Millennium Relativity is a physics research project developed by Joseph A. Rybczyk. It presents a proposed theory intended to replace Einstein’s special and general theories of relativity by correlating classical and relativistic principles. The site describes the theory as the outcome of more than ten years of research into experimental evidence and outlines a progression of papers examining the foundations of classical and relativistic physics.

Its principal offering is a large collection of research papers, many available as PDF documents, covering topics such as motion, velocity and acceleration, inertia, gravity, energy, light propagation, Doppler effects, and the relationship between orbital and escape velocity. The articles also develop the project’s cause-and-effect approach to light speed, revisit concepts such as time dilation and distance contraction, and propose experiments related to debates about light-speed constancy. Visitors can explore the papers in their stated order, read a history of how the theory’s principles were developed, and access a forum featuring recent topics and contributions from other writers.