Quantum mechanics is a mathematical framework to do Physics. On its own quantum mechanics doesn’t tell you what laws a physical system must obey, but it does provide a mathematical and conceptual framework for the development of such laws. It has replaced classical physics as the fundamental theory. Classical mechanics is a good approximation but it is not the accurate description of our world.
Quantum mechanics is applied to the different physical phenomenon. You have quantum electrodynamics, when you apply it to electrodynamics. You have quantum chromodynamics when you apply it to strong interaction. Similarly, you have quantum optics and quantum gravity when you apply it to photons and gravity respectively.
Unlike Newtonian mechanics, Maxwell’s electrodynamics, or Einstein’s theory of relativity, quantum theory did not originate from a single individual, rather it is a collective work of many Physicists. To this day it retains some of the scars of its exhilarating but traumatic Youth.
There is a lack of consensus regarding the fundamental principles of quantum theory and how it should be conceptualized. Competent physicists are capable of applying quantum mechanics, but their interpretations and narratives often diverge. Richard Feynman once humorously remarked, “I think I can safely say that nobody understands Quantum Mechanics.”
Our primary goal is to learn how to do Quantum Mechanics. I believe without a solid grasp of what quantum mechanics does, one can’t do meaningful discussions about its meaning.
Quantum mechanics does not seamlessly extend from previous theories; instead, it represents a sudden and revolutionary departure from classical concepts. Its mode of thinking about the world is profoundly counter-intuitive, serving as a significant departure from conventional thought.
It is important to note that natural intuitions do not readily apply to this subject. Engaging with quantum mechanics necessitates the development of an entirely new cognitive framework, akin to nurturing an uncharted set of mental faculties.
