This booklet is a collection of texts from author in the realm of cosmology and quantum physics. A variety of themes are covered in the book, as the cosmic-distance duality, wave functions and particle-wave duality, the Roche sphere and Archimedean buoyancy as key principles underpinning cosmic transparency, the connection between Bohr model and Larmor formula, the ladder to the hypersphere as a sequence of space geometry, the connection between the cosmic horizon and Bohr radius, ring theory, etc.