> language? In the latter "probably" just means "likely to happen" but > if EVERYTHING happens then how can the concept make sense? I guess it > must be two different concepts, then?
No, not necessarily. There are two ways that probability can play a "real" role in MW. This is no different from how it plays a role in other interpretations of quantum physics, though. First would be real-world probability. Take an electron cloud. We can say that the probability that the electron appears in a certain range is, say, 90%. This is a real probability that guides our expectation. If we measure a bunch of electrons we expect to find around 90% of them in that range, and when we measure them, we do. In MW this is like saying that 90% of worlds consist of that particular electron being in that range. There are an infinite number of places that electron could be, and an infinite number of places it could not be. But there's still a 90% chance of it being in the specified range. So we can...in a sense...think of 90% of the possible worlds being in that range. If you're confused it's probably in part because of a lack of understanding in the shift from finite to infinite. Infinite numbers don't operate under the same rules than finite numbers do, just like negative numbers operate differently than positive numbers. I could explain this but it would take a few hours of expounding on set theory to get you there. Just know that infinite sets are compressible and manipulable in ways that finite sets aren't. For example, we can pair up the squares of all natural numbers with the set of all natural numbers one-to-one: 0 = 0, 1 = 1, 2 = 4, 3 = 9... and so on, so that no number in either set is unpaired. This is possible even though the odds of selecting a perfect square arbitrarily out of the natural numbers is 0%, because as you approach infinity, 0% of all natural numbers are squares. Newton took this to mean than reasoning about infinity was absurd, but this was because he didn't understand the difference between the cardinality and the ordinality of numbers. Second, we can talk about what it means for something to have virtually no chance of happening. We should always expect things that are beyond reason not to happen, even though an infinite number of such worlds must exist. A cow could appear directly in front of me right now due to quantum effects, but the odds are virtually zero so I do not expect the occurrence. In these cases a mathematician would say that "almost all" worlds obey a certain property that precludes the appearance of the cow. "Almost all" has a technical meaning in mathematics, but it means that the chance of something occurring is too minute to put in terms of a real number. > Another thing I wonder about: Are your understandings of MW purely > mathematical, or can you imagine or "see" the MW universe before your > eyes? In particular: Can you "see" the probability aspect of it? And > in that case, can you describe it in a simplified way for a dummy like > me? I can envision it somewhat, but it's an abstract idea, yes. Just think about an electron cloud, for one example. It's a cloud of probability...but the electron isn't totally bound by it. It's just less and less likely to be further and further away from the main portion of the distribution. Anna --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---