Einstein’s renowned mass-energy relation (E=mc²) signifies that a certain mass represents a quantity of energy, and conversely, that a quantity of energy corresponds to a specific mass.

A (quantum) system that emits energy loses mass.

When a particle and its antiparticle annihilate, all mass disappears, taking the form of energy.

Energy in terms of relation physics: The amount of (potential) energy in a quantum system is the sum of the probability of all (potential) changes in that system.

Mass in terms of relation physics: The mass of a quantum system reflects the complexity of the superposition of information in the system and, consequently, the (im)probability with which it can exchange information.

On both sides of the mass-energy relation equation lies potential change. On the left, it emphasizes the revenues, while on the right, the focus lies costs.

Energy and mass are two sides of the same coin. Energy focuses on possibilities, while mass concentrates on difficulties.

In the equation, c² represents the square of the speed of light. The speed of light (m/s or length/time) is a macroscopic concept. On the macro level, we look at either time (T) or space (L, length). However, on the quantum level, this distinction does not exist. There, it’s one and the same, T=L, and in this context, c² = (L/T)² = 1.

For quantum information, the equation is simple; not exciting. The mass-energy relation becomes more intriguing on the macro level. Mass is a macroscopic concept, after all.