In 1905, Einstein carried out his first derivation of the mass–energy equivalence by studying in different reference frames the energy balance of a body emitting electromagnetic radiation and assuming special relativity as a prerequisite. In this paper, we prove that a general mass–energy relationship can be derived solely from very basic assumptions, which are the same made in Einstein’s first derivation but completely neglecting special relativity. The general mass–energy relationship turns to a mass–energy equivalence when is applied to the case of a body emitting energy in the form of electromagnetic waves. Our main result is that if the core logic behind Einstein’s approach is sound, then the essence of the mass–energy equivalence can be derived without special relativity. We believe that our heuristic approach, although not capable of giving the exact mathematical formula for the mass–energy equivalence, may represent a useful addition to the general discussion on the matter at the graduate level. Our finding suggests that the connection between mass and energy is at a deeper level and comes before any full-fledged physical theory.

1905年，爱因斯坦通过在不同的参考系中研究发射电磁辐射的物体的能量平衡，并以狭义相对论为前提，首次推导了质量-能量当量。在本文中，我们证明了一般的质能关系可以仅从非常基本的假设中得出，这些假设与爱因斯坦的一阶推论相同，但完全忽略了狭义相对论。当应用于以电磁波形式发射能量的物体时，一般的质量-能量关系变成了质量-能量等价关系。我们的主要结果是，如果爱因斯坦方法背后的核心逻辑是合理的，那么就可以推导出质能等效性的本质，而无需狭义相对论。我们相信我们的启发式方法 尽管不能提供精确的数学公式来表示质量-能量当量，但它可能是对研究生级别的一般性讨论的有益补充。我们的发现表明，质量与能量之间的联系处于更深层次，并且早于任何成熟的物理理论。