Showing posts with label arrow of time. Show all posts
Showing posts with label arrow of time. Show all posts

08 July 2018

Is Time What It Appears to Be?

Posted by Keith Tidman

Picture credit: Shutterstock via https://www.livescience.com/

“Time itself flows in constant motion, just like a river; for neither the river nor the swift hour can stop its course; but, as wave is pushed on by wave, and as each wave as it comes is both pressed on and itself presses the wave in front, so time both flees and follows and is ever new.” – Ovid
We understand time both metaphorically and poetically as a flowing river — a sequence of discrete but fleeting moments — coursing linearly from an onrushing future to a tangible present to an accumulating past. Yet, might ‘time’ be different than that?

Our instincts embrace this model of flowing time as reality. The metaphor extends to suppose a unidirectional flow, or an ‘arrow of time’. According to this, a rock flies through a window, shattering the glass; the splinters of glass never reform into a whole window. The model serves as a handy approximation for our everyday experiences. Yet what if the metaphor of time as a flowing river does not reflect reality? What then might be an alternative model of time?

What if, rather than the notion of flow, time actually entails only one now. Here, an important distinction must be made, for clarity. That is, time is not a sequence of ‘nows’, as proposed by some, such as the British author of alternative physics, Julian Barbour. That is, time is not points of time — corresponding to frames in a movie reel — with events and experiences following one another as ephemeral moments that if slowed down can be distinguished from one another. But, rather, time entails just one now. A model of time in which the future is an illusion — it doesn’t exist. The future isn’t a predetermined block of about-to-occur happenings or about-to-exist things. Likewise, the past is an illusion — it doesn’t exist. 

As to the past not existing, let me be specific. The point is that what we label as history, cosmology, anthropology, archaeology, evolution, and the like do not compose a separately distinguishable past. Rather, they are chronicles — memories, knowledge, understanding, awareness, information, insight, evidence — that exist only as seamless components of now. The Battle of Hastings did not add to an accumulating past as such; all that we know and have chronicled about the battle exists only in the now. ‘Now’ is the entirety of what exists — all things and all happenings: absent a future and past, absent a beginning and end. As the 4th-century philosopher St. Augustine of Hippo presciently noted:
‘There are three times: a present time about things past, a present time about things present, a present time about things future. The future exists only as expectations, the past exists only as memory, but expectation and memory exist in the present’.
In this construct, what we experience is not the flow of time — not temporal duration, as we are want to envision — but change. All the diverse things and events that compose reality undergo change. Individual things change, as does the bigger landscape of which they are a part and to which they are bound. Critically, without change, we would not experience the illusion of time. And without things and events, we would not perceive change. Indeed, as Ernst Mach, the Austrian philosopher-physicist, pointed out: ‘... time is an abstraction, at which we arrive by means of the changes of things’.

It is change, therefore, that renders the apparition of ‘time’ visible to us — that is, change tricks the mind, making time seem real rather than the illusion it is. The illusion of time nonetheless remains helpful in our everyday lives — brown leaves drop from trees in autumn, we commute to work sipping our coffee, an apple rots under a tree, the embers of a campfire cool down, the newspaper is daily delivered to our front door, a lion chases down a gazelle, an orchestra performs Chopin to rapt audience members, and so forth. These kinds of experiences provide grounds for the illusion of time to exist rather than not to exist.

As Aristotle succinctly put it: ‘there is no time apart from change’. Yet, that said, change is not time. Change and time are often conflated, where change is commonly used as a measurement of the presumed passage (flow) of time. As such, change is more real to the illusion of time’s passing than is our observing the hands of a clock rotate. The movement of a clock’s hands simply marks off arbitrarily conventional units of something we call time; however, the hands’ rotation doesn’t tell us anything about the fundamental nature of time. Change leads to the orthodox illusion of time: a distinctly separate future, present, and past morphing from one to the other. Aristotle professed regarding this measurement aspect of time’s illusion:
‘Whether if soul [mind] did not exist, time would exist or not, is a question that may be asked; for if there cannot be someone to count, there cannot be anything that can be counted.’
So it is change — or more precisely, the neurophysiological perception of change in human consciousness — that deludes us into believing in time as a flowing river: a discrete future flowing into a discrete present flowing into a discrete past. The one-way arrow of time.

In this way, the expression of dynamic change provides our everyday illusion of time, flowing inexorably and eternally, as if to flow over us. The British idealist philosopher J.M.E. McTaggart wrote in the early years of the twentieth century that ‘in all ages the belief in the unreality of time has proved singularly attractive’. He underscored the point:
‘I believe that nothing that exists can be temporal, and that therefore time is unreal.’
To conclude, then: Although the intuitive illusion of time, passing from the future to the present to the past, serves as a convenient construct in our everyday lives at work, at home, and at play, in reality this model of time and its flow is a fiction. Actual experience exists only as a single, seamless ‘now’; there is no separately discrete future or past. Our sense of time’s allegorical flow — indeed, of time itself — arises from the occurrence of ‘change’ in things and events – and is ultimately an illusion.