Silent Acorns

A theist could easily say that the "preferred" frame is whatever frame God is in, couldn't they?

Clutch

A lovely discussion, not of gods, but of Aristotle, logical fatalism, and lots of other exciting things, is found in Paul Horwich's very accessible Asymmetries in Time. Buy one for you and one for grandma.

sandlewood

bd-from-kg, very nice and well-thought-out comments.
Before I say anything, I have to confess that I have not read much on this topic. But it seems to me the opposite is true. I tend to think that there is only now. Time does not exist, only change. This has been said by others in this forum I think.

Say that there two friends on earth and one of them jumps in a space ship and starts to travel near the speed of light (to the planet Remulak, where coincidentally women there also take a long time to get ready). When he comes back he may have aged less than his friend did, but for both of them it is still “now”. They both agree it is “now”. It’s just that the friend traveling faster was changing slower. The molecules and subatomic particles in his body changed slower, and his clock changed slower. I have no idea if this is consistent with actual physics theory. It just seems to make sense to me.

I believe this is what similar to what Kenny is referring to here (correct me if I’m wrong):
Could relativity be describing the rate at which things change, things such as clocks and every other physical thing in space? It would make sense to me. Although I realize you are not quite saying this; you're saying that relativity has only told us what the measurements will come out to be, not necessarily why they are so.

Anyway, hoping to stay on topic, I need to tie this in. Personally, I believe determinism is true. Also, there is only “now”, but there is a future in the conceptual sense. If there is a God, then being omniscient he can know the future because it is determined. So this leaves the problem of there being no free will, which religions are based on. (And not to mention the issue of God’s own free will.) Being an atheist, I’m glad I don’t have to worry about such problems.
Forgive me if I don’t correctly understand this. Does the measurement of A actually cause B to be -1? Or is it merely that you deduce that B must have been -1 since you know A is +1?

Philosoft

Out of print. Got one to sell?

Clutch

Well, bugger.

Amazon lists a couple used sources, but I was surprised at the cost, given that (I think) they were paperback. eg, $30+.

Library?

Kenny

I agree that Aristotle’s “Problem of Tomorrow” argument is fallacious, but still wonder if it could be meaningfully held that certain propositions about the future are neither true nor false because the state of affairs to which these propositions refer to do not yet exist.

Well, I agree, which is why I am very much opposed to theological systems which deny that God has foreknowledge. Unfortunately (from my vantage point) such views are quite popular today, even among very conservative evangelical Christians. It would be nice (for me) to have some “knock-out” argument against such positions.

I agree with this also. In fact, I think that many phenomena in QM might be rendered explicable if we adopt an a-temporal notion of causation and allow for (within very strict limits) the possibility of some effects temporally preceding their causes (so along as no “information” is allowed to be sent back in time). However, there are many alternative interpretations of such phenomena in QM and we have no idea which one, if any, is right.

Well, yes, the standard interpretation of GR is that there is no privileged reference frame and hence no universal definition of “now.” However, as I understand it, there is an alternative interpretation of GR which takes GR as nothing more than a recipe for translating the measurements of one reference frame into another, but that GR is silent on whether or not there is in fact any single reference frame which is metaphysically privileged (more on this later).

Well, it seems that no matter how we slice it, in the case of GR, that some significant aspect of our experience is nothing more than an “artifact of measurement.” Our everyday experience seems to indicate to us that there is a definite “now” and that time flows from past to present to future. The standard interpretation of GR tells us that this aspect of our experience is an illusion created by our being confined to a particular reference frame. An omnipresent/omniscient being would perceive the universe as a static four dimensional space-time object with no universally defined “now” (this is, in fact, how I think that God perceives the universe).

However, the non-standard interpretation that I have described above flips things around. There is a metaphysically privileged reference frame which defines a universal now (even if we don’t know what that reference frame is). Our subjective experience of the flow of time is real. Relativity of simultaneity is the illusion -- caused by the fact that our measurements of space and time are mediated to us via electromagnetic fields and those measurements get distorted by the effects of motion. If we knew what the metaphysically privileged reference frame was, we could use the equations of relativity to translate our measurements into the that reference frame and thereby compensate for the “distortion” that motion introduces into our measurements. An omniscient/omnipresent being would perceive a universal present.

