I've been wondering about reality of the quantum numbers: n, l, ml and ms. We know that they are variables discovered by Balmer, Bohr, Stoner and Pauli respectively and if you plug them in the certain formula the results will match with the atomic spectrum. Well, the spectrum is certainly is the real thing, but what about those numbers. We also know that those numbers follow certain set of rules like: n can not be equal to 0, l<n, ml=-l, ..., 0, ..., +l, ms= -1/2, +1/2. We know that each chemical element has specific set of the quantum numbers, thanks to Pauli. That means that we need four such numbers to define the element. We also know that quantum number l defines orbitals s, p, d and f and, therefore, the regions of the Periodic table. However, the Periodic table in its present format does not completely and clearly reflect quantum numbers n, ml and ms. When I re-arranged the Periodic Table, so it strictly follows those four numbers, strange things started to occur. The perimeters of the s, p, d and f blocks became equal ! It became symmetric with the point of symmetry located right in the middle of the precious metals ! I called it ADOMAH PT, or it also is called The Perfect Periodic Table. Then I have deduced that it naturally folds into the regular tetrahedron and significance of the quantum numbers in geometric terms have become apparent. But what does it all mean? Most text books compare the quantum numbers with the wave harmonics, etc. It is all true, but what about the Madelung or n+l rule which is central to the aufbauprinzip suggested by Bohr, as well as to the process of ionization, which follows the opposite order. As far as I know, no one knows, except that ADOMAH Tetrahedron PT provides nice explanation. So, are quantum numbers real? Do they physically exist? What are they?