Consider the 2 Slit Experiment:
An example of this is the “2 Slit Experiment. If we let a stream of quanta pass through a barrier with 2 slits then hit a screen they form an interference pattern of light and dark bands (Absolute proof that what we are looking at are waves.) BUT, when we use the photoelectric effect to detect the quanta hitting the screen, we get discrete packets of energy (Absolute proof that what we are looking at are particles). Then it gets really strange. If we put a detector next to either slit so that we know which slit a given quantum went through, but leave both slits open, the pattern disappears. If we know which slit the quantum went through, we get one behavior (no pattern). If we do not know, we get a different behavior (pattern). We must somehow explain how a particle orders of magnitude smaller than the distance between the slits somehow passes through both slits and interferes with itself.
Somehow, and no one knows how, observation changes the behavior of photons. Early quantum mechanics theorists were uncomfortable with Wave-Particle Duality. They felt that a photon was always a quantum, never a wave. So, how to explain the change of behavior with observation? Neils Bohr and others came up with the Copenhagen Interpretation ===> Nothing exists until it is observed. Bohr debated this issue with Albert Einstein in the Einstein-Bohr Debates.
Einstein took the position that the moon existed even when no one was looking at it.
Bohr countered with: How do you know? What proof of existence can you offer WITHOUT observation?
The idea here is: The behavior of quanta is solely dependent on observation by a conscious observer.
Don't feel bad.
You are trying to make sense of something that does not make sense.
“By 1928 or so, many of the mathematical formulas and rules of quantum mechanics had been put in place and, ever since, it has been used to make the most precise and successful numerical predictions in the history of science. But in a real sense those who use QM find themselves following rules and formulas laid down by the ‘Founding Fathers’ of the theory…. Without really understanding why the procedures work or what they really mean. ….
What are we to make of all this? Does it mean that on a microscopic level the universe operated in ways so obscure and unfamiliar that the human mind, evolved over eons with phenomena on familiar everyday scales, is unable to fully grasp what really goes on? Or, might it mean that through historical accident physicists have constructed an extremely awkward formulation of QM that, although quantitatively successful, obfuscates the true nature of reality? No one knows.” – Brian Greene, The Elegant Universe
'I think it is safe to say that no one understands quantum mechanics'. Richard Feynman
If anyone understood QM it would have been Richard Feynman
Who needs fantasy, when they have Quantum Mechanics - Me
I find the best way to approach QM is: QM is like going to see a fantasy movie (Harry Potter, Twilight, Lord of the Rings, Underworld, etc). Though the movie involves a universe that has different rules from the universe we live in, we have no problem accepting witches, warlocks, hobbits, werewolves, vampires. We learn the rules and the movie makes perfect sense. (Quick: If you saw a person that sparkles in sunlight what is he or she? I bet you could answer without thinking about it. Though you know that people do not sparkle in sunlight. You know the rule, accept the rule, and apply the rule.) The thing about QM is, QM is real. The rules describe the sub-atomic world accurately. The rules are consistent and rational, BUT they are also illogical and counter intuitive. We must accept (like the movie) that the rules make sense in that world, even though that make no sense in the macro world of things larger than an atom.
http://en.wikipedia.org/wiki/Interpretation_of_quantum_mechanics
We do not “understand” QM, we “Interpret” it. We form mental pictures of what is going on and they are weird because QM is weird. The Interpretations may not be “reality.” Copenhagen is just one of those Interpretations. There are over 20 Interpretations and all of them work equally well to describe quantum behavior.