This thing
all things devours;
Birds, beasts, trees, flowers;
Gnaws iron,
bites steel;
Grinds hard stones to meal;
Slays king, ruins
town,
And beats mountain down.
Bilbo Baggins and Gollum, while struggling for dominance against one another, entered into an exchange of riddles in Gollum's cave, as recounted in the fifth chapter of The Hobbit. The answer to this one is “time.” The riddle underscores a particular distinction about what we consider as the continued progress of existence – that is, time may stiill best be defined in a question intentionally phrased to require ingenuity.
Time alludes any simple definition; however, people do try to make time seem like a concept with an distinct meaning – either a simple one or one so complicated literally no one can understand it.
For example, on the simple side, in 1919 within a story titled “The Girl in the Golden Atom,” Ray Cummings used this humorous but thought-provoking definition …
“How would you describe time?”
The Big Business Man smiled. “Time,” he said, “is what keeps everything from happening at once.”
“Very clever,” said the Chemist, laughing.
Don't laugh too hard until you think about this idea. You may wish to come back to this oversimplified explanation after you read this blog entry because if you want to get your feet wet in the great pool of trying to understand time, you should be prepared to bend your perceptions. “This stuff is hard” as I have heard many a high school student say about nearly anything requiring operations of the cerebrum.
Time appears to be more puzzling than space because it seems to flow or pass or else people seem to advance through it. But the passage or advance seems to be unintelligible. But do we actually experience the flow of time?
Theorizing is motivated by our subjective experience of the forward flow of time. That means our reliance on what we think we experience as the flow of time goes so deep that some philosophers take it for a self-evident axiom. And, if the flow of time is inherent to experience, then is “timeless experience” an oxymoron? If the past and the future are not actually experienced in the past and future, how can there be an experiential flow of time? Where is experiential time flowing from and into? The problem is that we then construe from this, that there is an experiential flow of time.
It's getting deep, isn't it? Are you ready for an explanation about the actual flow of time that requires experience? Here you go …
“Such a conclusion is as unjustifiable as to construe, purely from seeing the mountains ahead and the valley behind while you sit by the roadside, that you are moving on the road. You aren’t; you are simply taking account of your relative position on it. You have no more experiential reason to believe that time flows than that space flows while you sit quietly by the roadside.
“You may claim that, whereas the desert road scenario is static, lacking action, you actually did brush your teeth earlier. So time definitely flowed from then to now; or did it?
“All you have supporting belief that it did is your memory of having brushed your teeth, which you experience now. All you ever have is the present experiential snapshot. Even the notion of a previous or subsequent snapshot is—insofar as you can know from experience—merely a memory or expectation within the present snapshot. The flow from snapshot to snapshot is a story you tell yourself, irresistibly compelling as it may be. Neuroscience itself suggests that this flow is indeed a cognitive construct …
“The ostensible experience of temporal flow is thus an illusion. All we ever actually experience is the present snapshot, which entails a timescape of memories and imaginings analogous to the landscape of valley and mountains. Everything else is a story.”
(Bernardo Kastrup. “Do We Actually Experience the Flow of Time?” Scientific American. November 14, 2018.)
If you have my limited range of understanding, right about now you are questioning whether you even really exist. Or have you considered the problem of solipsism? Solipsism technically, is an extreme form of skepticism, at once utterly nuts and irrefutable. It holds that you are the only conscious being in existence. The cosmos sprang into existence when you became able to perceive things, and it will vanish when you die. As crazy as this proposition seems, it rests on a brute fact: each of us is sealed in an impermeable prison cell of subjective awareness.
But that's a problem for another blog entry. Let's get on with the definition of time. Exploring the thoughts of philosophers and religion could help.
In Britannica, Physicist and Astronomer William Markowitz tells us the human experience and observation of time has been variously interpreted. Parmenides, an Eleatic philosopher (6th–5th century bce) and Zeno, his fellow townsman and disciple, held that change is logically inconceivable and that logic is a surer indicator of reality than experience; thus, despite appearances, reality is unitary and motionless. In this view, time is an illusion.
