The following excerpt was taken from here

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[u:1a9432e703]EPR paradox[/u:1a9432e703]

In quantum mechanics, the EPR paradox is a thought experiment which challenged long-held ideas about the relation between the observed values of physical quantities and the values that can be accounted for by a physical theory. "EPR" stands for Einstein, Podolsky, and Rosen, who introduced the thought experiment in a 1935 paper to argue that quantum mechanics is not a complete physical theory. [/quote:1a9432e703]

My question is, at what point exactly was the deterministic, causal model for reality first threatened? And was it threatened by an actual empirical observation? Who made the observation? What did they observe? And how?

And my second question is in regards to this:

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The EPR paradox is sometimes referred to as the EPRB paradox for [b:1a9432e703]David Bohm[/b:1a9432e703], who converted the original thought experiment into something closer to being experimentally testable.

David Bohm’s first book, Quantum Theory published in 1951, was well-received by Einstein, among others. However, Bohm became dissatisfied with the orthodox approach to quantum theory, which he had written about in that book, and began to develop his own approach (Bohm interpretation) Û he devised a non-local hidden variable deterministic theory whose predictions agree perfectly with the nondeterministic quantum theory. [/quote:1a9432e703]

Ok, so why isn’t Bohm’s theory taken seriously?

The rest of my questions are more mundane and reflect my inexperience in this subject (but a person has to start somewhere)

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During the last century, quantum theory has proved to be a successful theory, which describes the physical reality of the mesoscopic and microscopic world. Up to now, no method is known which contradicts [b:1a9432e703]the predictions made by quantum theory. [/b:1a9432e703] [/quote:1a9432e703]

Can anyone tell me what these predictions were and how they were made?

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Quantum mechanics was developed with the aim to describe atoms and to explain the observed spectral lines in a measurement apparatus. [/quote:1a9432e703]

What are spectral lines? And why do they exist in [i:1a9432e703]a measurement apparatus?[/i:1a9432e703]

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During the development of quantum mechanics the fact that quantum theory allows for an accurate description of reality is obvious from many physical experiments, and has probably never been seriously disputed.

On the other hand, for the interpretation of quantum mechanics, things could not be more different. Since the theory of quantum mechanics has been formulated, the following question arises:

How can we interpret the mathematical formulation of quantum mechanics?

This question leads to a discussion, in which people with different philosophical backgrounds give different answers. [b:1a9432e703]Quantum theory and quantum mechanics do not account for single measurement outcomes in a deterministic way. [/b:1a9432e703] [/quote:1a9432e703]

What is a measurement outcome? When I open my fridge and look inside, the contents in the fridge are as they are displayed to me. Is that an example of a measurement outcome?

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One accepted interpretation of quantum mechanics is the Copenhagen interpretation. The Copenhagen manifest argued that a measurement causes [b:1a9432e703]an instantaneous collapse of the wave function which describes the quantum system[/b:1a9432e703] [/quote:1a9432e703]

Ok, so I’ve heard this term ‘wave function’ kicking around quite a bit. Can anyone give me an explanation of it that makes more sense then the one given here?

[quote:1a9432e703]The system after the collapse is random - pure chaos. [/quote:1a9432e703]

Why? Have they observed this collapse with the naked eye?