1.1.5.1. Imaginary Time?
Stephen Hawking's quantum cosmology uses "imaginary time" as more fundamental than "real time". The principle of causality only makes sense in real time where there are light cones at each spacetime point event. It is violated in imaginary time. The missing mass enigma may be a clue that real time is only the top of an iceberg. Most of the universe may still exist in imaginary time.
Mathematically spacetime is described by a metric tensor which has a topological property called the "signature". The light cone only exists in real time where the signature is -+++. There is no light cone in imaginary time where the signature is ++++. The phase transition from imaginary to real time which starts the Big Bang is a topological transition. Is it controllable from the far future of real time in a self-consistent loop?
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