?Anyone who is not shocked by the quantum theory has not understood it? - Niels Bohr.
It has been nearly a century since Max Planck proposed that electromagnetic radiation comes in tidy bundles of energy called quanta. Building on this seemingly fragile supposition, scientists erected what is by far the most successful theory in the history. In addition to yielding theories for all the fundamental forces of nature (except gravity), quantum mechanics has accounted for such disparate phenomena as the shining of stars and the order of the periodic table. From it have sprung technologies ranging from nuclear reactors to lasers.
Quantum mechanics is a theory which tries to describe, and predict the behavior of physical systems. The theory was originally designed to make predictions about the behavior of sub-microscopic systems, like atoms and electrons, but since even large-scale systems are composed of atoms, quantum mechanics necessarily comprises a fundamental physical theory--a theory which attempts (at least in principle) to offer as complete an account as can be had of the nature and behavior of physical systems. Herein I try to briefly investigate what are the presumptions of an essentially scientific theory and how does the Quantum Theory fit into them and what are the glitches therein.
Science implies knowledge collected by following certain rules, and presented in a certain way. Scientists believe in the existence of an external reality. Scientists therefore look for external proof; they study those aspects of knowledge where there can be serious agreement. And that knowledge they group under laws, which are invariable relations and regularities. A law is an invariable relationship universally accepted in the relevant scientific community. A scientific theory is more open to doubt and refutation as against hypothesis which is tentative. .
Laws do not provide explanations; they simple state the relationship between the relevant variables.