Showing posts with label Rate of Change. Show all posts
Showing posts with label Rate of Change. Show all posts

Friday, April 26, 2013

Was Time Created?

Is it possible to create time? If you accept the modern cosmological paradigm that’s exactly what happened 13.7 billion years ago. If you accept that, was the creation of time a once only creation or is the creation of time occurring even as you read this? Or, is the whole idea of literally creating time something only those smoking the good stuff could conceive of, while those of a less befuddled mind view as total bovine fertilizer? It’s the latter IMHO, or should be.

According to the standard model of modern cosmology, the Big Bang event 13.7 billion years ago created both space and time. Exactly what the recipe was isn’t given, but there was this act of creation nonetheless. Again, the standard model gives a scenario that even after the Big Bang event, right up to the present time (and presumably beyond our present time) space is still be created (out of nothing) and thus to make room for all this additional space, space itself has to expand (into what isn’t stipulated) and thus we have the popular phrase that we exist in an “expanding universe”.

But if space itself is expanding, then space is a thing, and things cannot be created out of nothing which is what those advocating an expanding space are, well, advocating.

I have elsewhere examined this issue of expanding space and found it to be IMHO utter claptrap. That’s because the concept of expanding space treats space, as noted above, as if space were a thing. Space is not a thing anymore than society, atheism, Wednesday or velocity is a thing; or beauty. Some thing maybe beautiful, but beauty is not a thing.

Now what about time? The alleged creation of time, unlike that of space, seems to have been a one-off happening at that Big Bang event – or is it? Was time, 13.7 billion years ago, created for all time, unlike space, or is the creation of time an ongoing process?

Time only seems to exist up to and including this very moment – right ‘now’. One second from now is in the future and future time does not yet exist. So is time constantly being created in order for there to be a future?  If so, how is it being done, or again, what’s the recipe for creating or cooking up a batch of time? There can’t be a bona fide recipe; otherwise some nerdy geek could create a batch of time at the same time, or within time, which already exists! That concept of creating a bubble of time within existing time should make your head ache!

But relax, there’s no need for the aspirin. There has not been one nanosecond of time created by all the humans who ever were and are (and are likely to be), nor by any of humanity’s machines or devices. No theoretical physicist has ever claimed for example that the Large Hadron Collider could create time, even though it’s supposed to come as close as possible to creating the sort of energies though present at the Big Bang event. Tis a pity actually since many of us feel at times as if there’s not enough time in the day (week, month, or year) to accomplish everything. So wouldn’t it be nice if you could create a bit of extra time on the sly and have a 25 hour day or an eight day week.  Sadly, that’s to be realized only in your dreams (or science fiction books and films).  

The flipside that one second from now is in the future and future time does not yet exist, is what happened to the time that existed just one second ago?  It’s gone. The only record of what happened one second ago rests in your memory or in some recorded device, natural or artificial, all of which only exists or is accessible in the current now. You might remember an event from five years ago, but you remember it ‘now’. A fossil might be evidence of a previous time, but that evidence only exists for your consideration ‘now’. A newsreel film might document an event that happened decades ago, but when you view it you see it ‘now’. When you look at the stars, you see their starlight that was emitted years before, but you see it ‘now’.

It would seem that the only bona fide reality time has is ‘now’. Past time is no longer tangible; future time is yet to be tangible. There’s something very profound about ‘now’ – it’s only in the ‘now’ that things change, and of course change is what gives the concept of time meaning.

But let’s suppose that ‘in the beginning’ time was created ‘in the beginning’. There was a slice of time created at the alpha point – that “now” that gives time ‘reality’ that from the beginning onwards moves forward (in time) until it reaches the omega point. Or, perhaps there was a “now” slice of time created at the alpha point, but that slice stays put while reality moves past it until the omega point is reached. Think of a factory line where there is a row of gizmos (reality) and a worker (time) walks on up the line from gizmo to gizmo and attaches a doohickie to each gizmo in turn from alpha to omega. Or, the worker (time) stands still while a conveyor belt with the gizmos (reality) on it rolls past the worker from alpha to omega while he attaches to each a doohickie in turn.

