∆ A Brief History of Time.
(From the paperback 'A Brief History of Time' page 161)
This excellent and ground breaking book launched a tremendous surge of interest in cosmology.
But it actually says very little about why we should assume 'Time' exists, and what It does say does not prove the existence of Time.
In "A Brief History of Time" , professor Hawking states "we can remember the past but not the future".
this statement suggests he has a proof that 'the past' is in some way a thing that exists, and that we can 'remember'
this implies the professor assumes his, and our 'memories' are sufficient reason to assume a past, and thus time, exist.
but logically our 'memories' are just some of the universe ( possibly always, just , existing) - in a particular formation.
(ie similar to a foot print impression in mud - all just here, in a stable formation of matter)
as we move around the world, light is hitting our eyes , etc, and this is causing the matter , ions, electrons, etc in our brains to be being reorganized in places.
some of these created formations may be stable, or unstable, but to call stable mental patterns , ones 'memories of the past' - is invalid scientifically unless one can prove this 'past' that is mentioned actually exists.
and more importantly one can show ones reasons for assuming memories are 'of the past' , and thus that the past exists - are not circular - ie based on the idea the 'memories' them selves are of the past, because THEY prove the past exists.
likewise one needs to prove 'the future' is not just an idea.
in otherwords, where Hawking says "we can remember the past but not the future".
perhaps what he actually describes is,
"the fact he can access certain stable mental impressions that exist in his mind (misleadingly called “remembering ‘the past’ “), but he can not accurately model certain chaotic changes that are happening around him ( and calls this "not seeing 'the future' " ) .
entropy
In my opinion, the 'increase of disorder or entropy', is just that. We seem to live in a universe where everything is indeed constantly dissipating into disorder, or winding down towards a 'heat death' so to speak.
This does suggest that locally, and as a whole, things are on average falling apart. but it does not show that there is also a thing called time, that has a directions, and is related to this entropy. i.e causes it, or is driven by it.
if we try to say 'ahh but this 'entropy' is what we mean by time, and by time arrow' - then we are agreeing that 'now' is unfolding unstoppably in one direction' but 'there is only now' - so time exists... but just now.
Of these 3 (apparent) arrows of time, Thermodynamic, Psychological and cosmological,
- The Thermodynamic and cosmological arrows are very similar, and just examples of things expanding and cooling down. And, if Time is proven to exist by some other observation, then these examples will confirm that it has an arrow or direction.
But alone they just confirm that matter can exist, and spread out in essentially one direction if that's what the laws of physics dictate.
See...Entropy, Is not also 'Time'.
-The Psychological arrow of time, just relates to the fact that as we live and eat and breath we physically change the contents of our minds to accumulate information. To do this, matter must be able to exist, move and interact. If time exists, and if it creates another 'temporal' record of events as they happen - then our memories will confirm this and tell us something about 'the past'.
But , alone, the physical contents of our minds here, now, just prove that stuff can exist and change here now. Thinking otherwise is the trap of taking evidence that 'seems to confirm' a guess, as being 'proof' of the guess.
in other words, if you ask the question
'if matter just existed and interacted, could this give a human brain the illusion that there was a 'universal' forward progression of a thing called time ?
you may find he answer is surprisingly 'yes'.
see...Timeless memories.
Perhaps it makes sense to take the analogy literally. If you examine an arrow you will see that it is a thing that is here now, and can travel (now) in one direction, from place A to place B -if it is given an energetic shove- but as it does so it does not also prove that as it heads for 'B' it is also heading into 'the future' - or as it leaves 'A', it leaves the past behind it.
None of this is to deny the apparent one way unfolding of the universe - (although I like to think it will bounce back)
- but to say if we have no proof of any trail of 'temporal past' behind us, and if the 'future constantly arriving' can be explained much more simply as us just misunderstanding the way energy can be released in orderly or chaotic ways - then - we see no moment behind us, no instant ahead of us, so this apparent 'time dimension' has no 'length' and things are probably just as they constantly appear - all here now.
m.marsden.