A timeless quantum mechanics?

CRISTIAN LÓPEZ

Buenos Aires

Workshop; International Workshop on Ontology of Quantum Mechanics,; 2017

There seems to be a broad agreement that quantum mechanics is blind to the passage of time, as its fundamental dynamical equation, the Schrödinger equation, is time-reversal invariant. Nothing at the formal level of the theory would allow us to discriminate the past-to-future direction from the future-to-past one. Such a conclusion is quite disappointing for those particularly interested in grounding the asymmetric nature of time on the world: quantum mechanics seems to suggest that we live in a Parmenidean world, where time-asymmetry is just an illusion.In this talk, I will take a stand against such received wisdom. I will not argue that the Schrödinger equation is actually non-time-reversal invariant, meaning that tradition has been deeply wrong by claiming the opposite. Instead, the point I want to make is that the problem is even prior and deeper: the very concept of time-reversal has been, at least, misunderstood when the problem of the arrow of time is at issue. This misunderstanding lies, as I shall argue, on how the nature of time-reversal has been formally understood in fundamental physics, particularly, in quantum mechanics. The main aim of this paper is to reveal and to disentangle that misunderstanding, and to bring the discussion about time-reversal invariance back on the track of the arrow of time.