Time

It is something we never have enough of. People go through their lives enslaved by its captivity and utter control. We always we wish had more of it, but it never seems to be enough. I am talking about one of the main constants and boundary on our lives, which is time. It is also a means of measure, if subconsciously, of the span of our presence in this existence. It seems to tick away equally for all of us, no matter who we are or how much or little wealth we have. The passage of time is intertwined into human perception, and we feel it ticking away in a manner that is more intimate than say with space or gravity. It is one of the few things we humans all agree on with no real disagreement. We have divided the world equally into many time zones to adjust for a location's position relative to the sun. Time literally is the measure by which we live our lives and what we do while our body's clocks tick towards the end. It is compared to a rolling stream or a flying arrow, ever carrying us from the past to the future. And the entirety of our digital lives require time, specifically a clock signal, to function. Without it, none of the basic elements of modern life or the wonders of gadgets that have taken over our lives would function. Every electronic circuit or system always starts with a humble chip that sends out a time signal upon which utterly complex systems are built. But while we have all agreed on how to measure time or even generate it via chips, not much thought or consideration is given to what time is or where it came from. Philosophers and scientists have debated for eons on whether time is a fundamental aspect of reality or just a human construct. The theory of general relativity says that time is intertwined with the fabric of space and affected by gravity. Those of religion claim it originated in divinity but can offer no explanation of the 'how'. Let’s see if we can somewhat de-mystify some of what time is all about.

Our perception and understanding of time are divided into three basic parts: the past, present, and the future. Our means of communication by language is built around these divisions. We think of the past in terms of things that have already happened whereas the future is somewhat undefined, with us only making determinations based on memory. For example, we know the sun will rise in the morning and set in the evening based on us seeing it and that being stored in our minds. The 'now' or present is the most interesting of these because it is where events that were in the future are manifested into the reality of the present. But it is fleeting as the 'now' is ever elusive and becomes the past before you can even realize it is the 'now'. In most ways, it is only the present that really matters as the past only exists in our memories and the future in our imagination. But what seems obvious to the average person is completely at odds with physics. Einstein's theory of relativity does not assign any significance or value to the present. He once wrote to a friend "The past, present, and future are only illusions, even if stubborn ones." This is because, according to the theory, there is no simultaneity to events and only depends on the frame of reference. For example, the sun is putting out massive amounts of light which reaches the earth in approximately 8 minutes. So, what is 'now' on the surface of the sun is only 'now' here 8 minutes later. For an astronaut in a spaceship near Venus, 'now' is about 6 minutes. Finally, the 19th century physicist Ludwig Boltzmann wrote: “For the universe, the two directions of time are indistinguishable, just as in space there is no up and down.” So, time, especially as we understand it (past, present, future) does not seem to exist in science.

The Scientific View

Time is also far more "physical" than most people realize. According to Einstein's general theory of relativity, space and time are woven together in what is known as space-time. And as has been observed and validated many times, space-time is affected by that other mysterious force in the universe…. Gravity. Near objects that have strong gravitational fields (like planets), space-time bends and curves. Imagine space-time as a vast sheet of cloth. When a heavy object is put on this fabric, it creates a dip or a curve. Planets orbit stars not because they are being pulled by the star but because they are following the curved space-time caused by these massive objects. Thus, the passage of time is relatively different in regions that experience different gravitational fields. When a planet is closer to a strong gravitational field of a massive star or another planet, time passes slower compared to an object that experiences a weaker gravitational pull. The more gravity somebody experiences, the slower time passes for them relative to someone in a lower gravitational field. On earth, the effect is minuscule but measurable. For a person in Denver, Colorado in the US, time ticks by a little bit faster given it is a mile above sea level. This is because the gravitational field is slightly bit weaker than at sea level. This is also why objects that are in orbit, where gravity is weaker, must sync and adjust their clocks by synching with each other and with clocks back on earth. So just within our planet, time is not the same for everybody and general relativity matters for systems that require a synchronized clock signal.

Everything we think we know about time really breaks down when observing space-time behavior near a black hole. This is an object (nobody really knows what else to call it) that has a gravitational field so strong that nothing, not even light, can escape it. It is defined by what is known as its event horizon, the boundary where the escape velocity needed is greater than the speed of light. It is typically formed by the death of a massive star, where the core gravitationally collapses onto itself. It is here that space-time is so curved that time slows dramatically creating an effect called time dilation. It is theorized that upon crossing the black hole's event horizon, time ceases to exist altogether. The 2014 movie Interstellar illustrated this concept of time dilation near a black hole. In the movie Laura Miller, one of the characters, lands on a planet that is next to a massive black hole and thus within the curved space-time caused by the black hole's gravity. The time dilation is so massive that a single hour on Miller's planet is equivalent to 7 years on Earth!! A similar effect is observed when flying close to the speed of light. While the pilot would experience time locally as if normal, relative to earth time he would age far less than those on earth. Finally, we can see into the distant past and even into one that may no longer exist. If we observe a star that is 10 light years away from us (a light year is the distance light can travel in a year), what we see in our present is really what was 10 years ago for the star. If it collapses, we will not know about it for 10 years after the fact. So, in this context, time is very relative to us.