Suppose, for instance, that Anne’s twin sister Betty sets out on a journey from the earth to a distant star traveling at .8c (.8 times the speed of light) at twelve noon (in the time zone Anne and Betty both set their watches by). For simplicity’s sake, let’s assume that Betty’s super sub-light-inertial-dampening drive allowed Betty to accelerate to this velocity instantaneously without being crushed. At this velocity, Betty experiences a time dilation factor of .6. Twenty four hours later, Anne’s time, Anne is eating lunch and wonders if Betty is doing the same “right now.” But, then Anne realizes that since Betty is traveling near the speed of light, Betty’s time is running slower and that Betty hasn’t reached noon yet. So Anne calculates that for Betty, not twenty four hours, but .6x24 = 14.4 hours have passed, and so for Betty the time is now only 2:24a this morning. “Betty is probably asleep right now,” Anne thinks.

It’s lonely in space and Betty cannot sleep very well. At 2:24a, she wonders what her sister Anne is doing. Of course, in Betty’s reference frame, it is not herself that is moving at .8c and experiencing a time dilation factor of .6, but the earth and Anne along with it. Betty calculates that, for Anne, not 14.4 but .6x14.4 = 8.64 hours have elapsed. “For Anne, it’s still 8:38p the previous day,” Betty thinks. “I’ll bet Anne hasn’t even started getting ready for Bed yet.” “In fact,” Betty thinks, “by the time Anne is eating lunch tomorrow, from my perspective, (1/.6)x24 = 40 hours will have already gone by since I left Earth.”

Obviously, Anne and Betty have radically different notions of what time it is for her twin sister “right now.” Who’s right? Well, on the standard interpretation of relativity, they both are (or neither are, depending on how you want to look at it) since there is no universally defined now. But on the non-standard interpretation I described, its possible that one of these twins might be right and the other might be wrong.

Suppose the earth is in the privileged reference frame. Actually, if the non-standard interpretation of relativity is correct, this may not be that far from the truth. If there is any plausible candidate for a metaphysically privileged reference frame that I can think of, it would be the reference frame in which there is no measured Doppler shift in the cosmic background radiation. It is this reference frame which cosmologists privilege when they calculate such things as the age of the universe, and the movement of the earth with respect to this reference frame is negligible as far as relativistic effects are concerned. Anyway, in that case, Anne’s assessment of the situation would be the correct one and Betty’s the false one. An omnipresent/omniscient being would see that there is a universal now and a universal definition of simultaneity, but that Betty’s motion with respect to the privileged reference frame is distorting Betty’s measurements. However, if Betty were aware of what the privileged reference frame was, she could easily have compensated for her measurement “error” by taking relativistic effects into account.

I feel the same way, but I am less confident in that perspective than I once was. Of course, it is still possible for God to possess foreknowledge even if time really does “flow” and the future does not exist, but how one views the metaphysics of time plays a rather large role in that theological discussion. Even apart from the theological content, however, the discussion of the metaphysics of time is interesting in and of itself and has a very large impact on our understanding of reality.

God Bless,
Kenny

bd-from-kg

sandlewood:

Well, yes, in a sense. But I was trying to describe an aspect of general relativity. You seem to be describing an existential fact about human experience. Thus, it would be true in your sense that “there is only now” regardless of whether Newtonian physics, general relativity or some completely weird set of physical laws that no one has even imagined were true. This way of speaking isn’t wrong; it’s just not useful in the present context.

Sure. The one who stayed on earth says that it’s “now”, meaning 8:15 AM, July 17, 2077, while the one who traveled says that it’s “now”, meaning 9:47 P.M., April 5, 2014.

Well, yes. More specifically it’s describing (among other things) the rate at which things change as measured in different reference frames.

