By using non-dimensional Navier–Stokes equations in systems where partial modelling complications can be avoided, it is shown that geometrically similar systems can exhibit identical behaviour but according to different time scales where the latter are also within our own control. These models indicate that the physical nature of time is not related to a fundamental constant, but the passage of time can have a different but still constant value in a particular system of our own choosing. This observation also adds to our knowledge relating to the dichotomy of interpreting time either as a flowing parameter or, alternatively, just accepting it as a part of space-time. The observation adds evidence in favour of both viewpoints. The conclusions also seem relevant to biological species, chemical processes in general and other branches of physics. Using earlier work of Prigogine and others, it also appears that instantaneous time has important properties dividing past and future time into two segments which differ fundamentally in physical characteristics. This seems to explain the ‘raison d’tre’ of the second law of thermodynamics and the necessarily asymmetrical nature of time in our own world where mathematical symmetry of physical laws is the norm. This entropic time barrier also seems to explain the physically intangible nature of past events and their possible natural importance as former lower entropy forms of existence. It is concluded that these physical features of time are necessary for the existence of any form of life and Darwinian evolution, in particular. The conclusions may also help to throw further light on other suggested theories and observations in physics and the role of quantum decoherence in life and its adaptive ability.
causality, cosmological time, entropy, evolution, fluid dynamic modelling
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