RealQM: From Macro to Micro

Rational physics is based on an idea of reductionism from complex physics on macro-scales to simple physics on micro-scales. But in modern physics of Quantum Mechanics QM, it is the other way around with the microscopic quantum world based on a Schrödinger Equation SE in $3N$-dimensional configuration space for a system with $N$ electrons of infinite complexity compared to macroscopic physics in 3D.

This means that QM is not rational physics violating reductionism with micro infinitely more complex than macro.

RealQM offers a new SE in terms of classical physics continuum mechanics in 3D thus in the form of rational physics. 

RealQM is now implemented in a code allowing simulation of large molecules like proteins with 1000s of atoms, or clusters of simple molecules allowing atomic simulation of bulk properties of fluids and solids, see previous post.

RealQM is essentially a 3-line code for time-stepping (i) non-overlapping electron densities, (ii) evolution of free boundary between densities and (iii) Poisson equation for potentials, and so allows simulation of 1000 atoms on a $1000^3$ grid thus with 1TB RAM. 

A $1000^3$ grid resolves 3 orders of magnitude.  Macroscopic physics can be described on scales ranging over 3 orders of magnitude on a decimal scale: 

• human body: 1 m to 1 mm.
• local society: 1 km to 1 m
• city: 10 km to 10 m
• country: 1000 km to 1 km
• globe: 10000 km to 10 km 
• Earth-Moon: 300000 km 
• Solar System: $10^8$ km to $10^5$ km 
• Distance to closest star: $10^{11}$
• Milky Way Galaxy: $10^{15}$ km to $10^{12}$

Microscopic physics can be described on a similar 3 order of magnitude scale

• size of living cell 100000 au
• size of protein 100 au 
• size of atom 1 au 
• size of nucleus 0.001 au