Actually this isn’t staying especially on topic. If determinism is true and there is therefore no such thing as libertarian free will, God’s foreknowledge is not problematic. Of course God has foreknowledge if the universe is deterministic. What troubles Taffy and leads him to the curious position that God does not necessarily have foreknowledge is, I suspect, that he thinks that divine foreknowledge is incompatible with libertarian free will.

It’s definitely not the latter. QM says that the two particles both initially have indeterminate spin, but that these spins are “entangled” in such a way that if you measure each one’s spin along the axis in question (before doing any other measurements on either) you’ll get opposite values. (The only possible values are +1 and –1 in the appropriate units, so this means you’ll get +1 for one and –1 for the other.) The idea that the two particles had definite but unknown spins all along, and all that happened is that these spins were measured, is a simple example of what’s called a “hidden variables” theory. Hidden variables theories seem to have been pretty much ruled out by a large number of experimental results by now. (The details are rather complicated.) But the measurement of A cannot “cause” particle B to assume a definite spin either (at least as causes are ordinarily conceived), because there are coordinate systems in which the measurement at B occurs before the measurement at A. Even if you’re willing to talk about an effect that precedes its cause, the situation is completely symmetric, so that it is just as “correct” to say that the measurement at B causes particle A’s spin to assume a determinate value of +1 as the other way around. It really looks as though this situation cannot be understood properly in terms of “cause” and “effect” if we interpret these terms in anything like the “ordinary” way.

bd-from-kg

Kenny:

I noted some objections to this position, but they don’t seem to be absolutely fatal. To me this is just a matter of how one chooses to talk about such things. It seems likely that there is a logically consistent meaning for “proposition” for which this is true. As Swartz points out, this would also require a very significant revision in our standard logic, since the law of the excluded middle wouldn’t hold and propositions would not have “time-independent “ truth values. Hardly seems worth the effort.

I’m not sure that there’s a “knock-out argument” against such positions. But it seems to me that there is absolutely no reason to embrace them. The basic impetus behind such positions seems to be that foreknowledge is incompatible with libertarian free will, and this is simply false. (Swartz has a very nice discussion of this on page 3 of the document I cited earlier.) Since you can have your cake and eat it too, why give up either?

Yes. In fact, that’s what the transactional interpretation does. But this still leaves us with the problem that the temporal relationship between events that are “causally” related in this extended sense is sometimes ambiguous. Which of course implies that the “present” is indeterminate. God can’t be said to “know” the present and not the future unless the term “the present” has a definite meaning.

This isn’t just the “standard interpretation”; it’s the fundamental insight behind relativity. It was precisely Einstein’s recognition that a great many otherwise inexplicable anomalous results could be explained if the laws of physics are assumed to be invariant in all inertial frames – in other words, that there’s no preferred frame in which these laws take on a simpler form - that led him to the theory. The basic equations, including the famous equation E = mc², were derived mathematically from this assumption. And I don’t see how the prediction that if you combine certain elements in a certain way you’ll get a huge explosion can be regarded as the consequence of a “recipe for translating the measurements of one reference frame into another”.

Anyway, GR is the most elegant of all physical theories in the sense that the entire framework can be derived rigorously from a very few fundamental assumptions. To regard this fact as mere happenstance – as a lucky accident which has nothing to do with the underlying reality – is implausible in the extreme. If dozens of facts can be explained by the hypothesis that Smith killed Jones and can only be explained otherwise by dozens of ad hoc hypotheses, this is ordinarily regarded as proof beyond a reasonable doubt that Smith killed Jones.

I really don’t understand how this is supposed to work. For example, the clocks in the GPS satellites run a little faster than clocks on Earth do. (This isn’t a matter of the reference frame in which they’re measured; they “compare themselves” to Earth clocks all the time and both “agree” that the satellite clocks are running faster. The reason is that they’re not as deep in earth’s “gravity well”. All in accordance with GR’s predictions.) Note that this has nothing to do with the fact that the satellites are moving; they move only because it’s necessary to keep them from falling. If we could maintain a GPS device in a fixed place relative to Earth we would see the same effect. (To be more precise, we’d still see an effect: the movement of the satellites has some effect on the clocks too.)

