Question

Why do things weigh more when they have more potential energy in them (quantum mechanics/theoretical physics)?

Answer 1

In the realm of classical physics, potential energy alone does not contribute to an object's weight. Weight is typically associated with the force of gravity acting on an object's mass. However, in the context of quantum mechanics and theoretical physics, the relationship between potential energy and weight can become more nuanced. Let's explore a few key concepts:

1. Mass-Energy Equivalence: In Einstein's theory of relativity, the famous equation E=mc² establishes a connection between mass (m) and energy (E). It implies that mass and energy are interchangeable and can be converted into one another. So, in certain scenarios involving high-energy processes or relativistic effects, the potential energy within a system can contribute to its total mass.

2. Quantum Field Theory: In the framework of quantum field theory, particles are described as excitations of quantum fields permeating space. These fields interact with each other, and their interactions can give rise to potential energy. In this context, the potential energy associated with fields can contribute to the overall energy and mass of a system.

3. Gravitational Potential Energy: In general relativity, gravitational potential energy can affect the curvature of spacetime and, therefore, the motion of objects within that spacetime. Mass and energy (including potential energy) contribute to the curvature of spacetime, which determines how objects move under the influence of gravity. However, it is important to note that the contribution of potential energy to an object's weight in this context is indirect and related to how spacetime itself is affected.

It's crucial to highlight that the relationship between potential energy, weight, and mass in the realm of quantum mechanics and theoretical physics can be highly complex and dependent on specific scenarios and theoretical frameworks. The topic of mass-energy equivalence and the effects of potential energy on weight require a deeper understanding of quantum field theory, general relativity, and the interplay between these theories.