What is Quantum Mechanics? It has been seen that from a common people to a Physics nerd everyone fancies the term Quantum Mechanics or also known as Quantum Theory and Quantum Physics. It is very difficult to explain Quantum Mechanics in simple words without divulging brain-twisting mathematical equations. Richard Feynman one of the greatest physicist and Noble Prize winner once said I suppose I can confidently assume no one really knows quantum mechanics. Even Niels Bohr one of the greatest scientists of all time said Anyone not surprised by quantum theory didn’t understand it. Knowledge in quantum physics is quite shallow, and even in the scientific world, there is just partial consensus on what the definition in quantum physics is.

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Quantum Mechanics, along with general relativity, is one of the two key pillars of contemporary physics, and the two theories seek to describe nearly everything in the cosmos itself. General relativity gives us a very large picture (space-time and gravity), while quantum theory gives us a very small picture (atoms and their constituents).

Quantum theory is essentially the concept that all objects isolated from their surroundings, but since large bodies are very difficult to distinguish from their physical environment it basically is a theory of the small universe of atoms and subatomic particles. It is particularly valid for those aspects of the theory that depend on the absolute identicality of fundamental particles, identicality that can not be seen in the complex, large-scale structures of everyday life.

Classical physics, the explanation of physics that prevailed before relativity theory and different aspects of quantum mechanics describe many facets of behavior on an ordinary or macroscopic scale. Quantum mechanics depicts facets of behavior on ordinary or macroscopic dimensions but extends this representation to the low meaning atomic and subatomic sizes. Many theories in classical physics can be deduced as a true, large or macroscopic approximation of the scale from quantum mechanics.

Quantum mechanics differs from classical physics in that energy, momentum, angular momentum, and many other variables in a bound system are restricted to discrete values (quantization), phenomena are properties of both particles and waves known as wave-particle duality and there are limitations on how efficiently will the merit of a physical quantity be calculated before its measurement, provided the full spectrum (the uncertainty principle)

What is Antimatter? The Curious Case of Antimatter

#### Relation of General relativity With Quantum Mechanics

While the basic postulates in both Einstein’s theory in general relativity and quantum theory are certainly backed up by robust and replicated scientific proof, even although they do not logically explicitly contradict each other, they have proved exceedingly difficult to combine into one coherent, unified model. For certain fields of particle physics, gravity is insignificant, and convergence of general relativity and quantum mechanics is not a matter of priority in such particular applications. The paucity of a correct theory of quantum gravity, however, is an important issue in modern cosmology and the physicists ‘quest for an elegant “All Theory.” The elimination of the contradictions between the two hypotheses is a major goal of modern physics.

#### Relation of Unified Field Theory With Quantum Mechanics

Although Unified Field Theory still remains a model or hypothesis for a grand scheme of physics, it is not complete without Quantum Mechanics or Quantum Theory. The effort to unify the basic powers by means of quantum mechanics continues. Quantum electrodynamics (or “quantum electromagnetism”), which in comparison with general relativity is the most reliably studied physical theory, has been combined with the weak nuclear force into the electroweak force; research proceeds to merge it with the strong force into the electrostrong force. Current predictions state that these three forces fuse into one single field at around 1014 GeV. In comparison to this “great unification,” it is proposed that gravity may be combined with the other three gauge symmetries that are predicted to exist at about 1019 GeV.

#### Uses and Applications of Quantum Theory

Quantum theory is still largely unknown or difficult to understand so larger uses application of Quantum Theory is in unchartered territory. Still, Quantum Physics has variety of uses in our daily life.

- MRI scans, laser beams, CDs, DVDs,
- solar cells, fiber optics, digital cameras,
- photocopiers, barcode readers,
- fluorescent lights, LED lights, computer screens,
- transistors, semi-conductors, superconductors, spectroscopy.

And for more detail with scientifical and mathematical complexity visit wikipedia.