my first paper of the semester, written for my conceptual quantum physics class

There are three tenets that form the basis of classical mechanics, which is derived from macroscopic observation. The first is realism, the tenet that systems are independent, that systems exist without and independent of measurement. For example, if you’re a baby and Mommy leaves the room, she doesn’t, as you may assume, disappear forever. This doesn’t mean you should hide your surprise upon her return; she’ll love it.
The second is determinism, which states that if enough is known about a system then accurate and precise predictions can be made about its future as well as the outcomes of any experiments done upon said system. For example, if you are running very fast and happen to encounter a cliff, you will fall at a parabolic trajectory instead of continuing in a straight line. The normal force of the ground and the friction which kept you in motion, both forces in addition to gravity in the beginning of the scenario, were removed by your running off of the cliff’s edge, but gravity remains. Good luck.
The third tenet is that of locality. Despite Rowling’s magical world and Newton’s original theory of gravity, action cannot be done at a distance without an intermediary, and that intermediary cannot exceed the speed of light. Rowling’s magical world in the Harry Potter novels has special human beings waving wands and achieving instantaneous effects, a concept which defies locality. Newton’s original theory of gravity, which he urged people not to believe, stated that gravity’s effects are instantaneous, a nonlocal effect that defies the speed of gravity. Classical mechanics is built on local interactions, hence “Action = Reaction.”
Brilliantly, none of these three tenets hold true in quantum mechanics. Quantum Mechanics, which claims to describe the world more clearly and accurately than the classical variety, defies the seemingly indispensable tenets of realism, determinism and locality.
At the quantum perspective, if you take an object, such as a single elementary particle which is massive at rest, such as a proton, and isolate it entirely from all outside influences, leaving it completely alone and don’t look at it in any way, then the existence of that proton is undefined. It doesn’t stop there; if you cordon off a section of the universe and set its boundaries in an arbitrary fashion and put said proton within these boundaries and proceed to not look for that proton, the location of the proton within that cordoned-off area is undefined, along with its very existence. On top of that, other particles may suddenly appear next to our happy little proton and disappear before we look again. Quantum mechanics, specifically through the aforementioned paradox, known as the Heisenberg Uncertainty Principle, defies realism in this fashion.
This Uncertainty Principle has another application that helps with the understanding of the structure of the Atom, which is not, as Bohr originally suggested, analogous to a solar system. The valence spheres in which electrons exist are essentially nonrealist, in that each of them contains either two or eight electrons, but we don’t know where they are or what they’re doing aside from the fact that they must be in these zones. They might be happily orbiting, or they might all be rushed to one side or any other or any configuration in between; we can’t know. The best way to represent this uncertainty is to state that all the electrons in any given valence shell are in, simultaneously, all available space and none of the available space. I, myself, find this more fascinating as demonstrative nonrealism than a fictional cat in a box.
Let’s say, for instance, that you have in your possession a lump of Carbon-14, in the form of an unimaginatively valuable diamond, and an impossibly long life. Over the course of the next 6000 years, about half of that Carbon-14 will decay into Nitrogen-14, a gas, and your C-14 diamond will get lighter, seeming to slowly evaporate as you carry it around. On the Quantum level, it’s much weirder than that. Each and every one of those C-14 atoms, over the next 5730 years, has a 1 in 2 chance of decaying into N-14. There is no rule saying that any one atom is or is not going to decay over this time period; it’s simply a matter of chance. This flies in the face of classical determinism.
A deterministic theory would state that there must be some underlying logic to which Carbon atoms decay, but this assumption would be wrong. There is an underlying uncertainty in the universe, and even knowing everything about a system doesn’t tell you what it will do in the future. This is not to say that anything can happen; some things are more likely to happen than others. The reality is that the probabilistic nature of the quantum world balances out to the seemingly deterministic world we see around us to the point where we can accurately predict the macroscopic world, provided we have omniscience. However, experiments on the microscopic scale can only be predicted to the probabilities of several possible results.
The third aspect of classical mechanics that is utterly defied by the reality of quantum mechanics is that of locality. Let’s say that a stranger walking down the street isn’t looking where he’s going and his shoulder bumps yours. The impact of his shoulder exerts a force upon your own shoulder and your momentum is momentarily changed. This is a local interaction. Now, let’s say you’re the vengeful type and you take out your trusty green laser and call to him, telling him to come back and then shine it into his eyes. The laser interacts locally, though indirectly, as it creates a beam of concentrated photons moving at the speed of light from your pointer to his retinas. The photons act as a messenger between the pointer and his soon-to-be-blinded eyes. Since this messenger doesn’t exceed the speed of light, the whole interaction is local. Where quantum mechanics defers from this is that sometimes, at the very basic level, there are instantaneous interactions.
This is tantamount to saying that our universe of local interactions is governed by nonlocal interactions. If none of the other ideas of quantum mechanics are weird, then this one certainly is. It allows such things as instantaneous electron valence jumping, instantaneous proton interaction over long distances and more. However, it seems that this may have no practical application other than being part of the foundation for all mechanics. Because of the nondeterministic nature of quantum mechanics, a nonlocal interaction can’t be predicted in its effects, period. If such a thing were possible, it would allow instantaneous communication. However, this science fiction probably will never come to reality, because we can’t control randomness, only observe it.
In governing the existence that we perceive, the tiny world of quantum mechanics defies all of our common perceptions. The very tip of the iceberg was covered here; this simply serves as a primer to put one in the right mindset to understand such a bizarre world. Locality, realism and determinism have no place in this world, though they’re convenient. The most accurate and precise definitions of real systems are neither accurate nor precise.