excreationist

Those aren't the only options.
Another one is that the multiverse is a static entity where its beginning, alternate middles, and alternate ends(?) exist eternally.
Discover magazine article.
This talks about Julian Barbour's idea - he calls the static entity which describes all of the points in history of the parallel universes "Platonia".
Platonia has a tree type structure and the big bang is just the bottom of the tree where all the matter and energy is at a highly compressed starting point. (Maybe it's pure energy - I haven't read his book) The main thing about his theory is that there is no time - so there is no need to something else to have caused everything.

bd-from-kg

Belem:

The standard (Copenhagen) interpretation says that quantum events are truly, intrinsically random, and that therefore the universe is not deterministic. The many-worlds and transactional interpretations are perfectly viable (i.e., they are consistent with all experimental results to date) and both are strictly deterministic, but each is weird in its own way.

But even in these interpretations a particle does not have a specific position and velocity. The fact that particles can exhibit "interference" effects, as in the famous double-slit experiment, seems to rule that out definitively. And a number of experiments by now seem to show pretty decisively that Bell's inequality is violated (as predicted by QM). Assuming that these results hold up (and there is every reason to think they will), this rules out all locally realistic "hidden variables" theories.

Sorry to have to throw out terms like "locally realistic" and "Bell's inequality" without defining them, but I just don't have time to go into what they mean right now. (Maybe later.)

jpbrooks

I apologize for forgetting about this thread. Here are some websites that may explain some concepts related to this topic. (I have only recently become familiar with these ideas, and my choice of explanatory articles and essays will reflect my level of understanding of QM.)


Bell's Theorem

Quantum Weirdness

Metaphysical Implications-1
Metaphysical Implications-2

I have more, but I have to run.
(I'll try to fix these links later.)

jpbrooks

My editing time has expired, so I'll have to rewrite the post later.

Abrupt

Most people might, but most people are deeply confused about a wide variety of things. The idea that the thesis of determinism has something to do with predictability is one example of a popular confusion.

What determinism means is that if one knows the initial conditions of a physical system and the equation by which the system evolves, one can derive the state of the system at any other time. This "one" referred to in the definition above does not have to be a human physicist, and indeed does not have to be a physically or even logically possible being. It is Laplace's demon, a mythical critter that knows everything there is to know about the state of the universe and has unlimited computing power. More likely than not, there are no Laplacian demons around, nor could there be (in fact, it seems to me that the concept is subtly incoherent). Not that this tells us anything about determinism.

The fact that human scientists cannot in practice predict physical systems with Laplacian accuracy has no bearing on the issue. If I take a simple clock, a perfectly deterministic and predictable system, and throw it in a lake, it will cease to be predictable simply because we no longer have access to it, but it will not cease to be deterministic. Determinism is a thesis about causal relations between the states of physical systems, not about our ability or lack of ability to reliably describe or predict them.

Now the orthodox interpretation of QM gives us a system that is indeterministic not because its states are related just like the clock's states are, and we simply cannot predict them, but because the actual description of the system is inherently probabilistic. This is one interpretation, not the alpha and omega. There are hidden variables theories, like Bohm's, that give a deterministic account of QM, though at the expense of some intuitively appealing notions about causality (Bell has shown that there can be no hidden variables interpretation of QM that is both local and deterministic). There are also Everett-type "many worlds" interpretations, that - IMO - get rid of most of the classical conceptual problems with QM, such as locality, randomness, and the measurement problem, but have a hard time explaning probability and result in ontological consequences that some people find absurd.

Starboy

Abrupt, Welcome to IID!

My original question still applies, which kind of determinism, philosophical (yech) or scientific (yum). I guessed from the tone of OP, the poster meant scientific, in which case it does imply prediction. As for the “many worlds” interpretation, it is as convincing as the Copenhagen interpretation. I’m a positivist, theorize anything you want, if it can’t be observed, who cares. I will only take the interpretations seriously when they can predict results that conflict with one another and can be tested with experiment.

Starboy

Abrupt

Thanks. Cozy place you've got here.

I'm not really sure what a concept of "scientific" as opposed to "philosophical" determinism would look like. Determinism is about causality, not about predictability, and that's that. If determinism was about predictability, then it would be rather trivially false, since we can't make any Laplacian predictions when we're dealing with real systems, not even classical systems which nearly everyone will cheerfully admit are deterministic - like mechanical clocks. In fact, the entire distinction between quantum and classical systems w.r.t determinism amounts to nothing more than asking whether probabilistic descriptions are reducible or not. If you think this question is meaningless (and as good positivist, you should), then you really shouldn't have any opinion about determinism.

The OP, by the way, says: "I would like to know if QM assumes that random events are intrinsically random or they just seem to be random because we cannot determine a particle's position and speed at the same time?" This does not seem like a question that someone of your persuasion would ask.

Starboy

Because philosophers are such slackers, it is sufficient to postulate that event B was caused. This is not allowed scientifically. If you say event B was caused you must demonstrate how it was caused. You must find the event A that causes B. You must be able to reproduce it, and others must be able to reproduce it. You can then make the statement that event A causes event B. When you have done this you have made a prediction. This description of causality would be considered an example of classical determinism. In the quantum case, as an example you would start with event A and it could lead to event B or event C. For any given instance of the experiment it is impossible to predict if it will be event B or C. If one conducts the experiment many times and analyzed it statistically QM would predict the results. So scientifically, causality does imply predictability.

Starboy

jpbrooks

(Please disregard my previous posts.)

[QUOTE]Originally posted by jpbrooks
[B]I apologize for forgetting about this thread. Here are some websites that may explain some concepts related to this topic. (I have only recently become familiar with these ideas, and my choice of explanatory articles and essays will reflect my level of understanding of QM.)

A Lazy Layman's Guide to Quantum Physics

Bell's Theorem-1

Bell's Theorem-2

Quantum Weirdness

Metaphysical Implications-1

Metaphysical Implications-2

(I hope that's not too much introductory reference material.)

Abrupt

Simply asserting a causal relation is not allowed philosophically, either; you have to back up your assertion with some kind of argument. On the other hand, being able to directly verify and reproduce the causal relation is not always required even in science, although it is always desirable. Historians, philologists, evolutionary biologists, and people in many other different fields (hell, even physicists) run into problems with verifying causal relations all the time, because, e.g. the relation occurred at some specific time in the past and is no longer available for us to experiment with. In such cases, strict verification may not be possible at all. You have to make a case for whatever makes the most sense and go with that.

But you weren't even talking about "asserting a (particular) causal relation"; you were talking about asserting that something is caused. This is different. Verifying what causes, say, cancer, or aging, or migraines, or economic recessions may be very much possible, but even if I have not verified the causal relation as of yet, it would be rather strange of me to claim that consequently we do not know whether one exists. We may not know what - exactly - causes aging, but if you go to a gerontologist and tell her that nothing causes aging, you're not likely to get a favourable response.

That said, I still don't understand what you mean by "scientific determinism". Based on the previous post, it seems like in order to take determinism seriously, you would have see every single causal relation in the universe verified and reproduced. As I said before, this is not very reasonable, since it seems to make determinism trivially false (what is "yum" about that?).