However, a slice of time is awkward if there’s a different ‘now’ occurrence for different people as viewed by different people. That’s actually a consequence of Einstein’s Special Relativity (see further below).

Why postulate a ‘slice’ of time? Well, as already pointed out, time has no existence in the past and no existence in the future. There’s only that slice of ‘now’ time. How thin is that slice of ‘now’ time? How short is that duration of ‘now’ time? Well there is a concept of the shortest possible interval of time with the caveat that nothing can actually happen in any sense of the term meaningful in any shorter interval of time. Any interval of time can be infinitely subdivided, but there does come a point where nothing of substance can happen if the interval is too short. How short is short? Let’s just say the number of shortest yet meaningful time units that would fit into one traditional second of time vastly, vastly, vastly outnumbers the entire human population past and present. When we say “short”, we really, really, really mean “short”.

But if time were created for the entire duration it would be required for, then that implies some foresight or foreknowledge on the part of the process that created time (or the cook that owns the recipe book). Speaking of the cook, it’s like the cook knowing in advance how big a turkey to buy and prepare for Thanksgiving dinner by knowing in advance how many guests will be present.

If time can be created even if only as a slice of time, then time can cease to be created.

If time were to stop being created, we’d never know since nothing would or could change (which is what time measures – rate of change). We only perceive time because things change from second to second; minute to minute; hour to hour, etc. If time stopped, our hearts would stop in mid-beat, clocks wouldn’t tick, boiling water would stop in mid-boil, and photons on route from the Sun to your eyeball would freeze in mid-space. Presumably if this had ever happened, you’d be none the wiser since that would imply that time was rebooted.

Another fly in the ointment is that while everyone perceives their personal rate of time flow at one second per second (and a second of time by the way is an artificial manmade unit of measurement), not everyone views everyone else’s time flow rate as being one second per second. The flow rate of time, as Einstein pointed out (Special Relativity) is relative. Further, depending on frame of reference, one can see Event A happen before Event B while someone else sees Event B happen before Event A, while a third body sees Event A and Event B happen simultaneously. That’s because it’s the speed of light that’s the physical constant. It does seem odd that in the beginning (assuming a beginning) it wasn’t time or space that was created as being a constant rather it was the speed of light. Actually that makes some sense since both time and space are not things, but light is a thing. However, it’s as if the speed of a batted or thrown baseball was always fixed and the dimensions of the ballpark and the playing field shape-shifted from second to second to accommodate the required outcome!

But adding Special Relativity to the creation of time equation just makes the creation of time recipe super complex. So let’s just drop the idea of time as a thing. Depending on point of view, events happen more or less quickly to others than you think is natural from your frame of reality. You just by force of habit translate that into time units, a habit you need to break. 

When it comes to the concept of time, it is second nature to suppose that no matter what starting or alpha point you presume, a question “what came before that?” is obvious even to blind Freddy. Therefore, it is way easier to adopt the philosophy that there was no alpha point (or omega point) – that time has always existed (and will always exist). Therefore, there was no need for time to be created.

If time wasn’t created, was there ever a first moment when time came to be? That would be the case if (and that’s going to be a mighty bug if): 1) time was an intrinsic property of matter and energy, and 2) if matter and energy were created from scratch. Leaving Point 2 aside for another day, time is not a property of matter and energy*. It’s not difficult to imagine a universe with just one electron in it. As far as that electron is concerned there is no time since there is no change to the state of that universe since there is no change, cannot be any change, to the state of the sole inhabitant of that universe – the one and only electron. Therefore time is not an intrinsic property of matter (and energy).

Finally, you cannot see, hear, taste, touch or smell time, nor can any mechanical instrument. You can say that time can be measured, but what are you actually measuring? What you are measuring are the changing properties of things you (or an instrument) can see, hear, etc. What about a clock? What changes on a clock? Well the minute hand moves from 4 to 5 or on a digital watch the reading changes from 4 to 5. There is a change in the properties of the clock or the watch that you can see or hear. You just label that change in the clock’s properties, time. Your label of time is a concept, a human concept. 

