Thursday, October 27, 2011

Making sense of time

To: Robert H.
From: Geoffrey Klempner
Subject: Making sense of time
Date: 5 October 2005 12:39

Dear Bob,

Thank you for your email of 27 September, with your Associate essay entitled, 'What Time is it Anyway?'

Like you, I am gripped by the problem of time, and specifically, the problem of finding a way to grasp, or explain the nature of McTaggart's A-series.

Amongst analytic philosophers, I would guess the majority would agree with Putnam that the only question that needs to be addressed is the nature of physical time. In his book, 'Real Time', D.H. Mellor argues that time is completely accounted for by the B-series. All the things that we want to say about the 'now' or about the distinction between past, present and future can be accounted for in terms of the B-series.

To give you a sense of what Mellor means, I will give the example of 'now'.

Mellor would offer the following as a logical analysis of the meaning of the concept, 'now':

The time is now XYZ if, and only if the time at which 'the time is now XYZ' is uttered is XYZ.

How does this work as an analysis?

On the left hand of the 'if and only if', there is a statement which uses the word 'now', while on the right hand side there is a statement which merely *quotes* the word 'now'.

As I write this, it is 12.01 pm British time. I can assert, truly, the following statement:

The time is now 3.33 pm if and only if the time at which 'The time is now 3.33 pm' is uttered (or written) is 3.33 pm.

Both sides of this equation are false, therefore the equation is true. If the left hand side had been true (if it had been 3.33 and not 12.01) then the right hand side would have been true also, so again the equation would have been true.

What is noticeable about this is the way the word 'now' seems to lose its essential meaning in referring to *now*, and just means any time you say the word 'now'. Every time is a 'now'. Now is just one now amongst billions of nows. Nothing special about it at all.

Intuitively, we feel this to be wrong. Now is different from all other nows, because it is actual, real, happening and not just a now that has already happened or has yet to happen. The difficulty is - and this is the difficulty that philosophers like Mellor and Putnam latch onto - is that whatever words you use in attempting to say what you mean by 'now' or the 'nowness of now' fail to accomplish their intended purpose. Whenever you attempt to describe *now*, the actual now, all you end up doing is describe some now. Your description is just as valid for any of the billions of nows that make up the history of the universe.

The sound of eight bells is no different from the position of clock hands or the shadow on a sun dial. It is physical event. We measure time, as you say, by comparing one process with another - the process of a clock, or the earth travelling round the sun. However, it could be argued that the *experience* of 'hearing eight bells', unlike the experience of just seeing the position of the hands on a clock or the shadow on a sundial, does capture something extra which the objective account of time in terms of the B-series is unable to explain. This seems to be the point of Husserl's essay on the phenomenology of time consciousness. But what is this experience?

To hear eight bells involves memory. But memory is not the same as a mental tape recorder. If I tape the sound of a clock striking eight, then the 'memory' or information stored on the magnetic tape still has to be played to be accessed; and it is the playing of it, rather than the storing of the information on tape (or in the brain) which constitutes the essence of temporal experience. What is it to hear the the 'dong' not just as a dong but as the third dong? How is the experience of its being the third dong presented to the mind? This is essentially the same question as the question how it is that we are able to hear a particular note from a tune as the note from that tune and not just, say, any old middle C.

It is a long time since I looked at Godel. Reichenbach was concerned with the 'arrow of time'. (He wrote a book with this title.) According to the B-series view, it is irrelevant which direction time is 'flowing' because time is just a static series of events. All the laws of physics can be reformulated to describe a universe where time travels backwards - e.g. where human beings are formed in the earth, then get younger and younger until the time comes to enter their mothers' wombs etc. etc.

Is that the case, or is there some extra fact about the physical universe, which has not been taken into account? The idea of a 'backwards universe' seems fantastical. Yet all that apparently distinguishes the 'forwards' and 'backwards' universes is the laws of probability, as exemplified in the Second Law of Thermodynamics. It is extremely improbable, but not physically impossible, that all the air molecules in this room will in the next second go in the same direction - towards the door - and I will be left gasping in a vacuum.

It might seem that conscious time - the A-series - is essentially unidirectional. But that hasn't stopped science fiction writers exploring the idea of what it would be like to live in the backwards universe. I remember reading a story with this theme but can't recall the author. Mind-bending stuff.

In your last paragraph, you raise the question whether, or how, a better understanding of subjective time would impact on abnormal psychology. It is plausible to say that for someone traumatised by an early experience in their childhood, there seems to be an inability to allow that this experience exists in the past. Bad things happen, and life goes on. Yet for some, it appears that life has stopped at that point, and they are condemned to endlessly act out the same scenario.

All the best,

Geoffrey