For a majority of us, time is but an alternate term for what occurs between two random points on the clock. But, here is the gist: clocks – as claimed by scientists – do not measure time at all, but only our very own limited and conditioned impression of it. Time is a concept that we depend upon as a stronghold in the overall uncertainties of unpredictable world, the intangible thought on a thin wire of existing and enforced that mesmerized us ever since, and continues to do so.
What is philosophy’s stance on this…
Ever since the ancient Hindu scrolls and all the assembled philosophical wisdom of old India – the Vedas – a man has, consciously or subconsciously, felt the cyclic nature of universe that passes from one stage of creation to another, that of destruction, and back again, “to the eternal recurrence”. Back then, two millennia before Christ, a perhaps the most important prerequisite of the existence of time has been set – the change; as well as the crucial question of whether time can only be observed through changes.
The eastern vision of metaphysics is, oddly enough, the one closest to the contemporary paradigms of natural sciences of 20th and 21st century – in the sense of their common conclusions. One of the greatest dichotomies in the history of philosophy were concepts of linear versus the cyclical time. Historians of ancient Chine debated very thoroughly and analytically about the events of the past, which endowed their nation with a very unique and sharply defined linear sense of time. However, flourishing of Taoism has, in a big way, turned this linear view of the world upside down, towards the cyclical – which was very specifically evident in the rise and fall of the Chinese dynasties (a fun trivia: the Chinese used to call the universe “Yii-Chou” which literally translates as “space-time”. “Yii” refers to tridimensional space, whilst “Chou” acts as the fourth dimension with the series of successive changes – a concept staggeringly familiar to Einstein’s “space-time”!). With the appearance of Budhism, linear and cyclical time (also known to Mayas, Incas and Babylonians) was joined by another one: timelessness.
Within the proverbial cradle of European culture, Greece, a first true synthesis of philosophical and scientific thinking was taking place. The one who pioneered the speculation that time could be related to the movements of celestial bodies was Plato (who was credited for saying “Time is a moving picture of eternity.”), and it was already with Aristotle that time was defined as a “conglomerate of changes on the plane of before and after”. Antiphon, the sophist, in his fragmentary work “On truth” claims that “time is not reality, but a concept or a measure.” Generally speaking, the thinkers of ancient Hellas had a penchant for standpoint by which there was no beginning of the cosmos, ie. that the entire reality has a limitless past.
Traditional western notion of time as an absolute with finely determined measure units is a consequence of Judeo-Christian teaching that opposed (for obvious reasons) the cyclical tendencies of the European part of the Old World as well as doctrine of polytheistic religions and pagan cults. During the Middle Ages, God was considered to be the cause of all things, and with him, the inevitable end was inexorable. In the modern age, however, chiefly after the Age of Enlightement, the science begins to seek for others, more convincing explanations of arche (pre-cause) of the world. Besides, post-quantum era of physics in its transformation encompasses a hefty amount of eastern philosophical knowledge. Physicist Fritjof Capra published a book titled “The Tao of Physics” in 1975.
Monumental philosophical system of Immanuel Kant consisted of a time that was a priori intuition which allows us to comprehend the experience of sensations. The agent of creative evolution, Henry Bergson, held intuition and creativity as the essence and main component of lasting (durée).
What stands out with its attraction in modern era are ideas of John Ellis McTaggart, who pronounces the invention of time contradictory because only present time is real. He regards time as unreal because the differentiation of past, present and future is more essential for time itself than a fixed relation between previous and latter. What is particularly controversial is his notion that historical events are no different that made-up stories, due to the past being nothing but the memory of series of events that can be “colored” in many ways (emotionally, by being one-sided or uninformed…). Our memory constructs a delusion about the past, conscious perception of events produces the feeling of present moment, while the future is merely a mental construct made by patterns of past experiences. This is why time is thought to be a manifest concept, because it is a tool of our mind to makes sense out of world that is packed with changes.
The self-exposing conclusion is that the present, seemingly the most trustworthy dimension of time that we can rely on, is in fact the infinitesimally short-lived moment, simply a recording of a memory in a brain that we are mentally aware of. For example, if a person falls asleep and while being asleep completely misses a certain period of time or some happening, that event, de facto, never existed in his or her past, and therefore won’t exist in the past.
