromagnetic field components will be utilized in the modeling. To demonstrate concept, the proposed forces during formation and evolution will be computationally modeled and translated into visual simulations in 4-D space-time using C# programming in the Unity operating platform.

Nuclear Physics and Astrophysics Constraints on the High Density Matter Equation of State

(1) This review has been written in memory of Steven Moszkowski who unexpectedly passed away in December 2020. It has been inspired by our many years of discussions. Steven’s enthusiasm, drive and determination to understand atomic nuclei in simple terms of basic laws of physics was infectious. He sought the fundamental origin of nuclear forces in free space, and their saturation and modification in nuclear medium. His untimely departure left our job unfinished but his legacy lives on. (2) Focusing on the nuclear force acting in nuclear matter of astrophysical interest and its equation of state (EoS), we take several typical snapshots of evolution of the theory of nuclear forces. We start from original ideas in the 1930s moving through to its overwhelming diversity today. The development is supported by modern observational and terrestrial data and their inference in the multimessenger era, as well as by novel mathematical techniques and computer power. (3) We find that, despite the admirable effort both in theory and measurement, we are facing multiple models dependent on a large number of variable correlated parameters which cannot be constrained by data, which are not yet accurate, nor sensitive enough, to identify the theory closest to reality. The role of microphysics in the theories is severely limited or neglected, mostly deemed to be too difficult to tackle. (4) Taking the EoS of high-density matter as an example, we propose to develop models, based, as much as currently possible, on the microphysics of the nuclear force, with a minimal set of parameters, chosen under clear physical guidance. Still somewhat phenomenological, such models could pave the way to realistic predictions, not tracing the measurement, but leading it.

Achieving Sustainable Development Goals in Bangladesh: Does Population Density Matter?

Bangladesh, one of the most densely populated countries in the world with a density of about 1,265 persons per km2 having a limited land area with high development potential. Being able to accomplish noteworthy achievements in MDGs, Bangladesh is heading towards achieving the targets of the SDGs amid several challenges like high population, resource constraints, poverty etc. This study aims at addressing the challenges and prospect of increasing population density in achieving the SDGs. An exploratory approach has been applied to address how the density of population might influence the achievement of the SDGs. Data on population and other relevant parameters have been identified from census, published documents and articles. The current progress of SDGs attainment shows some of the goals are on track, but more progress could have been achieved unless being hindered by the high density of population. Feeding and providing the basic amenities to this huge population is quite a big challenge with limited resources, in contrast, optimum utilization of the demographic dividend by ensuring effective participation of the young active population in the current development process can also expedite the progress of attainment of SDGs. The adversities of the high density of population can essentially be offset by redistribution of urban population and decentralization of economic activities from major cities. Alongside appropriate and precise policy measures, comprehensive study on quantifying how the density of population is affecting the attainment of SDGs is recommended. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 8(2), 2019, P 1-15

The need for speed

This paper reviews the challenges posed by the physics of the interaction of high-peak power femtosecond lasers with ultrathin foil targets. Initially designed to produce warm solid-density plasmas through the isochoric heating of solid matter, the interaction of an ultrashort pulse with ultrathin foils is becoming more and more complex as the laser intensity is increased. The dream of achieving very hot solid density matter with extreme specific energy density faces several bottlenecks discussed here as related to the laser technology, to the complexity of the physical processes, and to the limits of our current time-resolved instrumentations.