Deep time – Essay
Deep Time –
This was an essay that I submitted for a competition. It had to include “time to tell”, and be 800 words.
One must understand deep time to tell the story of life on planet Earth.
Deep time is the timescale of the geological history of the Earth and, by extension, the timescales of the Solar System and the entire Universe.
Significant barriers obscure and frustrate our human conception of such long periods of time however. To creatures that live, on average, eighty odd years; ten thousand years or a million years, or several hundred million years becomes a difficult concept to fully comprehend. But why would one try to comprehend these large time scales one may ask? Well, there seems to be something in the human spirit that compels us to learn about ourselves in context, to tease apart the mystery of who we are, why we are here, and how we came to be here on this planet hurtling around our star, the Sun. To scientifically inclined minds, such questions are of paramount importance and tease the mind to stretch out across such grand timescales – to answer the large questions integral to our human experience.
How do we know that such large numbers are necessary for our understanding of the world? Well, the wondrous scientific method, a self correcting way of quantifying the natural world and our greatest guide to discover the truth of the story of time – shows us that both life and Earth are incomprehensibly old.
Like all good scientific results, various lines of evidence (garnered from various sources to prevent one source from contaminating the result) converge on a date for the age of the Earth to within a very small range, and determine the accuracy of that result to within a very small range of possible error. Geologists use the decay of various atomic elements in Meteorites and terrestrial rock samples – a process where these atoms give off “daughter” particles at a very precise and stable rate, to determine the age of the Earth (1).
The best radiometric dating methods indicate the age of the Earth at a staggering 4.54 billion years old (plus or minus 1% margin of error). At first glance the number is so large as to be meaningless, but if you are inclined to let the gravity of such a number enter your consciousness, and if you are patient enough in your stream of thought to sit and dwell on the number, then its full enormity starts to sink in – something happens to a mind in the grip of this number, this precise quanta of time filling the mind like the slow blade of water cutting a mountain. In the minds eye this can be the slow drip, drip, drip of moment after moment, building to a crescendo of time.
We live in an age of profound discovery, and an age allowing the clarity of perception, on an unprecedented scale, of not only the human story but the story of all things. This story is grounded by necessity in the context of large numbers representing very deep timescales. For example, the process of evolution – the slow change, over deep time, of genes in a population, expressing their battle for survival in the myriad of life forms that we see around us today, is a blueprint to the past, a living record of all the tiny steps that have gone into the making of the world as it is exactly right now. Indeed even the creature we see in the mirror in the morning, bedraggled and tepid, represents the culmination of a long line of evolutionary struggle. Each human represents the expression of successful genes, tested in the environment of deep time, improved upon over countless generations and through a multitude of challenging environmental contexts; the genes that survived the ice ages, survived diseases and natural cycles on the surface of the Earth – collections of matter bound up into “good enough” packages that “made it” through the task of reproducing and raising their young so that they could in turn, reproduce. Each creature in this grand view of life is the pinnacle of what it takes to be successful on the surface of the planet right now. And right now, even on the scale of a single human life, is an iota of time in the stupendously larger time frame of geological time.
The more you can conceive of deep time the greater the impact of realizing how wonderful life is – that each reproduction represents another experiment in the melee of genetic survival.
When we eventually venture out of the protective cradle that is our planetary atmosphere and its protective magnetic field, and into the potently hostile environment of space, our journey to other worlds will be filled with considerable hazard, and the drama of our genetic struggle will be played out on the monstrous scale of galactic time.