----- Original Message ----- From: "Robert Seeberger" <[EMAIL PROTECTED]> To: "Killer Bs Discussion" <[EMAIL PROTECTED]> Sent: Wednesday, July 30, 2003 5:59 PM Subject: Re: TI interpreation of QM
> > The example that I find offensive goes something like this: > Locations A, B, and C are seperated by great distances. C is much closer to > B than it is to A. At C, there is an observer watching events at both A and > B. At A, an FTL ship leaves heading for B. Observer at C sees the ship > arrive at B, and only later sees it leave A. > This is supposed to be a violation of causality. That's not the problem. If two points are spacelike, then there will be a reference frame in which they are simultaneous, many reference frames in which A is before B, and many reference frames in which B is before A. With FTL signals , one can send a signal from from A to B to C, and find that C is timelike with respect to A, and is before A. In other words, a transmitter can send a FTL signal to a receiver/transmitter pair, which sends another FTL signal to a receiver attached to explosives surrounding the origional transmitter. This allows the transmitter to be blown up via a signal that was sent after it was blown up...but since it was blown up, the signal wasn't sent, so the transmitter was blown up, so the signal wasn't sent...etc. > I don't see how it could be. Its just an optical illusion since events for > the ship follow the normal linear progress of time (exempting local > relativistic effects). You have to remember that all reference frames are equally valid in SR. A spaceship traveling at .99c with respect to the earth would see time slow on the earth; as we would see time slow on the spaceship. > So when I see causality being invoked, I look for an opportunity to find > real reasons why causality must necessarily be preserved. I hope my example helped. There is another way that involves rotations with analytical geometry. Put all space axis where the x axis usually goes, and time where the y axis usually goes. Changes in velocity are represented by a rotation in coordinate systems. So, time > > > > > I understand the principle that states that cause cannot precede effect. > > > *That* is quite easy to understand. > > > And I seem to recall that there is some axiom that says there are no > > > privileged frames or points of view. > > > > > > But couldn't it be that "backwards in time signals" are part of an > > > underlying backbone or framework that underlies reality, normally > > > unobservable? > > > > It could. But, the problem with that is, if you allow real, > unobservables, > > with no addition to the predictive power of the theory, then you open > > things way up. > > Is that necessarily a bad thing? Yes. One could have a zillion models, and no way to distinguish between them. >Has it never occured in the past as part of > a workable theory? No. Workable new theories have different preditions for experiments than the older theories. > Just a history question mind you! <G> > > As I said before, with that sort of latitude one could > > resurrect the aether. Indeed, with that type of latitude, I could > generate > > a geocentric universe. > > > > That would falsify the theory wouldn't it? Not really. Its straightforward to have a coordinate system that rotates with the earth. One would just have to look at the terms that came from the traslation from an inertia coordinate system to a rotating coordinate system. Let me give a simple example of this. We know that centrifical force is a fictional force. I could make it a real force, but add complications. Lets assume that a system rotating with the earth were called fixed. A real centrifical force would be defined. When one rotated in one direction it would keep on increasing. When one rotated in the other, the force would decrease to zero, and then start increasing again. Obviously, this is complicated, but if one is allowed to introduce real complications with no additonal predictive value, than one > > > > That makes sense since observation would by itself change the signals. > That sort of reminds me of some things I've read concerning "Anthropic > Principles". Its more complicated than that. Simply assuming that unseen values exist apart from observation, and assuming that the know laws of physics are not secretly violated, one gets the wrong answer. > > > > > And I suppose my proposal is "if the simpler explanations have not > > >worked, perhaps trying a higher level of complexity might". > > > > But, the simpler approach worked. > > So, is TI a dead issue? For the most part. MWI tends to have more support, but I'm not sure how many folks really believe in the infinity of Robs and Dans being created every annosecond. > > Detailed predictions have been verified, > > to many significant figures. So, why add metaphysical baggage? > > Understandable. > > > > > > I really wish I had a greater understanding of QM and how it differs > from > > > relativistic theory. > > > > I can repost some of my several years old discussions of spacelike > > correlations, if there is an interest. > > > > That would be nice. > My knowledge of physics resolves to related and isolated factoids. > There are plenty of fundamentals that I am missing. > I just gather them up as I go. When I have a bit of time, I'll do that. Dan M. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