The “illusoriness” of the world that “flows” in time is also to be found in some Indian philosophy. The Buddha and, among the Greeks, Plato and Plotinus – all held that life in the time flow, though not wholly illusory, is at best a low-grade condition by comparison, respectively, with the Buddhist nirvana (in which desires are extinguished) and with the Platonic realm of forms – i.e., of incorporeal timeless exemplars, of which phenomena in the time flow are imperfect and ephemeral copies.
(William Markowitz. “Time: physics.” Britannica. 2021.)
Are you confused yet? I am. And, we have some pretty good company in our state of bewilderment – one of the greatest mathematicians, physicists, and most influential scientists of all time, a key figure in the Enlightenment – Sir Isaac Newton (1643-1727).
In Philosophiæ Naturalis Principia Mathematica (1687) Newton famously declared “I do not define time.” Unlike relative time, Sir Isaac Newton believed absolute time was imperceptible and could only be understood mathematically. According to Newton, humans are only capable of perceiving relative time, which is a measurement of perceivable objects in motion (like the Moon or Sun). From these movements, we infer the passage of time.
In fact, it has become increasingly clear that when we speak of time in physics, what we really mean is a measurement read from a clock. So, what exactly constitutes a clock in physics?
OK, a lot of knowledge has come through the years since Newton considered the enigma of time. So, science should help us determine the true meaning of time. Right?
Physics is the only science that explicitly studies time, but even physicists agree that time is one of the most difficult properties of our universe to understand. In the most modern and complex physical models, though, time is usually considered to be an ontologically “basic” or primary concept, and not made up of, or dependent on, anything else.
Physics equations work equally well whether time is moving forward into the future (positive time) or backward into the past (negative time.) However, time in the natural world has one direction, called the arrow of time. The question of why time is irreversible is one of the biggest unresolved questions in science.
Much of this is based on Einstein's theory of relativity. In the Special Theory of Relativity, Einstein determined that time is relative—in other words, the rate at which time passes depends on your frame of reference. Yet, he once said:
“People like us who believe in physics know that the distinction between past, present and future is only a stubbornly persistent illusion. Time, in other words, is an illusion. Many physicists since have shared this view, that true reality is timeless.”
(Ira Flatow. “Resetting the Theory of Time.” NPR. May 17, 2013.)
Damn, Einstein didn't even know the answer. I discovered that many physicists since have shared this view, that true reality is timeless.
One explanation involving physics is that the natural world follows the laws of thermodynamics. The second law of thermodynamics states that within a closed system, the entropy of the system remains constant or increases. If the universe is considered to be a closed system, its entropy (degree of disorder) can never decrease. In other words, the universe cannot return to exactly the same state in which it was at an earlier point. Time cannot move backward.
So, can we be certain that this thing called time exists? Is there any way to test that? And if time is real, what does that say about our past and future?
It appears that the laws of nature – as we know them now – are not eternal truths. Consider that new information on black holes and neutron stars has recently emerged to challenge these so-called “truths.” So, many speculations, theories, and prediction are currently holding up, but they could be falsified at any moment, which is good because that means real science is at work
“Things” change and evolve. So does our understanding about time.
In his book Time Reborn: From the Crisis in Physics to the Future of the Universe, theoretical physicist Lee Smolin says …
“Well, what I mean when I say that time is real is that everything which is real and everything which is true is real or true in a moment, which is one of a succession of moments. That's what we experience, Ira. And the question is: Is that the structure of nature? Does nature exist in a series of moments, one after the other? Is that what's really real about the world? Or is that, as Einstein said, an illusion, and there is some timeless picture which is the truer picture?
“ … Certainly the laws of nature, even if they're changing, change only occasionally or change very slowly. So within limited regions of space and time, which are quite enough for everything we'd want to do on Earth, as well as a lot of astronomy and astrophysics, we can use the laws of nature to predict the future.
“But I don't believe we could use the laws of nature to predict the future arbitrarily or infinitely far in the future. And I also am playing with ideas, these are also unproven ideas, that may be in quantum mechanical systems where the future is uncertain anyway. We could set up a system in the laboratory to develop new rules, new laws.”