All concepts, like society or beauty, are created, but in the minds of living things, and not just by human beings either since one can imagine non-humans appreciating beauty. No doubt my cats view a full food bowl as something of great beauty! Of course that means in another sense that time has been created, but by humans (and maybe by other animals) for humans. Just like mathematical concepts (more human inventions) help us come to terms with, or help us explain, reality, ditto our artificially constructed concept of time. You certainly don’t hear cosmologists talk about the Big Bang creating concepts like mathematics, society, Wednesday, birthdays, beauty, atheism or velocity. Concepts like these have no tangibility – you can’t weigh them or put them under a microscope.

Conclusion: Time is the most mysterious facet of the cosmos and of your daily life you ever have to come to terms with, though most people don’t bother. But it needn’t be if you stop thinking of time as a thing and view time as a concept, like say your birthday. Unfortunately, way too many cosmologists imply that time is a thing and that the thing we call time was literally created. It’s very easy to say that time was created at the Big Bang event and those hundreds of cosmologists say exactly that. But it’s quite another thing to produce the recipe for how that was accomplished, and on that point these same cosmologists are very strangely silent on the matter. Extraordinary claims (like stating that time was created) require extraordinary evidence – one of those mantras the scientific community love to hurl at those advocating anything they call pseudoscience – but none is given by those very same cosmologists. 

What the Big Bang event did do was set in train all those laws, principles and relationships that govern the cosmos and govern change in the cosmos, which is what our concept of time measures.

So, was time created ‘in the beginning’ – no; ‘once upon a time – that doesn’t work either. No matter how you slice and dice things, the idea that time can be created, like space, is also IMHO utter claptrap. That’s because the concept of creating time treats time as if time were also a thing. Time is no more a thing anymore than space is a thing. But if time itself is being created, then time is a thing, and again things cannot be created out of nothing which is what those advocating the creation of time are, well, advocating.

The easiest way to deal with the concept of time is that that’s exactly what time is – a concept, an abstraction, but not a thing. If time isn’t a thing then time could not be created. If time isn’t a thing, then time travel isn’t possible. You can travel in a thing (i.e. – a car), not in a concept.


*If you consult any science reference book on the fundamental properties of matter and energy, time will not be listed, though things like mass and charge and spin, etc. will be.

Wednesday, November 7, 2012

The Physics and Philosophy of Time: Part One

“What is time?” That is a question that has been pondered and debated for probably thousands of years by some of the finest philosophical and scientific minds ever produced, without any definitive resolution. So, I’m NOT going to pretend that this is THE ANSWER – the be all and end all to the question. It’s some of my thoughts, which hopefully are as valid as anyone else’s!

What Is Time? It has been said that time is just Nature’s way of preventing everything from happening at once! But the word ‘happening’ is significant because if something happens, something changes. To my way of thinking, time is synonymous with change; time is a measurement of change; change gives the concept of time tangible meaning. If nothing ever changed, if nothing ever happened, it would be meaningless to talk about time. Time is just our informal perception or more formal measurement of rate-of-change. Rates-of-change vary depending on how fast you travel relative to some other frame of reference (the General Theory of Relativity) so the time intervals that measure that rate-of-change vary accordingly. I also can’t help but wonder whether, speaking of things relative, whether one could insist on a constant rate-of-change that’s made constant because your rate-of-time varies, or the more common view from day-to-day experience that rate-of-time is constant but rate-of-change varies.

It’s not difficult to understand why you are not aware of time passing when you sleep. It’s because you’re not aware or cognoscente of anything changing while you’re asleep. In fact, sleep is a way of achieving time travel. You go to sleep at 11 pm. Next thing you know its 7 am and you’ve traveled eight hours into the future seemingly instantly!

Thusly, I conclude that time doesn’t have a separate reality. I mean you can’t weigh time, it has no mass, it has no charge or energy, it isn’t a force and has no particle associated with it, you can’t put time to any physical use, nor can you manipulate time. You certainly can’t bottle and sell it! It’s about as intangible a something as the Universe allows.

