Input: Simulate a debate between 2 physicists arguing over the validity of renormalization in quantum field theory
Physicist 1: “Renormalization is a crucial part of quantum field theory and has been extremely successful in predicting and explaining a wide range of physical phenomena. Without it, we wouldn’t be able to make precise predictions about the behavior of particles at high energies.”
Physicist 2: “While I agree that renormalization has been useful in some cases, I think it’s important to also consider the limitations of this approach. It relies on the idea of infinite quantities, which is problematic from a mathematical standpoint. There have also been alternative approaches proposed, such as perturbative quantum gravity, that don’t require renormalization and might be worth considering.”
Physicist 1: “I agree that there are some conceptual issues with renormalization, but it’s important to remember that it has been extremely successful in practice. It’s allowed us to make predictions that have been confirmed by experiments to high precision. Until we have a better alternative that can make similarly accurate predictions, I think it’s still the best tool we have.”
Physicist 2: “I agree that the predictive power of renormalization can’t be denied, but I also think it’s important to keep an open mind and consider other approaches. The concept of infinity is something that has caused problems in other areas of physics, such as the black hole information paradox, and I think it’s worth exploring whether there might be a way to avoid it in quantum field theory as well.”
Input: Now an observer states that he heard there is more than one way to choose renormalization constants and asks the physicists if that makes the whole idea more suspicious
Physicist 1: “It’s true that there are multiple ways to choose the renormalization constants, but this is actually a feature rather than a flaw of the theory. The constants are introduced to absorb infinities that arise in perturbative calculations, and the choice of constants is somewhat arbitrary. Different choices of constants correspond to different renormalization schemes, which can give different results for physical quantities. However, it can be shown that the scheme dependence of the predictions goes away in the limit of infinite orders of perturbation theory, so the predictions become independent of the choice of scheme at high enough orders.”
Physicist 2: “I see what you’re saying, but I think it’s important to recognize that this scheme dependence is still present at any finite order of perturbation theory. It’s not uncommon for different schemes to give significantly different results for physical quantities at lower orders. This can be a source of uncertainty and makes it more difficult to compare predictions made using different schemes. It’s also worth noting that some schemes are more convenient to use in certain cases, such as the minimal subtraction scheme, which is often used because it simplifies calculations.”