(Ira Flatow. “Resetting the Theory of Time.” NPR. May 17, 2013.)
Therefore, many scientists are urging us to question the very laws of nature that we know as indisputable facts. It seems that change is the only inevitability. And, who knows what change will bring? “Truth” in its different domains – in mathematics, in ethics, in religion, in philosophy – is a slippery concept, seemingly always evolving … you guessed it … evolving “in time.”
Do you need some heavy duty research to back up that our concepts of time may be totally wrong? Then, you're going to love this study because it uses the simple, everyday analogy of brushing your teeth.
A team of physicists at the Universities of Bristol, Vienna, the Balearic Islands and the Institute for Quantum Optics and Quantum Information (IQOQI-Vienna) has shown how quantum systems can simultaneously evolve along two opposite time arrows – both forward and backward in time.
The study necessitates a rethink of how the flow of time is understood and represented in contexts where quantum laws play a crucial role.Dr. Giulia Rubino from the University of Bristol's Quantum Engineering Technology Labs (QET labs) and lead-author of the publication, said:
"If a phenomenon produces a large amount of entropy, observing its time-reversal is so improbable as to become essentially impossible. However, when the entropy produced is small enough, there is a non-negligible probability of seeing the time-reversal of a phenomenon occur naturally.
"We can take the sequence of things we do in our morning routine as an example. If we were shown our toothpaste moving from the toothbrush back into its tube, we would be in no doubt it was a rewinded recording of our day. However, if we squeezed the tube gently so only a small part of the toothpaste came out, it would not be so unlikely to observe it re-entering the tube, sucked in by the tube's decompression …
"Extending this principle to time's arrows, it results that quantum systems evolving in one or the other temporal direction (the toothpaste coming out of or going back into the tube), can also find themselves evolving simultaneously along both temporal directions.
"Although this idea seems rather nonsensical when applied to our day-to-day experience, at its most fundamental level, the laws of the universe are based on quantum-mechanical principles. This begs the question of why we never encounter these superpositions of time flows in nature," said Dr. Rubino.
(Rubino, G., Manzano, G. & Brukner, Č. Quantum superposition of thermodynamic evolutions with opposing time’s arrows. Commun Phys 4, 251. 2021).
To the layman, this suggests that time can move forward and backward in temporal directions at the same time. If true, the study shows “we need to rethink the way we represent this quantity in all those contexts where quantum laws play a crucial role."
Tell that to ancient Persian poet Omar Khayyam’s whose musings on the visceral difference between what has gone and what is yet to come represent some of my favorite lines:
“The moving finger writes; and having writ, moves on: Nor all thy piety nor wit shall lure it back to cancel half a line, nor all thy tears wash out a word of it.”
– Omar Khayyam
I'm pretty sure this entry gives you clarity about the definition of time. Yeah, I guess. I hope you believe me – my research into the subject was well-intentioned … but, admittedly its lacking for any concrete meaning. What is time? Let me summarize for your easy digestion:
1. Your concept of time depends upon your own experience.
2. The illusion of time is indefinable … at least right now.
3. The laws of nature probably don't apply to time, and
4. What is “real” and “true” depends upon your questionable reality of existence.
Class dismissed. Spend your indefinable, highly questionable time wisely. Remember, boys and girls: “Lost time is never found again” and “Time is money.” Well, unless you live in a universe that recognizes the existence of two directions of time at once.
From To Think of Time
Walt Whitman - 1819-1892
To think of time—of all that retrospection!
To think of today, and the ages continued henceforward!
Have you guess'd you yourself would not continue?
Have you dreaded these earth-beetles?
Have you fear'd the future would be nothing to you?
Is today nothing? Is the beginningless past nothing?
If the future is nothing, they are just as surely nothing.
To think that the sun rose in the east! that men and women
were flexible, real, alive! that everything was alive!
To think that you and I did not see, feel, think, nor bear our
part!
To think that we are now here, and bear our part!
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