Did time exist before there was anyone around to put a label to it? I mean in a pre-life era, change certainly took place – rocks eroded, the tides ebbed and flowed. But was there time? I suggest the answer is ‘no’ in that it takes a certain level of intellect to recognize change or rate-of-change. A rock doesn’t perceive time, nor does the beach upon which the tides act. The changes are physically real enough, but it takes something as complex as a living organism (not of necessity just a human organism) to perceive and understand change, and rate-of-change, which – human beings – for lack of a better word, we call it all happening (i.e. rate-of-change) as a concept called ‘time’.

By analogy, there is the oft quoted puzzle of there being this tree in a forest which falls. Does the falling/fallen tree produce any sound if no one (meaning humans) is around to hear it? (Of course there would be animals like bears, deer, possums, birds, etc. that would hear the sound, but let’s suppose that the forest contains just plants which I assume we can agree on, can’t hear. Now regardless of whether any animals are around or not, the falling tree will produce vibrations in the air (usually air, but vibrations can be equally transmitted in a liquid or solid medium). But vibrating air isn’t by itself sound. Sound is the perception (and possible interpretation) of those vibrations, and that takes a detection device and software (ears and a brain). So, there is no sound without ears and a brain, although the vibrating air is quite real regardless.

Time too, by way of my analogy, is akin to sound; change or rate-of-change is akin to the vibrating air. The former two (time and sound) are perceptions of physical events; the latter two (change and vibrating air) are the real physical events.

You’d think that therefore time wouldn’t exist in a vacuum or at a temperature of absolute zero, as how could anything change in a vacuum which contains nothing or at absolute zero when all motion ceases? Ah, enter the weird and wonderful world of quantum physics and discover that quantum activity, happenings, change, motion, etc. exists even in an apparent perfect vacuum and even at as close to absolute zero as makes no odds. In quantum physics, there’s no possibility of a perfect vacuum; absolute zero is only abstract and can’t ever be actually achieved. Therefore, time always exists as well. There seems to be no way to ever shut down quantum activity and achieving a perfect vacuum and/or absolute zero, so we’re in no danger of ever having our perception of time cease.

The shortest (quantum) unit of time possible is just that interval below which no possible change can happen. In other words, even the quickest ever possible change one can imagine takes an absolute minimum amount of time.

Change also implies there must be causality – there must be a cause that produces an effect, or in other words, something is affected by something else that occurred previously. Going from cause to effect implies a change and a time interval must have taken place into which that change fits. This introduces the commonly used phrase ‘arrow of time’. If time is our perception of change, then what is the ‘arrow of time’? Methinks it’s the reality that on the macro scale at least change happens only in one direction – cause precedes effect; effect follows cause, and that’s change. Examples of such one way cause and effect change include dropping the china cup and it breaks. A broken cup does assemble itself and then leap off the floor into your hand. Humans tend to be conceived, get born, grow up and age. Hair turns gray (or falls out), you get wrinkles and liver spots, and you die. You don’t rise from the grave, re-animate, and age backwards towards childhood and pop back into the womb! A hot cup of coffee cools off to room temperature. A cold cup of coffee doesn’t heat up by itself; even if there’s potential energy enough in the environment (air molecules flying around) to theoretically heat it up.  In other words, you can’t unscramble (or un-boil) an egg. 

Present Time: The Concept of ‘Now’: Does the present actually exist? We speak of it was if it does. But does it? Now I’m sure there’s no debating that there is a past, and that there will be a future. I’m sure there’s no debating that what we’d call five years ago exists in the past; five years on from when you read this is clearly the future. What about five months ago, or ahead?  What about five days or five hours or five seconds? Is half a second ago the past? Is half a second hence the future? Of course it is. In fact, I suggest you can split units of time ever shorter and shorter, but still admit that ‘ago’ means past; hence means future, even if 0.000005 of a second ago really is past, and 0.000005 of a second hence is the future. So where comes the ‘now’ or the present?

