quantum mechanics: Kastner\'s brilliant blog (Introduction)

by dhw, Friday, July 19, 2013, 16:01 (4146 days ago) @ rekastner

rek: Indeed, people have had long debates about knowledge, and these continue. I'm just pointing out, in view of these debates, that one can't assume 'out of the starting gate' that there is no way to gain knowledge about entities beyond spacetime.-It may well be that we're talking at cross purposes here, which is why I've tried to pin down a definition of knowledge. "Gaining knowledge about" an entity = gathering information, and is not the same as knowing the entity. You objected to my statement: "even if there are objective realities outside spacetime, we cannot know what they are." My point is virtually the same as the one Tony (balance_maintained) has articulated so clearly in his post to you:
 
TONY: As is so often the case, we find precisely what we seek based on the preconceived notions of what we want. I am no exception to that rule, even though I do try to take a more balanced approach. (I just happen to be on the more religious side of the pendulum swing at the moment). If you search for God in science, you will find him/her/it everywhere you look. If you search for proof that God does not exist, you will find it everywhere you look. In either case, the most realistic answer is that what you have found is neither proof for nor against anything, but rather your interpretation of the evidence.[My bold]-Of course we can "gain knowledge", as you put it, and we can draw subjective conclusions from that knowledge, but although there has to be an objective reality, we cannot "know" what it is. All we have is a subjective interpretation. This is obvious from the debates that rage about every facet of the issues we deal with on this forum.
 
Thank you for explaining "transactions". I shall probably make a fool of myself now, because I'm out of my depth and cannot speak your language. However, since you are writing a "popular" book for the layman, I'll just hope that my floundering will be of some use to you! You wrote:-"In general, there are many absorbers for one emitted OW and each responds with a CW corresonding to the capabilities of the absorber. This process sets up a set of possible transactions, which are the interactions of OW and CW between the emitter and each absorber. Only one of these can be actualized, and when that happens, a quantum of real, positive energy is transferred from the emitter to the absorber in a spacetime process."-Would it be wrong to compare this to a literary text that has many readers, each of whom has his own interpretation, depending on his "capabilities"? Each interpretation is an individual "actualization". Again I would argue that the "real" meaning can never be known. The author can tell you what he intended (though authors do not always say what they mean to say), but of course with your unobservable objects there is not even anyone to consult.-Following this analogy, I can understand it if you say the potential meanings are within the text, and in that sense are "real". But once we take the line that non-actualized potentials are real, ANY actualization can be viewed as a pointer to other realities. We can argue that although I am the spacetime me, and I live in a spacetime universe, other potential dhws and universes are also real. How can we demonstrate that they are or are not? I'm not arguing that the only reality is spacetime reality, but I'm struggling with the idea that we can ever "know" realities beyond spacetime. We can speculate, and even believe, but although we can gather information, we have no access to the objective truth underlying that information. You have said that QM is a "theory of objects that cannot be observed." As I said earlier, and in conjunction with Tony's comments, it seems to be a licence for people to believe whatever they want to believe. But I may have misunderstood the whole argument, or perhaps your lectures on science and religion will make it clearer. Again I can only plead for patience!