Experimental Apparatuses Aiming to Investigate the One-Way Speed of Light
Faculty Mentor Information
Dr. Skipper Kagamaster, Northwest Nazarene University
Presentation Date
7-16-2026
Abstract
This project analyzes whether proposed motion-based apparatuses can provide useful information about the one-way speed of light. Unlike the two-way speed of light that only needs one clock by timing a reflected signal, a one-way measurement requires two spatially separated clocks. This introduces synchronization issues because the result depends on how those clocks are synchronized. Conventionally, the one-way speed of light is treated as synchronization-dependent rather than directly measurable. This project examines two apparatuses: a linear moving rail system with inward-facing light sensor arrays and a disconnected, offset light source positioned between the rails, and a rotating ring-shaped apparatus with an interior light source and a sensor array lining the inside of the ring. Each design will be analyzed by Einstein's synchrony convention which assumes an isotropic one-way speed of light, and by alternative synchronization conventions which allow direction-dependent one-way speeds while preserving the measured two-way speed of light. The project aims to evaluate these apparatuses from both the laboratory and moving reference frames to determine if the light sensor data will result in a synchrony-independent result or reflect the chosen synchrony convention. The analysis will show how experimental design, reference frames, and synchronization assumptions must be separated when investigating the one-way speed of light.
Experimental Apparatuses Aiming to Investigate the One-Way Speed of Light
This project analyzes whether proposed motion-based apparatuses can provide useful information about the one-way speed of light. Unlike the two-way speed of light that only needs one clock by timing a reflected signal, a one-way measurement requires two spatially separated clocks. This introduces synchronization issues because the result depends on how those clocks are synchronized. Conventionally, the one-way speed of light is treated as synchronization-dependent rather than directly measurable. This project examines two apparatuses: a linear moving rail system with inward-facing light sensor arrays and a disconnected, offset light source positioned between the rails, and a rotating ring-shaped apparatus with an interior light source and a sensor array lining the inside of the ring. Each design will be analyzed by Einstein's synchrony convention which assumes an isotropic one-way speed of light, and by alternative synchronization conventions which allow direction-dependent one-way speeds while preserving the measured two-way speed of light. The project aims to evaluate these apparatuses from both the laboratory and moving reference frames to determine if the light sensor data will result in a synchrony-independent result or reflect the chosen synchrony convention. The analysis will show how experimental design, reference frames, and synchronization assumptions must be separated when investigating the one-way speed of light.