While there is a past, and will be a future, there really does exist a present. There apparently is such a thing as the shortest interval of time and nothing shorter can exist in reality. That shortest interval of time is known as Planck-Wheeler time, below which time as we know it ceases to exist. It’s about 10 to the minus 43rd of a second. That’s how long your present lasts for! One Planck-Wheeler time unit behind you is now forever locked in as part of your unalterable past. One Planck-Wheeler time unit ahead, is still part of your malleable (free will?) future.

Even without resorting to quite such a tiny present, physics logic suggests that you really are an isolated individual that cannot share the present with the rest of the world. Lets imagine this couple, say we call them Clive and Jane, sitting down for their evening meal. Clive says to Jane, “pass the salt please darling”. Now Clive utters that phrase in his present and Jane hears it in her present. But both presents aren’t simultaneous. When Jane hears it in her present, it’s simultaneously Clive’s past because it takes time for sound to travel from voice to ear (and light from mouth to eye). Actually, when Jane hears the word “salt”, “pass the” is already in her past while “please darling” is still in her future. In other words, Clive and Jane can’t ever share the same present even though both pass through identical simultaneously now’s.

Here’s a form of time travel. When Jane looks in a mirror, the image she sees in her present is actually of herself from her past – an ever so slightly younger version of herself because it takes an interval of time for the light to be reflected off Jane, onto the mirror, reflected off that, and back to Jane’s eyes.

In summary, nothing you see or hear has the exact same reality that you perceive in your present because there has been a time lag and things change over time – even incredibly short intervals of time. A common example is looking at a distant star. The star you see in you’re here and now isn’t the same star that exists in that same here and now. You’re looking at a star, which, for all you know, just may no longer exist!

Of course you do live your entire life in the actual ‘now’ – you certainly don’t literally live in any part of your past, nor your future. Your life, your lifetime of ‘now’, is a string of Planck-Wheeler time units.

Saturday, September 29, 2012

It’s About Time – For a Change: Part One

Introduction: The real nature of what we call ‘time’ is one of the Big Questions. It’s been debated ever since humans evolved thought and language. That puzzlement remains true to the average person today, although ‘time’ has become the professional subject or province of philosophers, metaphysicists, and theoretical physicists, not to forget many a science fiction author! Here’s my two cents worth – ‘time’ is an illusion!

What Is Time? Time is, IMHO, an illusion. Time has no real independent existence – it can’t stand by itself. If you removed all the matter and energy from the Universe, would there be left anything we could address as time? Time is just our way of keeping track of, and measuring rate of change in matter and/or energy. If nothing ever changed it would be nonsense to talk about time. The flow of time; the arrow of time; is just the flow of macro things changing. If everything were somehow ‘frozen in time’ – like a single frame from a film – then there is no actual time that can be discussed or measured. So we don’t in any sense measure something that is time, we measure rate of change and call that time.

Actually you measure rate of change by another rate of change. For example, the rate of change from birth to death is usually measured by the rate of change in position of the Earth orbiting the Sun (years and fractions of years) and rate of change of position of the Earth rotating around on its axis (days and fractions of days). Another example: The rate of change between the beginning of your lunch hour and the ending of your lunch hour is usually measured by the rate of change of the hands of a clock (sixty 360 degree sweeps of the minute hand or a 30 degrees clockwise change in the hour hand) or the rate of change in the numbers on your digital watch, say from 1:00 to 2:00. Translated, a variable or uncertain rate of change (lifespan; length of a lunch ‘hour’) is usually measured by a standard, invariable, predictable rate of change.

Now rate of change is affected by gravity – a function of mass – the greater the mass the greater the gravity and the slower things change from A to B in that gravitational field, but that slowness is only relative to someone else also measuring A to B but who is in a lesser gravitational field. A clock at the top of a tall building (lesser gravity being further from Earth’s centre) ticks at a faster rate than an identical clock at street level (which has higher gravity due to being closer to Earth’s centre). Rate of change is also affected by velocity. The faster you go, the slower things change from A to B, again however it’s relative to someone else also measuring A to B but who is moving at a lower velocity relative to you. That’s why it’s the theory of relativity! The standard example is the twin paradox – if your identical twin zooms off in a spaceship at extreme velocities to the distant stars, stops, reverses direction, and returns at that high rate of speed to Planet Earth, and to you, you’ll find your twin has aged to a far lesser degree than you. You now have grey hair and wrinkles; your interstellar travelling twin is still in her youthful prime of life.