Light is also another thing that does not seem to be affected by time. In fact, it has been theorized that light does not experience space or time. We know a photon of light travels at around 300 million meters/second and a light year is how far it travels in a year. But at this speed, theories of relativity state that no time passes for the photon, similar to what happens near a black hole's event horizon. And if this is true, then the photon is in every place at every time, all at once. This is backed up by quantum mechanics where quantum superposition proves that a photon exists in every state all at once until it is observed. Taking this theory further, for a photon that originated in the big bang, no time has passed for it. But for us on earth, we can say (relative to us) those photons are about 13.8 billion years old. It gets even weirder because the theory of relativity states that space contracts infinitely at the speed of light. Which means, for the photon, there is no space, and the entire universe would be smaller than an atom. So, no time passes for the photon, but it passes for everything around it (relativity).

The Relevance of Time

Physics needs the concept of time to describe changes as a sequence of events. Thus, there exists the concept of 'absolute time' which we assume is constant throughout the universe. This is the only way we can not only stay in sync with each other but also with everything going on in the universe and beyond. This also brings to fore another requirement for time to exist, which is space. Because most physics and the sciences involve measurements of objects or events that occupy space, the two are taken together. This is where the concept of space-time comes about as the two are interwoven, at least for what humans need to stay synchronized and measure aspects of our reality. And in that sense, time is independent of our perception but exists as defined by science. This "arrow of time" as it’s known (past > present > future), is really only understood in a thermodynamic sense in that the entropy (measure of disorder) of systems increases in the direction of that arrow. Our bodies are the best example of this as we start with low entropy and die with high entropy. But the question arises of why we cannot move around in the dimensions of time (past, future, etc.) the same way we are able to move in 3-dimensional space? The current theory is that we have not fully understood time as a dimension that can also be traversed in the same manner as space.

Another area of science where time does not seem to have any relevance is quantum mechanics. As I explored in that blog, there are many instances of quantum phenomena that defy everything we define as time. The first example is the system of superposition where a particle exists in all possible states all at once. So past, present, and future are all present for the state of that particle at any time as we perceive time. But, when we go and measure that particle, it settles into a single state in no time, at least as we are able (or not, in this case) to measure. The second example is the delayed-choice, quantum eraser experiment where information on which slit a photon passes through is "erased" by scrambling the information on the entangled pairs. This then results in the original particles changing back to a wave-interference pattern even though we knew which slit they went through, which should result in a particle pattern. Even entangled particles seem to defy time by the change of pair behavior being instantaneous even when separated by a vast amount of space. A Chinese experiment to measure state change of entangled photons found that it was at least 10,000 times faster than the speed of light.

The laws of physics that govern the motion of objects in the quantum world do not distinguish the direction or flow of time. To be specific, this means that the basic equations of motion for classical and quantum mechanics are reversible. Changing the direction of the time coordinates of an equation still constitutes a valid evolution process. This concept is known as time reversal symmetry and is found throughout quantum theorems and equations. This all then goes back to the concept that time is an emergent function of a particular process and not an objective reality of constant. In that sense, time for us only has meaning after we are born (it is emergent at birth) and ceases to have meaning after we die. If our bodies never aged or our minds never diminished in capacity, time would not have the same impact or perception for us.

The Block Universe Theory

This model of our reality states that our universe can be looked upon as a giant four-dimensional block of space-time containing all the things that ever happen at any place and at any time. There is no 'now' or present because all moments just exist relative to each other within the three spatial dimensions and one temporal dimension. Your perception of the present is simply just a reflection of where in the block universe you are at that instant. Within this structure, we insert ourselves (born) in a certain location, exist for one pathway among infinite ones, and then remove ourselves (die) from that construct. Somebody looking in from the outside would simply see a block with near infinite "moments". But for those inside, you only see and experience where you are currently. Dr. Kristie Miller, the joint director for the Center for Time at the University of Sydney has described this concept in detail and is illustrated by the following diagram.

Figure 1: Illustration of the Block-Universe Theory

(Image Source: Interesting Engineering)

Think about the idea of 'here now'. I can say that I am here now writing this. But when you read it, you can say 'I am here now' and also be correct though your 'here now' is different to mine. From that view, past and future exist just based on your location inside the block-time continuum; past is any time and events at those times that are earlier than my location and future is later than my location. But for somebody in say your future time, it is their present. Just like the perception of left and right is a relative (to you) concept, so too are past and future. Depending on where you are observing from, all of those can be reversed. Block universe is an interesting concept. Here are links to some videos that try to make some sense of it (Link, Link, Link).

