Further, it is generally known that even the speed of light (c) is a QV-function, as it is the exact quotient between l_P and t_P (c = l_P/t_P). This fact and that the above-mentioned ZPE Density Matter Equivalent (DME) is equal to the quotient between Planck mass and Planck volume, supports the idea that Planck units are real and that they represent effectively existing physical circumstances of QV.

On the other hand, natural constants like Coulomb’s Constant and Newton’s Gravitational Constant are per definition absolutely real too, since they represent space parameters that influence our measurements, respectively by increasing or decreasing natural forces, in this sense, electric force (C > 1 Nm²/C²) and gravity (G < 1 m³kg^-1s^-2).

When Max Planck derived in 1899 his natural units (l_P, t_P, m_P), he used a comparison method, whereby he took G, c, and his own constant (h), and thus assembled them according to the corresponding dimensions.  In this way, he obtained a length, a time, and a mass that are as real as any natural constants, since they are the direct product of these. Even Planck frequency (n_P = t _P ^-1) is a very real value, since it is the assumed cut-off of the QV-radiation spectrum [4] and this frequency was used in [3] to calculate the ZPE DME. In addition, in [1], it was demonstrated that the value of the ZPE DME is exactly the same, whether it is derived from n_P or from m_P, thereby implying that the QV frequency cut-off is effectively n_P and that both values are analogous and real.

Since ZPE is per definition the energy contained in QV, the most outstanding conclusion of the above-mentioned is that both, natural constants and Planck units, are real and provide direct evidence about the properties and composition of QV.

This paper follows the above-mentioned research lines and provides strong evidence that the QV and String Theory can be unified through a common 6-dimensonal space that allows well-known properties like particle non-locality or Bose-Einstein (B-E) condensate material waves.