Quantum field theory lecture by Tobias Osborne (2017) mentions that quantization is a guess.
This is one of the first examples in most quantum field theory.
It usually does not involve any forces, just the interpretation of what the quantum field is.
www.youtube.com/watch?v=zv94slY6WqY&list=PLSpklniGdSfSsk7BSZjONcfhRGKNa2uou&index=2 Quantization Of A Free Real Scalar Field by Dietterich Labs (2019)
Articles by others on the same topic
Quantization in physics refers to the process of transitioning from classical physics to quantum mechanics, where certain physical properties are restricted to discrete values rather than continuous ranges. This concept is foundational to quantum theory, which describes the behavior of matter and energy on very small scales, such as atoms and subatomic particles. Key aspects of quantization include: 1. **Energy Levels**: In quantum mechanics, systems like electrons in an atom can only occupy specific energy levels.