This is one of the BIG questions. Actually it is two questions.

Concerning the first one, the short answer is - we don’t know. Leaving God out of it, we can say that no one we know does. And by ‘we’ I mean Mankind.

Certainly we are aware of time, and have been for millennia. We know how to measure it extremely accurately with atomic clocks. It’s a familiar variable in all sorts of equations from interest computation to business risk assessments. We finally have our calendars in agreement globally and our time divisions and dateline on Earth sorted. We are accurately measuring Sidereal Time. The physicists have time as a variable in their major theories of Special Relativity, General Relativity, Quantum Mechanics / Theory, Thermo-Dynamics, Entropy Theory and Information Entropy Theory.

So you might be under the illusion that we understand what time is, and that you’ve just been missing out somewhere because it’s a bit mathematically complicated and it’s got something to do with Quantum and Bosons and Super Colliders. You know a smart friend who bought Stephen Hawkin’s A Brief History of Time, but only got half way through it, so you haven’t actually tried to read it yourself.

Well, true as all that may be, the short answer remains that no one knows. That included Stephen Hawkins, which is not to say he didn’t have some interesting insights and things to say about it. A Brief History of Time is commonly described as the most half-read book in the world. However, even for those of us who read and understood it all, it didn’t really answer our questions concerning ‘What Time Is?’ any more than Newton or Einstein did. Both these geniuses contributed enormously to our understanding of physics, the universe and reality, but … at the end of it we still don’t really understand time. In fact, Einstein probably contributed more to our understanding of just how much we DON’T understand time than anyone else who has ever lived.

Time is one of the really BIG mysteries. It might even be the biggest, right up there with questions about existence itself.

So, no - Celestial Koan cannot tell you what time is either. However, since it’s a really big part of reality, CK has spent some of his own allotment of time on this planet looking into it. He plans to publish his own book on the subject one day, which he hopes will be better read AND comprehended than A Brief History of Time was. He also hopes it will be more informative.

Meantime, between this article and several others found and linked under this topic, I think we can give you some useful understanding of the nature of time, what it is, and what it isn’t. Perhaps more importantly still, you can gain an insight into what we don’t know about time, and why it is still such a great mystery.

As already mentioned ‘Time’ appears as a critical measurement / variable / dimension / factor or whatever in a number of major current scientific theories. These include both Special and General Relativity. They include various theories of Quantum Mechanics, including such things as String Theory. Time is treated as a fundamental universal factor in Newtonian Mechanics. Time distinguishes ‘states’ in Entropy Theory and Thermo Dynamics.

One of the problems is that each of these theories views Time somewhat differently. Possibly the biggest challenge in coming up with the Holy Grail of Science, a GUT (Grand Unified Theory) or TOE (Theory of Everything) is coming up with a Theory that treats Time in a way that makes sense for all the existing theories. For example, Entropy and Thermo-Dynamics equations are the only ones that give Time a clear direction, that is indicates that time can only flow from the past to the future, from the cause to the effect.

Relativity gives us a ‘rate’ of flow of time, as a consequence of tying all things to the velocity of light.

In Quantum Theory the equations work just as well with time going ‘backwards’ as ‘forwards’.

Quantum Theory does provide some important statements concerning the limits of accuracy to which it is possible to measure time (and position / mass etc.)

So now let’s address the second question - How can I understand it?

Well, if you genuinely are driven to wanting to understand ‘Time’ you should probably start by getting your head around all those theories.

Reading Stephen Hawking’s A Brief History of Time is probably a good starting point, and will help you understand the relationship between the hypothesised ‘Big Bang’ singularity and the ‘Beginning of Time.’ The short answer appears to be that ‘Time in this universe’ may have begun from a dimensional formation fractionally ‘after’ the singularity, and if you think that doesn’t make any sense - you are starting to understand the issue.

There are a number of alternative cosmological theories to the Big Bang version now, including ‘The Big Crunch’, and the ‘Oscillating Universe’ theories. Since ‘Inflation’ is causing problems concerning theories as to how far and fast and long the Universe is / will keep expanding, there’s plenty of uncertainty surrounding this.

Next - you need to wrap your head around information and particularly ‘Information Entropy’ and Maxwell’s Demon. This will also enable you to understand why people like Penrose and Hawking are concerned about what goes on at the boundary of a Black Hole, and whether the Universe is a ‘closed system’ or whether information is leaking out of (or into) the universe.

A particular problem for ‘Information Entropy’ is the question of why Entropy is so low at the beginning of the universe.

Once you’ve done all this you will understand what science and the physicists understand (and don’t understand) about time.