Time vs. Time Travel: I’ll poor water on this fire at the outset by stating again that time is but an illusion. Time doesn’t exist; therefore time travel isn’t possible. Time is but a label, like your own name is but a label, and has no more reality than the label ‘Wednesday’. We just arbitrarily call every 7th ‘day’ Wednesday, but you can no more hold Wednesday in your hands and you can time. Time, repeating myself, has no independent reality. You can’t assign any physical properties to the concept. I mean time isn’t a solid, it isn’t a liquid, and it isn’t a gas. Time has no size, weight, colour, texture, density, it doesn’t vibrate or have a wavelength, ditto no odour or flavour, it has no temperature or pressure, it doesn’t consist of any known combination of known forces and/or elementary particles, it corresponds to no known element or compound. You can’t pour time into a bottle and store it; you can’t confine time in a force field or in a prison cell or trap it on a piece of sticky fly paper. Therefore, if time has no substance, one can not actually travel through time.

What we perceive as ‘time’ is, again repeating myself, nothing but change – change in our environment; in our natural world; in our mechanical devices; and even in ourselves and associated companions (animal and human). Repeat – time is but an illusion. Change is real (cause and effect) since it involves forces and particles; energy and matter, the sorts of things that when you kick them, they kick back. We measure ‘time’ by the rate things change; rate of change is what we call ‘time’. Repeat - it’s the change (in something) that is real. 

Now on the macro scale, that is scales we interact with on a day-to-day basis, change appears to all intents and purposes to go one way (usually from a state or high order to a state of disorder) and so we view time as flowing from past to present to future – in one direction; order to disorder – past to present to future. But change in just one direction (order to disorder – past to present to future) is ultimately a function of numbers and probability. The simple illustration is to introduce a drop of ink into a bowl of water. That’s a high order situation. Now left to itself, there will be a change. The ink will disperse throughout the bowl of water. That’s a state of disorder. If a disordered uniform mix of ink and water separated all by itself into a drop of pure ink and a bowl of pure water (high order), that too is change, but we would interpret or view such an event as going backwards in time. If you viewed such a happening on film, you’d immediately conclude the film was being run backwards.

There’s a far greater probability for individual ink particles to spread out throughout a large volume than to come together in a small space. There’s lots of pathways to spread out; far fewer pathways to come together. But at the micro level, the level at which those individual ink particles do their thing, they don’t care where in the bowl of water they are. They are just as ‘happy’ to be all together as a drop of ink, as dispersed and diluted. If they do come together as a drop of ink from a dispersed/diluted state, that’s statistically unlikely, but such an event violates no laws of physics. It would be going from a state of maximum disorder to a highly ordered state; or, from an apparent future to present to past ordering. Such a change would appear for all practical purposes as apparent time travel – going backwards in time.

The catch – there’s always a catch – is while all those ink particles are defying statistical probability and undergoing apparent time-reversal, the rest of the cosmos is acting in a statistically normal way – going forward in ‘time’. So, perhaps we have a Universe where for 99.9999% of the time, 99.9999% of events within the Universe march to the beat of the standard past – present – future ordering of things. That is, in terms of change happening in a statistically probable way. While now and again tiny pockets of the Universe reverse direction, they do so at least just temporarily.  One can only defy statistically probability for only so long. So the ink particles come back together again as a drop of ink within a bowl of water – then what? They no doubt reverse direction again and proceed normally.

An analogy might be that while some individuals are winners while playing the slot machines (high order), the club still rakes in the profits from the vastly greater majority of (disordered) losers, and that no doubt the few highly ordered winners will eventually descend into a state of disorder and contribute ultimately to the club’s profit margin! It’s more statistically likely for a winner to become a loser than for a loser to become a winner.

