Neo-Newtonian Cosmology vs Big Bang

                                      Big Bang of Ylem into Inflation. 

Big Bang is a cosmological theory suggesting that the Universe originates from a very hot very dense initial state of very small size (named "Ylem"), which through a period of very strong inflation expanded into a very large void sparsely filled with a fine cosmic web of galaxies.  

Big Bang can be dismissed with reference to Leibniz' Principle of Sufficient Reason since no clue is given to the formation of the very hot very dense very small size initial state. Big Bang describes a scenario for creation of Something Big (the Universe) from Something Big (hot dense initial state), while the real problem concerns creation of Something Big from Nothing or more reasonably: 

• Something Big from Something Small.  

Neo-Newtonian Cosmology NNC offers an alternative to Big Bang of this form. Here the initial state is a zero gravitational potential $\Phi =0$ satisfying the differential equation $\Delta\Phi =0$ with $\Delta$ the Laplacian differential operator in an infinite Euclidean coordinate space. 

From this zero initial state the Universe is then created from a small scale small amplitude large size perturbation $\phi$ of $\Phi$ with $\rho\equiv\Delta\phi$ appearing as a small scale large amplitude large size mass distribution of variable sign, which through segregation of positive and negative mass driven by gravitational force $\nabla\phi$ develops large regions with either positive or negative mass, which repel each other. Here the step from Small to Big is performed by the Laplacian differential operator acting on small spatial scales $h$ with multiplicative factor $h^{-2}$. 

NNC does not start from Nothing since an infinite empty Euclidean space capable of expressing Laplace equation $\Delta\Phi =0$ with a zero gravitational potential $\Phi =0$, is taken as given, but this is far less than the Ylem + Inflation of Big Bang. In NNC the Universe emerges from a small perturbation $\phi$ of $\Phi$ as Something Small through the action of the Laplacian and gravitational force as understood physics. 

The main support to Big Bang comes from an observed apparent expansion of the visible Universe from increasing redshift of far way galaxies, which when reversed in time gives a contracting Universe possibly leading back to an Ylem. But reversing time to recreate history may be impossible in the same sense as recreating a sharp image from a very blurred one. 

The Big Bang theory was first proposed by the catholic priest and mathematician Lemaître almost 100 years ago. It is strange that nothing more credible has been produced by modern physicists.

It was further developed by Alan Guth in 1980s as inflation theory suggesting an increase of the size of Ylem by a factor of $10^{26}$ in only a small fraction of a second. Only a modern physicist could come up with something like that... 

Summary:

• NNC describes creation by known physics of the Universe from a small perturbation in an Euclidean space with Laplacian. 
• Big Bang requires Ylem + Inflation both without known physics.