Define Quantum mechanics?

Answer 1

It's the physics of wave-particle duality, where objects exist in a superposition of states, such as Schrodinger's famed cat existing in both dead and alive states. Conjugate variables such as momentum and position are no longer independent, nor are energy and time, and the observed is always affected by the observer. It is a rejection of the infinite precision and determinism of Newtonian mechanics, a discipline where probability amplitude state functions have a physical reality of their own, non-local instantaneous quantum entanglement occurs, and even virtual particles and quantum information are said to travel backwards in time. And it's one of the most exact sciences ever developed, experimental observations matching predictions by quantum mechanics to a accuracy not matched anywhere else.

Also, action is quantized, which is why quantum mechanics is so-called, but it's too hard to explain what action is and why it's quantized.

Answer 2

Quantum mechanics is the study of various phenomena on an atomic scale that take place in discrete steps rather than as continuous processes. The emission of electrons from a surface illuminated by light was an early phenomenon to which this applies, and Einstein's study of it won him a Nobel Prize.

Answer 3

In simple layman terms, Quantum mechanics is physics at the sub-atomic scale. Quantum physics has within it, different laws than physics at the macro scale (things we see with the naked eye). To get a better grasp of this concept, I highly recommend Brian Greene's "Elegant Universe" book. It explains how Relativity (physics for big things) and quantum mechanics co-exist. Also look up M-Theory at www.wikipedia.org if you really wanna blow your mind.

Answer 4

It is a a modern physical theory (much developed and refined since Neils Bohr's ground-breaking work in 1913) which deals with the structure and behaviour of subatomic particles. It has given rise to philosophical problems of its own (some quantum phenomena seem to require a non-classical logic) and has also been used by both sides in the philosophical dispute between realist and instrumentalist construals of scientific theories.

Answer 5

Quantum mechanics is a fundamental branch of theoretical physics with wide applications in experimental physics that replaces classical mechanics and classical electromagnetism at the atomic and subatomic levels. It is the underlying mathematical framework of many fields of physics and chemistry, including condensed matter physics, atomic physics, molecular physics, computational chemistry, quantum chemistry, particle physics, and nuclear physics. Along with general relativity, quantum mechanics is one of the pillars of modern physics.

Link,
http://en.wikipedia.org/wiki/Quantum

Answer 6

In a nutshell, quantum mechanics is a branch of theoretical physics with wide applications in experimental physics that replaces classical mechanics and classical electromagnetism at the atomic and subatomic levels.

Answer 7

11 dimensional string theory has not produced anything.

It is possible that the 7 dimensions of space that are not perceived are mathematical deception, and therefore string theory is a theory of nothing, as you will find if you read the wikipedia article on string theory all the way to the end.

Answer 8

Short answer: It is the math behind the application of the theories of physics. It provides the process by which particle behavior is explained.

Check out http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/The_Quantum_age_begins.html for a histoy of physics.

Answer 9

quantum mechanincs deals with measurments at the molecular level.