What is the purpose for Quantum Physics?

Answer 1

Quantum Physics came to light because ordinary physics (Newtonian Physics) does not hold true in two situations:

1) when objects move at extremely high speeds (close to the speed of light)
2) When dealing with extremely small objects (particles etc).

It is very strange that we now use two different sets of rules when working with different situations (as described above). The biggest challenge in physics right now, or one of them, is to bring these two sets (Newtonian and Quantum) of rules/laws together with a single Unified Theory.

Answer 2

It explains physical phenomena at the atomic and sub atomic level, were the rules of the theory of relativity don't seem to work.
Strangely enough, when you use quantum physics one anything over the atomic realm you get strange results (like things popping in and out of reality for no apparent reason). Likewise, when you use the theory of relativity at the atomic and sub-atomic level, you get infinite probabilities.

Some scientists are working an unified theory and the most promising so far seems to be the Super-string Theory.

Answer 3

In discovering the photo-electric effect, Einstein determined that when tiny packets of energy (quanta) in the form of photons struck certain surfaces they could cause an electron to eject. This effect could be produced by few or many photons because it required individual packets of energy. We now know that photons can be captured by the electrons orbiting atoms (and molecules) knocking the electrons into higher more energetic orbits or completely out of the atoms. When the electrons return to their rest orbits in one or more steps they produce one or more new photons. The individual photons have different wave lengths and energy depending upon the amount of excess energy given up by the electron each step of the way back to its rest orbit. Quantum physics allows us to study the relationship between energy and wavelengths of photons, to give only one good example.

Answer 4

According my quantum mechanics course 624,It was about the theory try to explain physical phenoenon by tensor analysis.