The Heisenberg Uncertainty Principle states that no particle can be completely motionless (since it is not possible to know two complementary parameters of e a particle at the same time), it will at least oscillate around a plane: in this case we will talk about Zero Point Motion. From Quantum Mechanics we learn that a real particle will never have a null energy, but it will always have a minimum possible energy called Zero Point Energy. We also learn from Quantum Mechanics that Absolute Zero temperature can never be reached. At this temperature, in fact, the motion would cease and we would be able to know simultaneously the two complementary parameters we mentioned before: the position and the momentum of the same particle. In a number of cases, in fact, extremely low temperature have been reached, but never touching 273, 15 degrees Celsius. Thus we will talk about Zero Point Temperature. Relativity's Theory, on its turn, tells us that mass and energy are equivalent. Einstein, in fact, realized that scientists were wrong keeping about the mass and E as two phenomena which though linked, were basically different. On the contrary, he understood that they had exactly equal behaviours: both expanded and contracted according to an identical factor. Under every significant aspect, Einstein concluded mass and E were entities indistinguishable and interchangeable, and formulated his famous formula: E = mc(2). So any particle having energy should carry a mass, though tiny, corresponding to the energy of the examined particle divided the square of the speed of light.