From: Robert Acres 23/06/99 16:26:43 Subject: Quantum Reality post id: 19274 Greetings, I understand that time is relative and that at differing speeds time will pass at different rates. it is relative to the observer. That is simple relativity. What i am wondering about is the effect this would theoretically have on parralel quantum realities, i.e the diverging realities that exist for every possible situation from every instant of time. If time passes at a different rate, relative to the observer, how does this effect the creation of parralel universes. One possible answer that i have devised is that there is a 'psuedo absolute time' that exists for a vaccum and that the parralel realities are relative to this time. Can you please help? Thanks, Robert Acres Acres@senet.com.au From: phoebe 23/06/99 16:53:00 Subject: re: Quantum Reality post id: 19296 it sounds really fun but i do believe i've read it in Red Dwarf. As it is that theory is far too intelligent for me to understand, but from what i got, yes, it's possible. Have you considered writing science fiction? happiness to you all phoebe From: Chris (Avatar) 23/06/99 16:58:12 Subject: re: Quantum Reality post id: 19299 Simple answer: There is NO absolute time, pseudo or otherwise, associated with vacuums or anything else. The divergent universe or parallel world interpretation of quantum mechanics is just that - an interpretation. It is not meant to be taken too literally. Relativistic effects such as time dilation, length contraction, etc occur in the quantum world as well as the macroscopic world. Hope this helps! Chris From: Robert Acres 23/06/99 17:31:08 Subject: re: Quantum Reality post id: 19325 The duality of time dilation at the macro and quantum level is the root of my query, i am just interested to see if there would be any phenomenon related to objects at the macro level and the parralel realities that their respective positions create, i.e, is there a sync issue associated with each object, etc From: Robert Acres 23/06/99 17:33:00 Subject: re: Quantum Reality post id: 19326 i know that there is no absolute time, i was just making a frame of refrence, probably did not phrase it properly. thanks anyway From: Shanon 23/06/99 20:50:12 Subject: re: Quantum Reality post id: 19391 I haven't delved to deeply into quantum mechanics, or general quantum theory, so this may sound stupid. Isn't time relative to the observer when it comes to parallel realities in the multiverse - such that we can only appreciate a quantum event or quantum reality 'now'? In fact, as we look at discrete quantum realites, are we not forced to accept that time is quantised? Also 'the diverging realities that exist for every possible situation from every instant of time' seems to be infering that there is a time continuum from which diverging realities spring. Terribly sorry to be so reflective, as I said, I haven't delved to deeply into things quantum science. From: Brett Hall 24/06/99 3:04:30 Subject: re: Quantum Reality post id: 19456 "The divergent universe or parallel world interpretation of quantum mechanics is just that - an interpretation. It is not meant to be taken too literally." If we are talking about the "multiverse" theory - which is *the* explanation of Quantum Mechanics then I am rather perplexed by the label Chris has given it as being "just...an interpretation". It *is* meant to be taken literally. Let's take (very briefly) the example of the twin slit experiment. Photons are fired at the slits ONE AT A TIME. An interference pattern is produced. Why? Now you can come up with all sorts of wierd and wonderful "conjectures" but only one explanation has stood the test of time. That is that there exist parallel universes (but this term is misleading) - the term used by cosmologists and those in the field is the word "multiverse". I order to get the pattern observed on the screen the only explanation is that other photons are interferring with the photons we see. Those photons exist in another parallel universe. Saying that multiverse theory is just an interpretation of Quantum Mechanics is like saying that the heliocentric theory is just an interpretation of Newton's laws. It's much more than that! No doubt this will cause debate. From: Dr. Ed G (Avatar) 24/06/99 3:54:07 Subject: re: Quantum Reality post id: 19457 No, you don't need to accept the multiple universe interpretation as ontological reality... you just need to accept that describing photons as classical particles cannot give you the right answer. While you might need to introduce multiple Universes in order to preserve some classical particle analogy for photons, you don't a priori really NEED it to describe their behaviour... certainly I haven't seen any convincing evidence to choose between the many possible explanations for the ontological significance of the Copenhagen Interpretation of Quantum mechnics - which only itself talks about what properties can simultaneously be said to EXIST for any given system - i.e. that there is no physical reality beyond the limits of Heisenberg Uncertainty. Indeed I believe Huw Price at the University of Sydney has written a whole book (something about Archimedies arrow) proposing an interpretation that resolves this supposed uncertainty so long as you let particles, in a very real way (not in the way Feynman proposed in order to simplify the maths), move backwards in time. This solves problems about local reality... but then throws any ideas you might have about causation into chaos (Personally, I'm happier to live without local existent reality than I am to live without causality). Soupie twist, Ed G. From: Chris (Avatar) 24/06/99 12:12:47 Subject: re: Quantum Reality post id: 19581 Well, Eds beat me to it. I don't think I could have put it much better, other than to add that the many universe interpretation appears to be a whole lot of interpretive baggage to invoke in order to maintain an essentially classical view of quantum particles. It does, however, have some uses - eg it explains parallel electron processing in quantum computing pretty well (for me anyhow). But as Eds says, the reality remains regardless of the "story" we invent to try to make it sensible in our classically-geared heads. Chris From: James Richmond (Avatar) 24/06/99 21:24:14 Subject: re: Quantum Reality post id: 19823 Contrary to popular opinion, things like electrons and photons and quarks are not particles. They aren't waves either. They are quantum things which happen to possess the peculiar features we describe by the term "wave-particle duality". Under certain conditions they behave like classical particles; in other circumstances they behave like waves. The key word in the previous sentence is "like". Quantum-level objects are like particles and waves, but are in themselves a separate type of entity. The behaviour of electrons in a double-slit experiment, for example, is described very well by the mathematics of quantum mechanics, which describes the electrons using a quantum wavefunction. Quantum mechanics allows us to predict with great accuracy the probability that any particular electron will land in a certain spot on the screen. However, the theory cannot predict exactly where any particular electron will land - it only tells us about the probability distribution of the wavefunction. In order for an electron to be actually seen at a particular place on the screen, the wavefunction must somehow "collapse" so that all the possibilities resolve themselves into a single outcome, whose probability is predicted by the wavefunction. Exactly how the "collapse" of the wavefunction occurs (i.e. by what mechanism) is not explained by quantum mechanics. It is this part of the theory which is contentious. The "multiverse" theory is one of many possible mechanisms proposed to explain "collapse of the wavefunction". This theory says that all possible outcomes always occur, each one in a separate universe. We see one outcome because we are restricted to one universe. Another theory suggests that the "collapse" happens when an "observation" is made of a quantum system. No multiverse is necessary in this theory, which is probably more popular than the "multiverse" theory. However, there is still much argument as to what constitutes an "observation" and what is a qualified "observer". There are other, more speculative theories. Roger Penrose, for example, thinks that collapse may have something to do with gravity and the structure of spacetime at the quantum level. To sum up, the multiverse theory is by no means a necessary part of quantum theory. We can use quantum mechanics quite successfully without ever worrying about the question that the multiverse theory attempts to explain. On the other hand, explaining "collapse of the wavefunction" may eventually turn out to be quite important in advancing our knowledge of nature. As an explanatory mechanism, the multiverse theory is rather messy, since it requires the spawning of an infinity of universes every tiny fraction of a second. It also has the disadvantage of being untestable at present, although this may not always be the case. Personally, I don't like the theory, mainly for asthetic reasons, though of course this has absolutely no bearing on whether it is correct or not. JR This forum is un-moderated. The views and opinions expressed are those of the individual poster and not the ABC. The ABC reserves the right to remove offensive or inappropriate messages.