The Simplest Derivation of Einstein's Equation of Mass-Energy Equivalence

The principle of mass-energy equivalence is one of the most profound insights in physics, revealing that matter is simply another form of energy. Yet, more than a century after its discovery, this concept remains unfamiliar to the general public. This disconnect may stem from the lack of clear and comprehensive explanations that make the principle accessible beyond academic settings. Simplified derivations of the mass-energy equation can help bridge this gap, making the underlying concepts more approachable and understandable for a broader audience.