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Julian Barbour on does time exist

by julian
Tags: barbour, exist, julian, time
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mattmars
#163
Dec25-12, 09:07 AM
P: 4
Hi Marcus,

Thanks for those posts and I appreciate those links, I’ll look through them. (in particular the ‘emergent’ aspect etc). I want to air all my thoughts on many of the points you raise (because I genuinely think I have a meaningful answer to each of them), but that would create a massive post. So as I read up on the areas you’ve pointed to I`ll post some thoughts on a select few.

I`m drawn to this post ‘Julian Barbour on does time exist’, because of it’s title, and because like Julian I have also written a book (eBook) on the nonexistence of time – but from a significantly different and far simpler angle. ( search for ‘A Brief History of Timelessness’ + you`ll find the site/videos/book etc)

I appreciate your ‘angle’ on mathematics, but I really think the essence of the ‘problem’ can be expressed in simple plain English, and, what I see throughout all the discussions about ‘time’ I have read, (which is a lot), is the more sophisticated the conversation gets the more the basic issue gets irretrievably obscured. Effectively people end up considering questions that cannot be answered – because they may be based on very basic incorrectly made assumptions.

(For example if we ask the question which is probably the more correct view of time, Newton’s fixed and universal time, or Einstein's dilatable space time? Many people would start considering that obviously Einstein's view of time has been theoretically and practically proven to be more correct. However, I would say both are ‘completely’ wrong in that there is no such thing as time, at all, period. Einstein's work is clearly correct and proven in many ways, (Mercury’s advancing perihelion, gps etc), but (imo) it is not about a thing called ‘time’, it is just and only about the way things move (‘now’ to use a redundant and slightly misleading word).

Normally saying Einstein's view is better than Newton’s doesn’t matter. But if people assume this thus means it is a forgone conclusion that a thing called ‘time’ in some way exists, and Einstein's view of it is more refined, and now we just need to refine the view further- then they may never recheck the fact that the existence of the thing actually isn’t proven by either view. And I’ve got a stack of books all about time, virtually all of which are written as if ‘time’ exists, built on the idea that Einstein's work in some way proved times existence.

For example, as I say I`m drawn to this post because of the title, ‘Julian Barbour on does time exist’. I read Mr Barbours very well written and comprehensive book (‘The End of Time’) as careful as I could, in case his point was the same as mine, but it’s not.

The End of Time p143, Mr Barbour says ‘The block universe picture is in fact close to my own’,(I think)... he then describes a kind of ‘phase space of infinite dimensions’ in which all possible configurations of all the matter in the universe constantly, and statically exist. And in which all possible ‘historys’ statically exist – such that as we ‘move’ through particular paths in this infinite phase space it appears to each of us that ‘time’ with a past and future exist.

(Note that is just my own very rough understanding of what I think Julian is saying, the maths etc in the book is out of my league so I may have got that wrong).

In my opinion, this is an example of just how complicated things get if we have incorrect, unchecked assumptions at the core of a ‘theory’, and, if we ‘follow’ the maths searching for an answer to a problem that does not exist.

My approach...

My approach very briefly (I’ve expressed the whole thing on the website), to me the idea of “’time’ being explained by all possibly histories constantly existing’, or the question ‘”is ‘time’ emergent (or not)?” become redundant and moot if we just consider the following question very carefully (as I mentioned in my 1st post)

Do we actually have any legitimate reason to even suspect that (say) the term ‘the past’ in any way at all actually relates to some ‘thing’?

It seems to me that the only reasons we even consider that a thing called ‘time’ might exist (or be emergent) is because we think our ‘memories’ indicate some kind of a ‘past’. But if we see that there is absolutely no reason at all to suspect that our ‘memories’ are anything at all other than ‘a collection of ions and electrons etc in a particular formation in our heads’ – then we can see that there is no reason at all to suspect ‘a (temporal) past’ exists in any way at all.

And if we are wrong to think there is ‘a past’, then we have no reason to suspect there is ‘a future’. And thus wrong to suspect there is a thing called ‘time’, or that ‘it’ has a flow or a direction. i.e (imo) it just does not exist and we are wrong to think it may.

Instead – the world is just as it appears to be – full of stuff moving in organised and/or chaotic ways. Whatever is true of QM is true of QM, but it needn’t have any component of a thing called time mixed in it. The universe may be expanding and heading for a heat death (or not) – but that may be ‘just’ what it is doing. Just because the universe is expanding in an ‘irreversible’ way, doesn’t mean there ‘is’ a past or a ‘future’ – or time, or an arrow of time.

Likewise , if things ‘just’ move and change etc , then ‘time’ is not emergent... things jjust move and change. Calling this ‘time’ and asking if it is emergent is (to me) like asking if ‘movement is emergent from movement’.

I appreciate what you say about the ‘Tomita flow time’ (tho I haven’t read up on it yet to be honest), but when I consider the ..

“subtle difference in the way we TREAT intervals of time and the changes that correspond to them”

My position is that there are no ‘intervals’ of ‘time’. We can sit in front of a motorised hand that is rotating around a numbered dial (a clock) – but just because we are breathing and that hand is rotating does not prove that there are such things as ‘intervals of time’ – or that a thing called ‘time’ is ‘passing’.

Its a odd concept to see if we are deeply ingrained that ‘time’ makes sense in some way, but if theres no past and no future, then there’s no time and ‘passage’ or intervals of it. And useful as the maths is, we may say t1+t2 =t3, and if time exists this may be valid, but in itself I don’t think this shows that ‘time’ exists,

-ok, i’ve hit 1000 words again, and i`m duplicating points, so i`ll stop. Please don’t think i`m ignoring the things you have pointed to, these are just my views at the moment – having written my book on the subject.

Sorry I haven’t. Addressed the issues you pointed to directly, I will read them in detail, and you're right I should (will) read earlier points of the thread, (just busy due to xmas), I just wanted to send this post before I take the xmas break.

Matt marsden (brief history of timelessness)
marcus
#164
Dec25-12, 11:01 AM
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Interesting thing about Barbour is if you look at what he is actually saying, e.g. http://arxiv.org/abs/0903.3489
he shows that a time variable does not have to be put in "by hand" at the beginning of the analysis, but can be DERIVED from observation.

In this case he derives the evolution parameter from observing a dynamical system---a bunch of planets, or other bodies---stars, satellites, whatever.

This derivation us purely classical = non-quantum. The Tomita method is analogous in the sense that the evolution parameter is DERIVED (from correlations among observations) rather than put in by hand at start of analysis. However it is not limited to classical systems--can be applied to quantum ones as well.

As I think I said earlier in thread, I don't think "time does not exist" is an accurate headline for what Barbour and Connes-Rovelli are saying. "Exist" is a kind of fuzzy word anyway---more philosophy than science. Time remains a crucial indispensable and all-important element in their analysis, what they show is that it can be derived from other stuff.

In a sense that makes time all the more real because you cannot avoid it. It is implicit in what we observe.

As I said earlier, the headline "time does not exist" would be primarily an attention-getter, not an accurate summary of what Barbour or the others are saying. Perhaps a better (but less strikingly worded) summary would be "time is inherent in natural processes and can be derived from observation".

Since I'm currently very interested in the strategies used to derive time from observations, it actually does NOT get my attention to say "time does not exist". It may work for other people, though.

I think a frank answer, by Barbour, to the question does t exist (in thread title) would be YES INDEED it exists and it is very interesting how one can mathematically derive it!
berkeman
#165
Dec25-12, 11:58 AM
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