In a recent article entitled “Is gravity the force driving time forwards”, a new theory is proposed in order to explain why time evolves only in one direction. The theory attempts to complement the Second Law of Thermodynamics, which has been instrumental in terms of establishing the concept of arrow of time based on entropy.
The article suggests that while entropy explains why a shattered cup won’t spontaneously recompose itself into its original form, it doesn’t explain why the cup exists in the first place. This is due, according to the authors, to the clumping power of gravity. It is them claimed that:
‘Overall, it’s no surprise to learn that the Universe gets more complex with time.’
This statement is not entirely correct. In our earlier article “The Fourth Law” we show how in the presence of non-decreasing entropy, complexity does indeed grow but then it peaks at a certain time. This is illustrated in the plot below.
It also suggests that as entropy will erode all structure in the Universe – complexity is zero – there may be a Big Crunch.
The evolution of the post-Big Bang Universe is proven by the fact that we observe increasingly complex structures, planets, stars, pulsars, quasars, galaxies or clusters of galaxies. However, we don’t know where are on the above complexity curve today. Time will show!
Complexity is the bridge which connects structure (S) and entropy (E). Complexity brings together the two strongest and antagonistic forces of Nature – the urge to create structure and the compulsion to destroy it. C=f(S; E).