The Arrow of Time

I had watched The Fabric of the Cosmos on PBS’ NOVA hosted by Brian Greene from his book of the same title. Part 2 of “Time and Experience” deals with something we all think about (perhaps too much) and yet don’t really understand.

I have read a lot about and written quite a bit about time, particularly time travel which has long fascinated me. I have read many versions of the “time as a river” flowing past us (the observer) with the past downstream and the future upstream.

In this program, Greene talks about the “Frozen River” and questions whether time really does “flow.” What is interesting in this approach is that it touches on some ideas that we might once have read as fringe science or new age non-science.

Greene deals with Einstein and special relativity and is a big-time legit scientist, but I think that the first times I read about the idea that time does not flow and that all things simultaneously exist at the same time, was more likely when I was reading Carlos Castaneda rather than Einstein *.

No past, no present, no future. Just now.

As Einstein discussed, we “observers” moving relative to each other have different conceptions of what exists at a given moment, and hence they have different conceptions of reality.

There is also discussion of whether time has an “arrow.”  The arrow of time, or time’s arrow, is a term coined in 1927 by the British astronomer Arthur Eddington to describe the “one-way direction” or “asymmetry” of time.  The arrow appears to move forward from chaos to organization. Or does it? Was the Big Bang origin the most coherent and organized version of the universe, and we have since moved to greater chaos?

The laws of physics apply both moving forward in time and backwards in time – time-reversal symmetry.

Which brings us to entropy. Greene gives many examples (the series is full of animations and green-screen simulations) including broken glasses reassembling and such.  Entropy can be defined as a lack of order or predictability;  a gradual decline into disorder. The beginning of the universe must be the state of minimum entropy.

What always amazes me when I listen to Brian Green explain these unbelievably complicated concepts is that I completely understand them – until he stops talking – at which point my understanding vanishes.

Today I did some searching online to find out more about this arrow. Turns out there are several different arrows.

There is a  causal arrow of time.  A cause precedes its effect.  Birth, for example, follows a successful conception and not vice versa.  Dropping the wine glass is a cause and the glass subsequently shattering and spilling is the effect. It’s never that simple. Add in the thermodynamic arrow of time (see Second law of thermodynamics) and controlling the future, or causing something to happen, creates correlations between the doer and the effect.

How would we explain the pieces of the glass in reverse assembling precisely into the shape of a glass and flying up into the my hand (since the floor cannot throw and my hand can’t move objects without contact) and why would the liquid collect itself entirely within the cup?

Get into the particle physics (weak) arrow of time or the  quantum arrow of time and I am completely lost.

Perhaps, most of us would be comfortable with the psychological/perceptual arrow of time. That at least concerns things we understand – like our cataloging of items of memory from our perception. Things we remember make up the past. The future consists of those events that cannot be remembered.

Our sense of time comes from the perception is that continuous movement from the known (Past) to the unknown (Future).

In that psychological future, there are things (dreams, hopes) that are already a part of memory, but see to be ahead of the observer.

We (Westerners) associate “behind” with the past and “ahead” with the future, but that is a cultural association. According to what I have read, the Chinese and the Aymara people’s association are that ahead = past and behind = future. In Chinese, the term “the day after tomorrow” literally means “behind day” while “the day before yesterday” is referred to as “front day” and in Hindi (an Indian language), the term used for “tomorrow” and “yesterday” is the same.

So where am I right now?

My brief period of Buddhist training told me to be in this moment. No past or future, both of which lead to suffering.  We seem to only be able to live moving forward. We only understand the present by looking back. That doesn’t give us much “time” to spend in the present. And that seems to be a sad reality.

Now I will go for a walk in the woods. Walking forward, ahead, into what I think is the future, while trying to be mindful in the moments.

* Footnote: Born in 1925 in Peru, anthropologist Carlos Castaneda wrote a total of 15 books, which sold more than 8 million copies worldwide and were published in 17 different languages. In his writing, Castaneda describes the teachings of Don Juan, a Yaqui sorcerer and shaman. His works helped define the 1960s and usher in the New Age movement. Even after his mysterious death in California in 1998, his books continue to inspire and influence his many devoted fans.