Consider electrons. On average, any given electron has a very high probability of participating in a changing set of circumstances consistent with statistically probability. That is, the electron is moving forward in ‘time’. But if in those rare (loser to winner) occasions the changing set of circumstances goes against the grain of statistically probability, then we would view that electron as moving backwards in ‘time’. But there ultimately is no backwards or forwards in time, just change which statistically goes or moves in one general direction (order to disorder), but which can now and again, albeit briefly, go the reverse direction (disorder to order).

To belabour the point, what we call the past is change which has already happened; the present is change which is happening; the future is change that will happen.

To be continued…

Sunday, September 16, 2012

Time & Time Travel: Part One

WHAT IS TIME? ‘What is time?’ exactly is a question that has been pondered and debated for probably thousands of years by some of the finest minds ever produced, without any definitive resolution. So, I’m NOT going to pretend that this is THE ANSWER – the be all and end all to the question. It’s my thoughts, which hopefully are as valid as anyone else’s!

It has been said that time is just nature’s way of preventing everything from happening at once! But the word ‘happening’ is significant because if something happens, something changes. To my way of thinking, time is synonymous with change; time is a measurement of change; change gives the concept of time tangible meaning. If nothing ever changed, if nothing ever happened, it would be meaningless to talk about time. Time is just our informal perception or more formal measurement of rate of change. Rates of change vary depending on how fast you travel relative to some other frame of reference (Theory of Relativity) so the time intervals that measure that rate of change vary accordingly. I also can’t help but wonder whether, speaking of things relative, whether one could insist on a constant rate of change that’s made constant because your rate of time varies, or the more common view from day-to-day experience that rate of time is constant but rate of change varies.

It’s not difficult to understand why you are not aware of time passing when you sleep. It’s because you’re not aware or cognoscente of anything changing while you’re asleep. In fact, sleep is a way of achieving time travel. You go to sleep at 11 pm. Next thing you know its 7 am and you’ve traveled eight hours into the future seemingly instantly!

Thusly, I conclude that time doesn’t have a separate reality. I mean you can’t weigh time, it has no mass, it has no charge or energy, it isn’t a force and has no particle associated with it, you can’t put time to any physical use, nor can you manipulate time. You certainly can’t bottle and sell it! It’s about as intangible a something as the Universe allows.

Did time exist before there was anyone around to put a label to it? I mean in a pre-life era, change certainly took place – rocks eroded, the tides ebbed and flowed. But was there time? I suggest the answer is no in that it takes a certain level of intellect to recognize change or rate of change. A rock doesn’t perceive time, nor does the beach upon which the tides act. The changes are physically real enough, but it takes something as complex as a living organism (not of necessity just a human organism) to perceive and understand change, and rate of change, which – human beings – for lack of a better word we call it all happening in a concept called ‘time’.

By analogy, there is the oft quoted puzzle of there being this tree in a forest which falls. Does the falling/fallen tree produce any sound if no one (meaning humans) is around to hear it? (Of course there would be animals (bears, deer, possums, birds, etc.) that would hear the sound, but let’s suppose that the forest contains just plants which I assume we can agree on, can’t hear. Now regardless of whether any animals are around or not, the falling tree will produce vibrations in the air (usually air, but vibrations can be equally transmitted in a liquid or solid medium). But vibrating air isn’t by itself sound. Sound is the perception (and possible interpretation) of those vibrations, and that takes a detection device and software (ears and a brain). So, there is no sound without ears and a brain, although the vibrating air is quite real regardless.

Time, to by way of thinking, is akin to sound; change is akin to the vibrating air. The former two are perceptions of physical events; the latter two are the real physical events.

You’d think that therefore time wouldn’t exist in a vacuum or at a temperature of absolute zero, as how could anything change in a vacuum which contains nothing or at absolute zero when all motion ceases? Ah, enter the weird and wonderful world of quantum physics and discover that quantum activity, happenings, change, motion, etc. exists even in a perfect vacuum and even at absolute zero. Therefore, time exists as well. There seems to be no way to ever shut down quantum activity, so we’re in no danger of ever having our perception of time cease.

