Real-Number Quantum Mechanics: Do We Still Need Imaginary Numbers?
German physicists have demonstrated a fully working quantum-mechanics formulation that uses only real numbers and can predict the same experimental outcomes as the standard complex-number framework, suggesting imaginary numbers aren’t fundamental to quantum mechanics but are still a convenient mathematical language. While the real-number approach matches all predictions, researchers note complex numbers remain useful in describing quantum systems, and this work revisits debates sparked by a 2021 Nature study on the necessity of complex numbers in quantum theory.
