Observational locality: why is the speed of light invariant?

• 1、Faculty of Information Technology, Beijing University of Technology, Beijing 100124

Abstract：In 1905, based on the Michelson-Morley experiment, Einstein proposed the hypothesis of invariance of light speed (ILS). He then theoretically deduced the Lorentz transformation from ILS, established the theory of special relativity (SR), and revealed the relativistic phenomena of matter motion. Up till today, however, we still don\'t exactly know what role light plays in Einstein\'s theory, or why the speed of light is invariant; moreover, we still don\'t exactly understand relativistic phenomena. Based on the principle of observational locality (POL) and the hypothesis of observational limit (HOL), this paper has theoretically shown that, the Michelson-Morley experiment does not really mean ILS, but does demonstrate to us an significant phenomenon in physical observation: the speeds that observational media transmit the spacetime information about observed objects possess observational invariance. In Michelson-Morley experiment, light acts as both the observed object and the observational medium, and therefore, its speed is observationally invariant. The logical conclusions of this paper suggest that ILS is rooted from observational locality, is an observational effect and valid only when light acts as the messenger of observed information. Perhaps, this would provide new knowledge and understanding on the relativistic phenomena of matter motion..

Keywords： invariance of light speed, physical observability, locality, observational locality, relativistic effects