The shortest (quantum) unit of time possible is just that interval below which no possible change can happen. In other words, even the quickest ever possible change one can imagine takes an absolute minimum amount of time.

Change also implies there must be causality – there must be a cause that produces an effect, or in other words, something is affected by something else that occurred previously. Going from cause to effect implies a change and a time interval must have taken place into which that change fits. This introduces the commonly used phrase ‘arrow of time’. If time is our perception of change, then what is the ‘arrow of time’? Methinks it’s the reality that on the macro scale at least change happens only in one direction – cause precedes effect; effect follows cause, and that’s change. Examples of such one way cause and effect change include dropping the china cup and it breaks. A broken cup does assemble itself and then leap off the floor into your hand. Humans tend to be conceived, get born, grow up and age. Hair turns gray (or falls out), you get wrinkles and liver spots, and you die. You don’t rise from the grave, re-animate, and age backwards towards childhood and pop back into the womb! A hot cup of coffee cools off to room temperature. A cold cup of coffee doesn’t heat up by itself; even if there’s potential energy enough in the environment (air molecules flying around) to theoretically heat it up.  In other words, you can’t unscramble (or un-boil) an egg. 

Further readings about time:

Lockwood, Michael; The Labyrinth of Time: Introducing the Universe; Oxford University Press, Oxford; 2005:


PRESENT TIME: THE CONCEPT OF ‘NOW’: Does the present actually exist? We speak of it was if it does. But does it? Now I’m sure there’s no debating that there is a past, and that there will be a future. I’m sure there’s no debating that five years ago exists in the past; five years on from when you read this is clearly the future. What about five months ago, or ahead?  What about five days or five hours or five seconds? Is half a second ago the past? Is half a second hence the future? Of course it is. In fact, I suggest you can split units of time ever shorter and shorter, but still admit that ‘ago’ means past; hence means future, even if 0.000005 of a second ago really is past, and 0.000005 of a second hence is the future. So where comes the ‘now’ or the present?

While there is a past, and will be a future, there really does exist a present. There apparently is such a thing as the shortest interval of time and nothing shorter can exist in reality. That shortest interval of time is known as Planck-Wheeler time, below which time as we know it ceases to exist. It’s about 10 to the minus 43rd of a second. That’s how long your present lasts for! One Planck-Wheeler time unit behind you is now forever locked in as part of your unalterable past. One Planck-Wheeler time unit ahead, is still part of your malleable (free will?) future.

Even without resorting to quite such a tiny present, physics logic suggests that you really are an isolated individual that cannot share the present with the rest of the world. Lets imagine this couple, say we call them Clive and Jane, sitting down for their evening meal. Clive says to Jane, “pass the salt please darling”. Now Clive utters that phrase in his present and Jane hears it in her present. But both presents aren’t simultaneous. When Jane hears it in her present, it’s simultaneously Clive’s past because it takes time for sound to travel from voice to ear (and light from mouth to eye). Actually, when Jane hears the word “salt”, “pass the” is already in her past while “please darling” is still in her future. In other words, Clive and Jane can’t ever share the same present even though both pass through identical simultaneously now’s.

Here’s a form of time travel. When Jane looks in a mirror, the image she sees in her present is actually of herself from her past – an ever so slightly younger version of herself because it takes an interval of time for the light to be reflected off Jane, onto the mirror, reflected off that, and back to Jane’s eyes.

In summary, nothing you see or hear has the exact same reality that you perceive in your present because there has been a time lag and things change over time – even incredibly short intervals of time. A common example is looking at a distant star. The star you see in you’re here and now isn’t the same star that exists in that same here and now. You’re looking at a star, which, for all you know, just may no longer exist!

Of course you do live your entire life in the actual ‘now’ – you certainly don’t literally live in any part of your past nor your future. Your life, your lifetime of ‘now’, is a string of Planck-Wheeler time units.

To be continued…