Universe: everything in the intuitive sense... lol Space: uhh hmm well I'll get back to you on that maybe. Matter: Anything that one might say is composed of particles of spin 1/2? Like Niels Bohr said: "Every sentence I utter must be understood not as an affirmation, but as a question." Have you read Christoph Schiller's speculation on unification? Motion Mountain - Downloading the Free Physics Text 6th volume specifically
universe - anything disturbed by the expansion wave from the "big bang" space - the medium resulting from the disturbance matter - manifestation of energy, from the disturbance