On the scientific method learned from Albert Einstein in 2005 -- the World Year of Physics
On the Soviet Contribution to the Discovery of Quark Color (Against One False Revision)
On the Status of the Geodesic Principle in Newtonian and Relativistic Physics
On the telescopic disks of stars - a review and analysis of stellar observations from the early 17th through the middle 19th centuries
On the verge of Umdeutung in Minnesota: Van Vleck and the correspondence principle (Part One)
On the verge of Umdeutung in Minnesota: Van Vleck and the correspondence principle (Part Two)
On Wave-Particle Duality
On Wolfgang Pauli's most important contributions to physics
Operational Quantum Mechanics, Quantum Axiomatics and Quantum Structures
Operational understanding of the covariance of classical electrodynamics
Orientation of the northern gate of the Goseck Neolithic rondel
Orientations of the Giant's Churches in Ostrobothnia, Finland
Orthodoxy and Heterodoxy in the Research on the Foundations of Quantum Physics: E. P. Wigner's Case
Otto Stern (1888-1969): The founding father of experimental atomic physics
P.A.M. Dirac and the Discovery of Quantum Mechanics
Parity non-conservation in beta-decay of nuclei: revisiting experiment and theory fifty years after. IV. Parity breaking models
Parmenides reloaded
Particle crossing versus field crossing; a corrective response to Duff's recent account of string theory
Pascual Jordan's legacy and the ongoing research in quantum field theory
Pascual Jordan's resolution of the conundrum of the wave-particle duality of light