Philosopher of science, Craig Calendar (suitable name for the topic at hand) has established an altogether new and, quite frankly, genial notion of time, by dividing it into few types: our psychological impression of time progression, the measured time and biological time, thus making a non-biased comparation between absolutist view, by which time progression is independent of all changes in cosmos, and the relationist view which says that time itself is nothing but the change in cosmos.
…and what is science’s point of view
Without a trace of doubt the most unavoidable scientific figure in the last 100 years is still the amazing Albert Einstein. He has irretrievably transformed both space and our idea of time, making it relative and departing from Newtonian tradition of absolute time.
There is one man whose duty is to embark into most remote pits of time. His name is Ferenz Krausz and he is a quantum physicist who, in his laboratory in the Max Planck institute, measures the shortest temporal intervals ever observed – in quantum leaps of electrons in atoms. The interval between two leaps is about 100 quintillions of seconds (also known as attosecond). And to put this in some perspective – 100 attoseconds is to one second what one second is to 300 million years!
That what happens on such incomprehendable scales of intervals must have certain “strange” consequences regarding thought experiments whether time exists at all. This temporal dimension, the Planck scale, is the boundary area of known, “macro” physics and physics in which the scales are so small that space and time dissolve (Planck’s time is the smallest measurable unit of time – 10−43 seconds). When one contemplates this quantum reality, the only way to do that is to abandon the widespread concepts of time. Whatsmore, a certain majority of physicists considers their science to be heading towards describing universe as timeless – for it is believed that time below the Planck scale, on the most fundamental levels of physics, may not exist.
And what about the arrow of time? Why is time moving specifically towards the future, when all the known laws of physics would function just fine even if time went backwards? Time is a unidirectional process because the initial state of cosmos was a very condensed, very compact dot of energy, whose expansion (that began with the Big Bang) caused bigger complexity and smaller orderliness of the universe – in other words, the direction of time and the growth of entropy go hand in hand. Austrian physicist, Ludwig Bolzmann, has defined entropy in 1870 as the measure of a degree of order within a closed system. Of course, the human tendency to comprehend every system works in a way that we need to determine the initial and final conditions. And here’s the irony: this endeavor of ours, to describe the beginning and the end, is bothered by the fact that time is a continuum without end.
In that sense, time is not something that exists outside of cosmos. Newton argued that time was something absolute, mathematically true, that springs out of itself and flows no matter what. Einstein has proved that time is part of the fabric of cosmos. Seth Lloyd, MIT’s quantum engineer, quotes an anecdote during his visit to National Institute of Standards and Technologies in Boulder, where the atomic clock that standardizes time in the USA is located. On his remark that their clocks aren’t very precise, the local scientists responded with: “No, our clocks do not tell time. Time is determined by what our clocks measure. Because, we never see the time iself, only the clocks – that is, physical variables as functions of other physical variables. And then we present it as an evolution, a succession of things in time.” Carlo Rovelli, the theorist of time, claims that past and future are best explained by causality and our search for causes and consequences – but also reminds that we can glimpse only somewhat into past and future.
Sean Caroll, theoretical physicist, wonders why is the past different than future and why do we remember the past, and not the future (also, he deals with irreversibility of that process, that is why can the egg turn to omlette and not vice versa). He goes back to entropy, but with a delicate maneuver, asking: why was entropy low in the beginning, anyway? The most credible assumption is this is because our universe is expanding. Each universe that wouldn’t expand would reach maximum entropy and lose its arrow of time (small temperature variances are the proof that young universe had low entropy). The farthest past we know of, the singularity, was the inception of the time as we know it and the state of lowest entropy. If we could discover what came before singularity, we would also find out what preceded low entropy as well as is there, beside ours, another arrow of time, in some other universe, that may have been released in some other direction.
Yes, the entire time saga may appear to be equally confusing as fascinating, both as a philosophical play and the set of scientific theories. There may not be any other phenomena that could be looked upon under so many different lights, from so many different angles. Time is a subject that evades explanations with remarkable ease – and yet, those explanations keep on multiplying.
For P.U.L.S.E World: Andrej Vidović