No-go theorems

No-go theorems are mathematical results in physics that show certain ideas or possibilities cannot happen under specific conditions. They set fundamental limits, proving that some concepts—like certain types of interactions or theories—are impossible within current understanding. For example, they can demonstrate why a particular approach to unifying gravity and quantum mechanics won't work, guiding scientists to focus on viable paths. Essentially, no-go theorems clarify what cannot be done, helping to focus research on promising directions by ruling out impossible options.