Lorentz transformation plays a key role in Special Relativity by relating the space- time distance between events being observed in a pair of inertial frames of reference. Depending on the relative velocity of the inertial frames, the magnitude of Lorentz transformation varies between the limits 0 and 1. The upper limit 1 represents a case where the pair of inertial frames of reference are stationary relative to each other. The lower limit 0 represents the other extreme case where the relative velocity of the frames is at the speed of light c. Similar numerical limits, on the other hand, appear in Quantum Mechanics but in the context of the summation of the probability density distribution of a particle over a region of space. The upper limit 1 represents a case where the probability of finding a particle in a region of space is certain. The lower limit, represents the opposite case where the probability of finding a particle in a region of space is not likely. The range of the limits being between 0 and 1 in both theories is not a numerical coincidence. In this paper, a combined theory is introduced which relates the Lorentz transformation of Special Relativity to the wavefunction of Quan- tum Mechanics. The combined theory offers a new insight to the physical reality. For instance, it is found that the inherent quantum uncertainties in the spacetime coordinate of a quantum particle in vacuum constitute a timelike four-vector whose length A is invariant. It is also found that local acceleration, like velocity itself, has an upper limit; such that no physical object can undergo a local acceleration higher than c2/A. The latter, in turn, constrains the mass of the smallest possible black hole - called Unit Black Hole (UBH) - to Ac2/4G and its event horizon diameter to the invariant A. The diameter of the event horizon, the mass and the Hawking temperature of more massive black holes are subsequently quantized starting from those of the UBH.