Move on to another branch of science - Psychology. Psychologists try and understand the problem of ‘Experiential Time.’ We all know that our personal conscious experience of time includes periods when time seems to fly, and when time seems to hang. Some things that happened twenty years ago are recalled in vivid detail, while things we did, saw, or said five minutes ago are almost impossible to recall. Memory, emotions, and observations become critical issues here. What are Engrams and how do we ‘remember things?’ Where do dreams fit into this? Could the Mandela Effect be real (look this topic up on Quora).

Time to briefly look at the science of ‘Comparative Linguistics’. How do languages handle ‘Time’, and how do they influence our thinking and intellectual models about time? For example, I know of only two of the thousands of languages on Earth that treat the Past (what we can and do know) as being ahead of us, and the future (which we can’t see and know) as being behind us. Most languages - like English, consider the Future to lie ahead of us, even though we can’t see into it. Example - “I’m looking forwards to a bright future.” Why? Some languages don’t even include verbs (Past and Future tenses).

It’s worth spending a little while considering the different scales of time. Briefly get your head around Astronomical Time (including the history of our sun and solar system), Geological Time (the structure and formation of the Earth as it is today, with continental plate tectonics etc.), Evolutionary Time (palaeontology, genetic drift, The History of Life on Earth and the fossil tree), Climate Sciences (formation of our oxygen atmosphere, temperature changes across the eons, ice ages etc.), down to how time is measured with atomic clocks and kept synchronised across the internet.

Now you are ready to start considering some of the serious philosophical issues of Time. The validity of cause and effect models. The ‘First Cause’ problem, which takes you back to the Singularity, the Information Entropy problem mentioned above, and right into the issues of Religion and Theology. Is there a creator god, a ‘First Mover / First Cause’, and all the rest of that? Is there any difference between saying ‘God Created’, and saying ‘There was an inexplicable Singularity’?

At this stage you will understand some of the following problems:

1. The Past appears to be defined, somewhat knowable and finite. We can’t change it. The Past leaves traces, including in our memories. The Future appears to be indeterminate, unknowable, and possibly infinite. Again, we can’t change it. The Present appears to be infinitely brief, possibly infinitely broad, and is the only tiny moment when anything can be changed.

2. We appear to make choices and decisions, but … do we? We don’t know how to program a computer Artificial Intelligence to do anything except make some combination of random choices and programmed decisions. It makes ‘decisions’, but not ‘Choices’. It has no ‘Free Will.’ Are we any different? How? How does Time, Free Will, and ‘Choice’ work? Does it?

3. We are never conscious of the Present. By the time we have processed the information from our senses into consciousness, what was the Present has already become the Past. So how do we act ‘in the Present’? Remember, we can’t change the Past, it’s already happened?

4. We can’t actually prove any of this yet. How do you design an experiment to prove that Effect does NOT always follow Cause? How can you prove that the Past canNOT be changed? How do you prove that the Future can NEVER be known?

At which point you will bump into issues of the three ‘P’s: Prophecy, Prescience, Prediction. Each has various theological, mystical, spiritual, para-psychological, and possibly even practical issues. Can some people predict or influence the future AT ALL? Can you prove that prophecy and prescience are NOT possible? Is there anything to Karma, Ghosts, Fate, Astrology, Synchronicity, etc. Careful study will suggest ‘Yes’, but it’s darn hard to pin down.

Which takes us to the issue that Time most certainly appears to be ‘sequential.’ This is not merely an observational error, but appears to be a rational model of observable reality. However … might it be otherwise? Does Block Theory have any basis? Might we live in a multiverse? If time is like a gramophone record, what decides where the needle (the present) is?

Which then leads you to ideas of time travel, and the problems with the (Unproven / unprovable) causality models that our understanding of Time seems to imply.

So then - back to the problems of Choice, Free Will, as against a Newtonian determinist clockwork universe, or perhaps Chaos and Complexity Theories. How does randomness fit into this?

Which probably leads back to theories of consciousness and the Twin Slit / Schrodinger’s Cat, Observer / observation changes the outcome issues of Quantum Mechanics. What is Consciousness? What is an Observation? What is a Choice / Decision? What is ‘An Observer’? What is Time?

But then, that’s right back to where we began.

So - We are into metaphysics and spirituality in a big way. Is there a Creator God? Is He (she, it, they, whatever) omniscient? Does ‘god’ know the end from the beginning? And who are you, me, us and them?

At this point you can try some of the yogic practices to gain a change in your conscious awareness of time.

When you’ve done all this you probably know as much about Time as anyone on Earth - probably a lot more.

And you still don’t know what time IS!!!

But if you can take the next step from there you will gain Nobel Prizes, shake the foundations of science and religion, transcend, and perhaps we will worship you.

Alternatively, you may just find it easier to read what’s on this site, and its links, and wait for my book to get written.

And if anyone does learn what time really is, I promise we’ll tell you.

Hope these thoughts helped a little.