In a multi-fold universe, gravity emerges from Entanglement through the multi-fold mechanisms. As a result, gravity-like effects appear in between entangled particles that they be real or virtual. Long range, massless gravity results from entanglement of massless virtual particles. Entanglement of massive virtual particles leads to massive gravity contributions at very smalls scales. Multi-folds mechanisms also result into a spacetime that is discrete, with a random walk fractal structure and non-commutative geometry that is Lorentz invariant and where spacetime nodes and particles can be modeled with microscopic black holes. All these recover General Relativity (GR) at large scales and semi-classical model remain valid till smaller scale than usually expected. Gravity can therefore be added to the Standard Model. This can contribute to resolving several open issues with the Standard Model. The present paper examines what can be said of time in a multi-fold universe: what is the notion of time, does it exist or make sense and is it continuous or discrete and is there an arrow of time? In particular, we discuss how multi-fold universe handles the well-known time problem, the Bryce Wheeler equation as well as the explanations proposed so far by Page and Wootters and the subsequent rigorous expansions of Gambini and Pullin. In a multi-fold universe, time can concretely exist both because of entanglement and its random walk constructive nature that renders spacetime, including time discrete, fractal and non-commutative within a spacetime geometry, yet become not observable at larger scales. Therefore, random walks and entanglement concretize time and entanglement is also responsible for the arrow of time: the multi-folds mechanisms are irreversible, yet they can appear reversible if not fully modeled, which explains why Quantum Physics and GR appear essentially reversible. When putting all these consideration together it becomes clear that random walks and entanglement not only generate and shape spacetime but they also are at the core of the concept of time and how it can be perceived by us.
60 years of broken symmetries in quantum physics (from the Bogoliubov theory of superfluidity to the Standard Model)
