Why Can't We Say That Electrons are Negatively Charged and Protons are Positively Charged?

This is a pure convention. Electrodynamics is perfectly symmetrical. The symmetry suggests that if someone were to flip the signs of charged particles, our world would still function identically. The convention we use today is, in a way, an arbitrary choice made by early scientists to simplify their understanding and notation.

Charge is Relative

Charge is relative in the sense that it can be understood through the context and relationship of particles. In the Copenhagen interpretation, charge translates to mass. When we look at an atom, the nucleus (made up of protons) is more massive than the electrons orbiting around it. Thus, we assign the electrons a negative charge and the nucleus a positive charge. This relationship of mass and charge explains why they behave as they do.

Considering the same principles, if you bring two nuclei together, they repel each other due to their positive charges. Similarly, like charges on any particles, including photons, result in repulsion. This fundamental relationship holds true at a basic level and extends to a more complex understanding of charge in particle physics.

Protons and Quarks

Protons derive their positive charge by the summation of the charges of their constituent quarks. Quarks are fundamental particles, meaning their structure cannot be broken down further without changing their nature. Electrons, on the other hand, are already negatively charged and do not undergo an analogous charge-sourced transformation.

With fundamental particles, the question of why they are as they are often leads to the simple answer, “that is what they are.” This answer reflects the limitations of current understanding and the inherent properties of these particles that define their behavior.

Antiparticles and Charge Polarity

The concept of polarity in charge can also be seen in antiparticles. Antiprotons have the opposite polarity to protons, and antielectrons (positrons) have the opposite charge to electrons. These anti-particles can exist and are important in various physical processes, such as particle annihilation. When electrons and positrons come into contact, they annihilate each other, as do protons and antiprotons.

Historically, the early universe was believed to have roughly equal numbers of particles and antiparticles. Shortly after the Big Bang, these particles annihilated each other in vast quantities, leaving behind the fundamental particles we see today. This process is one of the reasons we currently observe the specific distribution of charges in the universe.

Quantum Observations and Naming Conventions

There are some interesting observations and theories regarding the stability and scale of charges. For example, on the Quantum Heretics website, a suggestion is made that the difference in the stability and scale of charge between electrons and protons might be related to the size and mass of these particles. Such ideas, while interesting, are largely based on observation rather than a definitive explanation.

The naming of charges, positive and negative, is largely a matter of convention. While it can be useful for description and practical applications, the symmetry of the universe suggests that reversing these conventions would not fundamentally alter the workings of the world.