In Search of Time

"Is time nothing more than change? Or is time more fundamental - is it the mysterious entity that makes change possible, a kind of foundation on which the universe is built? Or is it just the opposite: as much as we like to speak of the 'river of time', could the river be dry, its flow an illusion? (And how can it flow if it is meaningless to speak about the rate at which it flows?)" - Dan Falk, In Search of Time (2008), p. 273.

Reading this book (which I really enjoyed) brought to mind our friend Simon the physicist and the nature of time in his hypothetical universe. So as to not admit such tendencies in myself on the record, we'll also introduce the fact that Simon the physicist likes to drive fast. He also likes to be the first one to respond to the green light after being stopped at an intersection. It's a weird compulsion that he has and we're not sure where it comes from. But he's very good at being the first one to hit the gas once a traffic light turns green. He's so good at this that he has sometimes wondered why he is so much faster than everyone else at responding to the green light...

I won't force Simon the physicist to take responsibility for the thoughts that follow, as they come from a distinctly-nonphysicist perspective. And I will credit Falk for putting together so many engaging ideas in such close proximity in his book, many of which prompted long chains of interesting thoughts. What follows is one of them, and may be total crap, but I sure had fun piecing it together.

Perhaps the biggest 'stop and think' idea I ran into while reading this book was the idea that "light, too, can affect time. Light carries energy, and Einstein had shown that mass and energy are equivalent - so light should also be able to warp space and time." (p. 181) Being conditioned to view our perception of light (and time and space) as functions of neural activity, my thoughts jumped to the path that a photon triggers once it hits the retina. Around this same time I was also reminded (by I remember not what) of the idea that processing speed may play a role in cognitive differences.

If neural signalling is ultimately the result of a transfer of energy, then the initial energy of the stimulus (photons) is quickly diminished or amplified by the unique dynamics of an individual's neural pathways - beginning as soon as the photon hits the first layer of cells in the retina. It follows then (without too much difficulty) that individual differences in neural/neurochemical dynamics affect how quickly something is perceived and/or reacted to. Neural density, differences in neural pathway configuration, and differing concentrations of neurochemicals may all impact the speed at which the original signal (photon) registers in conscious awareness. (This presumes that much of the early processing of the signal is not available to our conscious awareness: a view which is widely accepted and supported.)

So the question becomes... If our rate of perception is variable (even in the slightest degree), then can we not also reasonably say that time (or the rate at which we perceive change) moves at a different rate for each observer? And if time moves at a relative rate for each observer, then how/where can we say that time is an absolute feature of the universe?

But "clearly time appears to exist" (q) saith the physicist. Yes, but does it move at the same speed for everyone? And if it doesn't, then how do you and I reach an agreement that we both saw the same green light and I just smoked your [deleted]? What is present that underlies that observation? Do I functionally exist ahead of you in time if I can process and react to stimuli faster than you?

At this point the web of thoughts became tangled as I tried to connect special relativity to a model of multiple-observer dynamics. Trust me, you don't want me to go there. But do ponder that last question the next time you get smoked at an intersection. :)

And yes, I realize that I'm using a model/description that assumes an arrow of time in order to talk about how time doesn't exist in an absolute sense. It's interesting to think about how the effects of the reverse arrow of time might manifest themselves in that same model, but that's a topic for another post.