From Restraint Relativity it is possible to consider a corpuscle as a packet of strings. The variation of the length of this packet is equal to the phase speed of the corpuscle as a packet of waves times an universal constant. In a system of units where ℏ=c=a=1 the string vector becomes equal to the wave vector. With this notion of packet of strings the principle of uncertainty is incorporated in Relativity & Classic Mechanics.Vacuum energy density problem is resolved and we had concluded that Newton gravitational constant depends on the observable radius of the Universe.At the vicinity of the horizon of a black hole the spectrum of radiation in the visible range will be continuous.With the notion of modular cells General Relativity equations can be resolved easy by machine calculator. There is great similitude of equations forms of modular cells for weak & strong gravitational fields.We had propose also a new model for the hydrogen atom and associate to a black hole a Planck atom by similitude to Bohr atom.