In a message dated 13/12/2009 05:04:53 GMT Standard Time, charles_steinm...@lavabit.com writes:
I think we all agree that intervals are what we measure. The question is whether this has any bearing on whether "time is an absolute quantity," and if so, whether time being or not being an "absolute quantity" is philosophically interesting. A number of us have been trying, without success, to get you to be more precise about what you mean by time "being [or not being] an absolute quantity," and how that might be important. As it stands, you have not done so, so we are left to guess what meaning and import this phrase has in your view. The two possibilities I see are that you mean (i) time has no ontological status -- that is, that it doesn't "really" exist, but is merely an imaginary construct that we impose on the universe; or (ii) even if time does have ontological status, it is not philosophically interesting unless it is "absolute" (whatever that means). What a number of us have been saying is that the way we measure time is purely conventional (and therefore, I suppose, "imaginary"), but that accepting this says nothing about either of these two issues -- i.e., whether time really exists or whether it is philosophically interesting. I take no position on the ontological status of time, but not because we measure it "only" in intervals or because it is not "absolute" (whatever that means). Rather, for me, it is an issue whether time -- as one dimension of spacetime -- can be a separate ontological entity. In my view, when Einstein, Dirac, Bohr, Lorentz, Schroedinger, and other "founding fathers" of modern physics spoke or wrote regarding the "existence" of time, this is the issue they were addressing. However, if we accept that spacetime exists, nothing is really riding on whether time is a separate ontological entity -- it has ontological status as a constituent of spacetime. So, the remaining question is whether the claim that time is not "absolute" (whatever that means) -- if true -- somehow renders the issue of time a merely semantic matter, or otherwise philosophically uninteresting. I don't see how this could be, but then I cannot imagine what you mean by time not being absolute, other than it can "only" be measured by intervals, and you have not explained what you mean in any but the most vague and circular terms. If you are able to articulate what it would be for time to be an absolute quantity, and how this would make a difference with respect to its ontological status or philosophical interest, I'll be happy to listen -- but I won't hold my breath. ----------------- Whoops, can't even hit the right buttons now, sorry about the earlier empty reply:-) I did agree it becomes a matter of semantics and I obviously wasn't explaining my thoughts at all well but I did start out purely with the intention of suggesting that a previous statement claiming "time just exists" was perhaps rather simplistic. However, that's perhaps more a reflection on common use of language rather than to imply that time iteslf is merely a matter of semantics or that it's anywhere near philosophically uninteresting. Whether or not time is, or more correctly can be expressed in terms of, an absolute quantity is certainly of philosophical interest to me. Outside of that though I wouldn't be so pretentious as to make claims of it actually having any importance:-) I use "absolute" in the sense that is commonly implied in the term "absolute quantity", where an absolute quantity is the measure of the absolute occurence of a variable, as in "so many volts, yards, kilos, etc. I probably should have explained it better but I think Didier hit it on the head when he commented...... "There is at least one thing that you cannot do with time, which you can do with pretty much everything else: you cannot go back and recheck your measurement. ..." I know one could argue that since time has moved on one can't actually measure the "same" voltage or whatever but let's ignore that for now. At one point in this "discussion" it was questioned what units I measured in but the actual units we use are totally irrelevant other than for day to day convenience, it's the existence and measurability of the quantity that's the issue. Perhaps "measurability" will now be called into task as another undefined term but hopefully that one's more obvious. If we accept for now that nothing, including time itself, existed before the Big-Bang, and yes I know there's suggestions that this might not be the case, then it becomes of interest to also consider the implications of that, which of course is hardly anything new. Whether or not one accepts that everything in the universe was initially collapsed into a singularity, even if we still haven't observed large parts of that "everything", it would seem that everything physical in that universe, including "space", fits my definition of "absolute". No matter how large or small, in one way or another, and in theory at least, it can be measured and quantified. The properties of what we call "time", however, are unique and lie outside of that categorisation. Time as such, unlike everything else, is not a physical entity that would have been collapsed into that singularity but can only have come about as a consequence of the ongoing expansion of material out of it that followed the Big-Bang. I know I've laboured to death the point about measuring time intervals but that's because it's really all we have. When considering whether or not time exists, perhaps we should first ask exactly what we mean when we refer to "time", do events occur "within" time, for example, or is time merely a consequence of events occuring? If the latter then does time have any real existence other than as a convenience to describe sequentiality, is spacetime really an entity or just a mathematical convenience, etc etc? So yes, it is vague and circular, and always with far more questions than answers. Whilst it doesn't in any way change the maths that we use when considering how things vary with "time", we shouldn't lose sight of the fact that our mathematical models are just that and again may not always exist outside of themselves either:-) regards Nigel GM8PZR _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