Since all time and spaces exist all at once in the Block Universe, time travel becomes a possibility. But being able to make it a reality will require some means of transport that can travel at or near the speed of light. This would result in time dilation which would slow time for the passengers enough to arrive in the future. Going back in the past would be more difficult, requiring something like the theoretical wormhole that rips a shortcut through space-time. But we would not be able to change the past as everything all time exists already. You can change your location in space-time to go to the past, but not the events that are already there.

Time really changes in our perception too. When having a bad day, time seems to slow down. When you are a kid, at least for those of us who grew up in the analog world, time went by way too slowly and we were often bored. When you are doing something exciting, feeling very happy, or having fun, time seems to fly. Think about an evening with a good friend where 5-6 hours seems like minutes. Time also seems to go faster as we get older. When we were kids, days were long, and we had the privilege of experiencing that elusive experience called boredom. As we age, days seem to fly by and nobody has time for anything other than run ever faster. But time has not changed as measured by a clock, only the curated perception of time and reality as presented by the mind. And even our perception of 'now' does not really exist by the time the mind catches up to you observing and recognizing it. "Now" is just a dimensionless point on the arrow of time; it is part of the perception of time but does not include the concept of duration. Because of this, the mind has to curate your reality in this moment in time, but that is one that has already passed.

The Yogic Perspective

The Yogic sciences and eastern religions and philosophies look at time in a very different manner. Yoga starts with the fact that the body is only an accumulation of the earth (via food) and the mind is made up of the accumulation of memories starting with when we are born. The goal of Yoga is to help put some distance away from you and what you have accumulated, the body and mind. This is accomplished by entering deeper levels of meditation where time starts to have a looser effect on you and the body. In this sense time is an emergent dimension as is space, both being consequences of being in a body that starts its journey towards death from birth. It is the measure of this journey that is called time and the dimensions needed to host the body is called space. If you did not have a body, there would be no need for time or space. Even in shallower levels of meditation, it is possible to suspend time for yourself, though the body carries on being affected by it. At very deep levels of meditation, it is possible for you and the body to transcend time altogether. There are many stories of yogis who sat in meditation for days and even years with no need for food and showing no signs of ageing. What enables this is the fact that the body is only created as a temporary space within which you conduct your Karmic experiments. If you can separate your consciousness (the real YOU) from the body, then time has no hold upon you. This goes back to the basis of Yoga and many eastern spiritual practices which state that it is our consciousness that creates time and space upon a vast quantum field of zero-point energy. And that the quantum particles create and destroy reality on-demand further adding to the perception of time.

The concept of block time also seems to support the requirements of the Yogic principle of Karma. In our real state of pure energy, there is no way to experience all the things that gross reality offers and hence we need a space to do so. This reality is created with every time already there in a block structure, and the only thing that changes is our perception of parts of this block. So, in order to create the different perspectives, we experience, there has to be this illusion called time. Again, time is an emergent phenomenon based on our consciousness assuming physical form in this block-time structure. As our consciousness shifts through the near infinite parallel realities every second, the perceptions of change, space, and time emerge. This is why during meditation, especially as you reach deeper states, the effects of time start to diminish because you are unentangling yourself from the physical experience, if only for a short while. There is also another component that diminishes during meditation (and sleep) and that is memory. Our mental recordings that began at birth give us the perception of a past and allows us to leverage them to imagine the future.

Reflections

I will have to say this is one of the few blogs where it really took me a lot of time (no pun :-)) to try to understand all the concepts I was learning about. That is because nobody has really solved much about the origin of time or is able to explain it in the context of relativity. Many scientists have proposed interesting theories and provided evidence that time is not the constant we think it is but none conclusively so. But all do agree that time is intertwined with space and thus the accepted and proven concept of space-time. Yoga and spirituality do state that time (and space) is an emergent dimension and only relevant because we have a body. Because we are neither our body nor our mind, it is possible via practice to distance ourselves from both. Doing so lessens the effects and perception of time, and it is possible to transcend it altogether. If our bodies did not decay and we were able to completely turn off the mind, then time really does not exist.

For all practical purposes and the normal experience of life, just accepting time is a constant is the best way. At the physical level, time is a necessity, and we cannot really function in the world without accepting that. But I also do believe that we can experience states of consciousness that are free of the effects of time. One way we experience this is every night when we go to sleep and have dreams. Dreams have their own localized timelines, and most times carry no synchronization with the time the body is keeping. We are not aware of the passage of body-time until it decides to wake you up because the sun came up or you must go pee. Meditation, of course, is the only controlled way that I have been able to find where there is no timeline at all, unlike in dreams. In some of the states of meditation I have been able to experience, I really have reached a sort of timeless state which also comes with the experience of nothing and no memory. It is hard to determine how long this state lasts but so far, the longest I have experienced is a few minutes. In my experience, meditation is the fastest way to get to that state, though it takes time and practice.