To say that one reference frame is “privileged” when there are nearby frames (which remain close) where clocks go at different speeds seems to me to be unintelligible. In what sense is the “time” measured by clocks in the one frame more “correct” or “true” than that measured in the other? If the clocks in the “non-privileged” frames aren’t measuring time, what the heck are they measuring?

All true, but as I assume you know, when they get back together there will be no such disagreement. (And not just because they can compare their watches directly; if Betty has calculated here speed, etc. correctly, she can predict what Anne’s watch will show, and it will be consistent with what she “thought” Anne’s watch was showing at all times during the journey.) The only discrepancy is in what they think of as “now” at distant points, which arises because they’re operating in different reference frames.

But one thing that is not possible is that the twins’ watches will show the same time when Betty gets back home.

But this is not an inertial frame! In fact, it looks really weird near massive objects, especially black holes. But even if the distribution of matter were uniform it would be radically noninertial on a cosmic scale.

Anyway, I see no point in postulating a supposed “privileged” frame given that this is directly contrary to the most fundamental assumptions underlying GR, that it is completely unnecessary, and that there is no way to define such a frame “operationally”. This sounds like an attempt to reintroduce the “ether” under another name.

Since this supposed frame and its associated “time” are completely undetectable in principle, you could just as well postulate a frame in which time flows, say, a billion times faster or slower than it does in any observable or definable reference frame. In other words, this frame can only be said to “exist” in an abstract, metaphysical sense. It has no connection to the “real world” – the observable universe. The hypothesis makes no predictions, does not provide any “unifying conceptions” that would help us to organize or interpret our experiences, etc. In short, scientifically speaking it is completely out of court.

Once you begin to take seriously proposals that something might exist merely because you can imagine it, you have departed the realm of the rational and entered never-never land.

7thangel

I guess that is one subject where theists fail in convincing atheists, and also of them arriving at irrational doctrines.

The Bible says "ALL" things were made by God, "VISIBLE OR INVISIBLE." How come that theists confess God knows what will happen; as if there is another power doing other things? Even if there are other powers that exists, God is responsible of their existence, and therefore should have knowledge of them. Or theists will come to picture a God who suffers a lot of failures.

I believe that all things, good and evil, and of the fate of the future is all the works of God. The same good and evil that exists gives us knowledge of good and evil. Our knowledge of good and evil is itself that makes us more glorious in being than other created things.

Kenny

Bd-from-kg,

Thanks for the discussion. This will be my last post on the matter. As you well know, I have another thread I need to be working on I would also like to say that I’m trying to defend this position in order to challenge my own. Since I don’t really believe in the viewpoint I’m defending on this thread, it may be that I am not able to present the strongest case that could be presented for it. In fact, I think most of your objections are very cogent.

Yes, I understand that. In fact, I’ve done many of those derivations myself. But, this interpretation is not challenging the principle of invariance with respect to the laws of physics. It is challenging the notion that there is no metaphysically privileged reference frame. The question before us is not whether the laws of physics are invariant in all inertial frames, but whether relativity implies that the “flow” of time, that we seem to perceive, is really just an illusion. It seems that if time really does flow, as our experience suggests, then there must be some metaphysically privileged reference frame by which that flow is defined, even if the laws of physics themselves are invariant across all reference frames.

But since this interpretation is not challenging any of those assumptions, this is not at issue.

On this interpretation, their measurements are being distorted by gravitation and motion. The equations of relativity, combined with a knowledge of what the privileged reference frame is, tell us how to correct for these distortions.

Well, I think that those who would defend such an interpretation would argue that the standard interpretation of relativity fails to take our qualitative experience suggesting that time flows seriously enough. They would argue that such experience gives us insights into the metaphysical nature of time that are missed by quantitative physical theories.

However, I think that our qualitative experience can be explained just as well and far more simply without having to resort to postulating a notion that time flows and the metaphysically privileged reference frame that would have to accompany such a notion. Our conscious experience of a succession of temporal states, I think, is easily accounted for if we recognize that such a succession really does exist, but as part of a four dimensional space-time geometry, not a mysterious “flow” of time.

God Bless,
Kenny