V vs Relativity Lab

Build and observe to come true with figures of repulsion, geometry, angles. V-SPER, free application, is a support for the teaching of the VSPER theory (Valence Shell Electron Pair Repulsion). This theory makes it possible to predict the geometry of molecules from the sole electrostatic repulsion of valence electron pairs. It is based on the Lewis model of distribution of the valence electrons of the atoms concerned. The latter is a prerequisite to take full advantage of V-SPER. The molecule is denoted AXnEm. The atoms (or portions of molecules) linked to the central atom A are denoted X (n: number of X, whether they are linked by single or multiple bonds). The non-bonding electron pairs belonging to the central atom A and not being involved in bonds are denoted E (m: number of E). V-SPER allows to build simple and 3D objects (molecules) and to display the repulsion figure in blue (FigREP), the molecular geometry in yellow (Geom) as well as the angles. Some angles are just modeled and do not always correspond to experimentally measured angles, such as the relative lengths of single or multiple bonds

Relativity Lab is a professional educational app designed to help students, teachers and science enthusiasts explore the ideas of Einstein’s relativity and modern cosmology through structured learning, interactive simulations and visual explanations. The app covers special relativity, general relativity, GPS clock correction, gravitational waves, black holes, famous experiments, physics dictionary support, guided learning routes, classroom teaching tools and a full Cosmology Institute. FEATURES Einstein Academy Follow a structured learning pathway covering key concepts in relativity, spacetime, time dilation, gravity and modern physics. Interactive Relativity Lab Use visual simulations to explore abstract physics ideas in a clearer and more practical way. GPS Relativity Learn why satellite navigation needs relativistic correction and how tiny timing differences matter in real engineering. Solar System Relativity Compare relativistic effects across different objects and gravitational environments. Black Hole Explorer Explore event horizons, photon spheres, strong gravity and key black-hole concepts using educational visual tools. Gravitational Waves Understand inspiral, merger and ringdown stages, and learn how spacetime ripples connect to Einstein’s theory. Famous Experiments Review major experimental evidence including the 1919 eclipse test, Mercury’s perihelion, GPS verification and gravitational wave detection. Physics Dictionary Search and review important terms in English, Traditional Chinese and Simplified Chinese. Cosmology Institute Explore the Big Bang, Hubble’s Law, redshift, dark matter, dark energy, cosmic microwave background, observatory missions, research tools, visual simulations and guided learning paths. Teacher and Classroom Mode Use lesson planning tools, student activity sheets, discussion prompts and assessment rubrics for classroom-style learning. Portfolio and Mastery Tools Complete quizzes, revision cards, learning portfolios, milestone summaries, screenshot planners and certificate preparation tools. Relativity Lab is designed for educational use. It uses simplified models and visualisations to support understanding. It is not intended to replace formal scientific analysis, professional research software or official academic instruction.