🚀 go-pugleaf

Hi  Enlighten_Me,  You told the Russian_Fool:

  Anyway, how old is the world ?  Take that times....say.... a billion.
  Then, relatively the world did just start yesterday 
  in comparison to that number !

  We don't know how long the world will be in existance.

We know that the density of the _Observable_ universe 
first fell below Planck_Density 13.7 billion years ago.

Given today's best theories and technology,
we can't observe anything denser than Planck_Density.

As far back as we have measured it so far, 8+ billion years,
the acceleration in the expansion of spacetime 
has been _Observed_ to be constant.

In today's standard model of cosmology, the Lambda_CDM model,
that constant acceleration is defined as General_Relativity's lambda,
a.k.a. the Cosmological_Constant, a.k.a. dark energy,
a.k.a. the negative energy density of the vacuum.

I posit that that dissipation has _Always_ been constant,
a true property of mass-energy,
...everything dissipates, everything has a half-life.

So while spacetime is always flat at any moment in cosmic-time,
-- with no center of gravity --, 5D spacetime over cosmic-time is 
negatively curved, hyperbolic, like a 2D hyperbola 
or a 3D horn with an infinitely long mouth piece and flang.

While Planck_Density is currently the limit to our observation,
chances are the unobservablte portion has always been infinitely wide,
and it was infinitely dense infinitely long ago in cosmic-time.

Entropy is how dissipated something is, 
similar to heat capacity, in joules per kelvin.
See:  WikiPedia.ORG/wiki/Entropy

So, for example, infinite Density_and_Heat has no entropy and 
perfect Vacuum_and_Coldness has infinite entropy.

The cosmos is going from no entropy to infinite entropy
according to the second law of thermodynamics and 
the observed value of General_Relativity's cosmological _Constant_, lambda.

Density is what's left-over from the notional start of the big bang,
that's where gravity came from, and where it's going.