G. J. Whitrow. “The Significance of Time.” Chapter 1 of What is Time? (New York: Oxford University, 1972).
***
{ background: some information about the “block universe” theory of time—that all times coexist, and that the universe is a four-dimensional block—as well as that theory’s alternatives:
<http://www.ipod.org.uk/reality/reality_block_universe.asp>
And (linked within the above), Paul Davies’ article in Scientific American
<http://www.ipod.org.uk/reality/reality_mysterious_flow.asp> }
***
Notes on the text:
p 128
According to Plato (Timaeus)
Natural law prefigures the universe, and is timeless, provided by ideal forms in a state of rest (abstract, unchanging)
Space = a preexisting framework, in which the universe exists, but
Time produced by the universe, by its fluctuation and change
Time = “that aspect of change which bridges the gap between … the material universe and its ideal model.”
p 129
According to Bertrand Russel
“Past and future must be acknowledged to be as real as the present, and a certain emancipation from slavery to time is essential to philosophic thought.”
p 130
“Time’s arrow depicts the irreversible before-and-after succession of events”
“Time’s passage refers to the distinction that we make between past, present, and future.”
p 131
According to M.J.E. McTaggart
Time must be an illusion because
1. An event must never cease to be an event, and as an event, must never cease to have whatever characteristics it has, except
2. Its characteristics in relation to time, that its status as a far-future event, near-future event, present event, near-past event, etc. are in constant flux
3. the time at which a future event is past is in the future, the time at which a past event is future is in the past, and those times are also events, i.e. the changing state of an event as past, present and future is a state that also proceeds through time
p 132
Whitrow: McTaggart’s error is to treat time itself as a process in time.
(Discuss: analogy in time-travel movies—the characters always go either forward or backward in time, and then proceed back to the present. In what temporal framework does this “and then” occur? Is there any temporal sense in which H.G. Wells, or Marty McFly, were once in another time, and are now “back”?)
For a meteorologist or paleontologist, the concept of “now,” and the transitional nature of the present moment, is a crucial feature —
(BLC: in contemplating processes unfolding in the past (paleontology) in terms of their having caused the enigma present evidence, or unfolding in the future (meteorology) in terms of their predictability in light of present evidence, the role of the present as a moving divisor, is essential.)
But for physics and some philosophical endeavors, it’s adequate to regard the significance of the present moment as an illusion; it is “sufficient to concentrate on the relations of ‘earlier than’ ‘later than’ and ’simultaneous with’.”
“Some philosophers have argued that one cannot define the present except in reference to itself…there is no reason to suppose that what it defines has objective significance…Instead of accepting this view, can we establish the objectivity of past, present, and future?”
p 134
“In practice, we do not normally encounter [discrepancies between subjective experiences of “now”], and the world would be much more complicated if we did.” —> (BLC: within what contemporary physicists sometimes refer to as an “event horizon”, the concept of now has an objective, unifying reality, in that contiguous parts of the known universe respond in a unified way to similar impacts upon them… )
… “if the universe admits a common cosmic time for observers fixed in the galaxies (emphasis mine) then in terms of this cosmic time all events have a unique time-order.” and “we come back to Plato’s idea that time and the universe are intimately associated.”
Atoms of Time
“The plausibility of these assumptions…that time is homogeneous and continuous…was…greatly strengthened by the development of precise methods and machines for the measurement of time…[and] by the general decline of belief in traditional [uneven] temporal associations” with seasons, “magical” notions of 7-year life cycles, and other cyclical/agrarian conceptions of time’s passage.
p 135
Puritan “routine of six days of work followed by a day of rest,” along with other industrial notions of time, were “an important step toward the social acceptance of the modern notion of time as even in quality, as opposed to the primitive sense of time’s unevenness and irregularity.”
“Nowadays most of us tend to accept automatically the idea that time is continuous because we believe i nthe continuity of our existence.
p 136
“The continuity of time” can be “called into question…Instead of time being infinitely divisible…like matter and energy, it may be atomic or granular in structure.”
Corresponding to the material and atomic structure of space, a chronon “might be the time required for light to cross” minimum spatial displacements in an atom… “the possible existence of a chronon is a revolutionary idea that calls into question a fundamental feature both of the scientific idea of time that has prevailed in recent centuries and of the popular conception of time that most people accept intuitively.”
Precognition and the nature of time
“Another of the traditional properties of time that has also occasionally been called in question in recent years is its unidimensionality.”
p 137
“Suppose I precognize an event which is to occur next Sunday. In one respect — that is to say, in one dimension of time — this event has not yet come into being: it is still future and does not yet exist. But in another respect, or second dimension of time, it is past and so has already come into being.” (Demonstrate visually w/ Cartesian coordinates.)
Philosopher C.D. Broad:
(GJW paraphrasing: “the phrase ‘future event’ does not describe an event of some special kind, as the phrase ‘sudden event’ or ‘historic event’ does. Instead, a future event is nothing but an unrealized possibility until it comes to pass and therefore can itself influence nothing, although the present knowledge that there will be such an event can influence our actions when it is called to mind…”
p 138
“the hypothesis of two-dimensional time is…not required to explain [such cases].”)
The transitional nature of time
“In a block universe, as we have seen, past, present and future do not apply to physical events, and so they neither come into existence nor cease to exist — they just are.”
“If we inhabited a block universe, mental events would have a completely different kind of existence from physical events.” (Destruction of cause and effect.)