Time can be at the secret scope like energy. None of us who are used to the physical approach can really understand them yet. However, It becomes cristal clear that there are two domains of the scope: physical and virtual states or worlds. In our physical view, it lies at the heart of multi-states within one universe: a duality of virtual and physical reality. The issue at our current theory is that the multi-worlds under one universal topology are collapsed into an observable state, which results in our morden thoery is also collapsed into the physical existence only.
Therefore, the multi-worlds within an oneness universe should be the critical thinking point. For example, spacetime manifold has been moldeled purely in physical framework only, which is clearly diluted the virtual independence as well as reciprocity. In this physical model, we can only have a part of the behaviors, for example the virtual dimension: ct. What does ct mean??? Following this approach, scientists have beem researching for more than a century on unified field theory or theory of everything. So does the arguments for the time and energy. The point is we can't understand how the virtuality works, or even worse that most of us doesn't even realize there is a virtual word nor a duality of virtual and physical entanglement.
It means, in reality, the virtual property of time appears in our physical word is a pair of virtual images: [math]{\bf r}\pm ict[/math] In our nature, we have a reciprocal par of the complex manifold before it is collapsed the three dimensions of space and the one dimension of time into a single four-dimensional continuum space, or Minkowski space: [math]{\bf r}-ct[/math]
With this simple concept, the natural duality appears recently the groundbreaking in unified field theory... (BTW: if interested, I can provide the links to a set of the papers for the groundbreaking's)