Quantum mechanics (QM) does not define space as "nothing" or non-existent; rather, it operates within a framework of ordinary three-dimensional space and time. The discussions highlight that space is often described in terms of fields, such as the Higgs field or string theory, but these concepts remain speculative and lack experimental proof. QM itself does not provide a clear layman's definition of space, as the terms used to discuss existence and reality are not well-defined in scientific discourse. The nature of space-time is better addressed in general relativity, which treats it as a flexible, continuous manifold influenced by matter. Overall, the conversation underscores the complexity and philosophical implications surrounding the understanding of space in the context of quantum physics.