Einstein’s theory of special relativity (SR) is well established, and it asserts that infinite resistance is exerted on matter when it approaches the speed of light. Therefore, the established classical link between mass and inertia is profoundly inaccurate. The resistance exerted by spacetime on to the matter does not agree with the interpretation of classical mechanics. However, application of Newtonian physics to detect the mass of a high-speed particle, by its kinetic energy, will result in the wrong measurement. We use inertia or gravity as a tool to identify the mass of matter.
