Heisenberg's Uncertainty Principle is fundamental in Quantum Mechanics. The spread in wavelength corresponds to the spread in momentum. Our theoretical calculation shows, precisely determines a particle's position is, so less precise is its momentum. Planck’s mass mp is the mass after which the quantum effects of gravity become significant. In this paper, we have presented a new heuristic view of Planck's units. By using Planck’s units, we will redefine the validity of the Heisenberg Uncertainty Principle. Relationship between Planck's Length, Planck's Time and Planck's Mass results in the origin of the Heisenberg Uncertainty Principle. The laws of Quantum Mechanics and Quantum Field theory permits us to quantise the energy of photons. We will raise the conjecture (the purport of which will be called the theory of Quantisation of Space and Time) that Space and Time are physical entities having Space Quanta –Spacion and Time Quanta –Timion. Time and Space itself is a physical entity which have the lowest limits. The fabric of space-time is a 4-dimensional Tesseract, where 3 dimensions of Space are fixed and 4th Dimension, time is constantly projecting the universe in the forward direction. Space-Time is constantly evolving, the Time quanta and Space quanta are the building blocks of empty space.