No, wave-particle duality is not considered an outmoded idea in physics. It remains a fundamental concept in quantum mechanics, which is one of the most successful and extensively tested theories in the history of science.
Wave-particle duality refers to the observation that particles such as electrons and photons can exhibit both wave-like and particle-like properties depending on the experimental setup. This duality is supported by numerous experiments and has been verified through the predictions and calculations of quantum mechanics, which have been confirmed by a wide range of empirical data.
Wave-particle duality is not just a theoretical concept but has practical applications as well. For example, the understanding of wave-particle duality is crucial in the development of technologies like electron microscopy, which utilizes the wave-like behavior of electrons to achieve high-resolution imaging.
While there may be ongoing debates and discussions among physicists about the interpretation and philosophical implications of quantum mechanics, the concept of wave-particle duality itself remains a well-established and foundational principle in the field. It is widely accepted and forms the basis for our understanding of the microscopic world.