Time is an unconscious day-to-day “thing” that humans experience, yet it is also a convoluted concept that is extremely arduous to fully understand or to perceive. What is time? How does time work? Are humans capable of understanding time with their physical limitations? Time is a quality of existence and a dimension of space that defines the duration between events. Furthermore, time quantifies the rate of change of physical and conceptual objects. This is essential for the existence of the universe and is therefore crucial for the existence of humanity. Without time, no event could begin, progress or end. Time is a dimension of space; the concept of time must be proportional to the scope of the object that experiences time. Time is a concept that spans from the quantum scale of subatomic particles to the galactic scale of the entire universe. Humans are not capable of understanding comprehensive theories of time with their limited intuitions and senses without the use of mathematics and physics. This is because the scale of time at which nature operates is far beyond the reach of typical human contemplation. Many time paradoxes that are difficult to solve makes time a difficult concept to fully understand. For example, the causal loop paradoxes are very difficult to comprehend. With the help of mathematics and physics humans can gain a partial understanding of temporal mechanics. However, theories of time became extremely contradictory and mutually conflict and obscure each other.
Humans are not capable of understanding time solely based on their intuitions and their senses without the utilization of mathematics and physics. This is authentic because humans are too microscopic in comparison to the currently posited scale of nature. Human senses are too narrow; all fives senses: sight, smell, taste, touch, and sound can only perceive a minuscule part of nature. To start off, the complete electromagnetic spectrum ranges from one pico-meter (10^−12 meters) to one mega-meter (10⁶ meters). Yet, human eyes are only sufficient enough to perceive 400 nano-meters to 700 nano-meters which is only about 0.0035% of the entire electromagnetic spectrum. The electromagnetic spectrum is the fundamental building block of the universe as we know it because it is one of the four fundamental forces. In addition, human auditory perception is quite limited too. Sound frequencies that are perceivable by living things on earth range from 10Hz to 200,000Hz. For example, bottle-nosed dolphins can hear from 70Hz to 150,000Hz. In comparison, humans can only hear sounds at frequencies from about 20Hz to 20,000Hz — that is only 0.01% of all sounds that are available! Like human sight, people’s auditory capabilities are equally limited. With these sensory limits, it is logical to conclude that human understanding of time is not necessarily accurate. If humans are unable to perceive the complexities of nature, then it is rational to conclude that the human sensory intuition may not possess adequate capabilities to fully to understand the complexities of time. However, with the help of mathematics and physics, humans are able obtain and develop an intellectual understanding of the universe. The current understanding of time through mathematics and physics is logical but far from being instinctive to an average human. Scientific disciplines such as quantum mechanics and general relativity can augment our temporal sensibilities. Certain aspects of time derived from these disciplines have been proven to be true but they are still difficult to understand by the average human. Due to the unreliability of human intuition, adherence to mathematics may yield better results in the search for improved understandings of time. Nevertheless, these theories are the counter-intuitive for many humans. Therefore, due to the limitations human senses and their unreliable intuitions, humans are still yet to be capable of understanding time completely.
There are many paradoxes that are interwoven with time. Three of the most famous time paradoxes are the causal loop paradox, the grandfather paradox, and the Omphalos hypothesis (or Last Thursdayism). The causal loop is quite literally a loop that is created by causes. This means that a future event is the cause of a past event and the cause of that future event is the past event. Did the future cause the past to happen or did the past cause the future to happen? The fact that the origin of this loop is untraceable made this loop a paradox. For example, Bob gets a watch from an old lady named Alice. Later, Bob travels back in time when Alice was still a little girl and gives her the watch and tells her to give this watch to Bob in the future. In this case, the origin of this loop is indeterminable. This is paradoxical because the objects and information that are involved in this loop are “self-existing” and “resetting.” What this means is that the information in this loop is independent from any past. “It just exists.” It is resetting because people in this loop will not be able to remember or to notice that they are in a loop. Therefore, this makes it impossible for them to escape the loop. This raises an interesting philosophical dilemma; If everything that will happen has already happened, can anything really be changed? Does free will exist? No one can determine if they are making their decision or they are just acting as if they have made the decision that they have already made during the loop. Nobody can be certain of how many times a causal loop has happened. The dilemma exposes the paradox about whether one knows that he/she is lacking freedom of choice but still acts like he/she does. Secondly, the second time paradox is called the grandfather paradox. If a person traveled to the past and killed his/her grandfather. Does this means that this person’s father/mother will not exist and consequently this person will not exist? Then who killed the grandfather if this person never existed? In fact, this paradox applies to any inconsistency in past events. For example, a famous variation of this paradox is the “Hitler paradox”, where a person allegedly went back to the past and killed Hitler. The problem arises; If Hitler never existed due to this action, then there are no reasons for the occurrence of time event. Last but certainly not least, Omphalos hypothesis or Last Thursdayism raises the question: Did the past really happen? What if everything that existed was created last Thursday? What if people’s memory are just pre-programmed to be there? In fact, it is impossible to prove it incorrect because Last Thursdayism is falsifiable. This means that any argument that goes against it can be classified as the “everything” that was created last Thursday. Thus, this makes it impossible to disprove. This idea does not need to be applied only to last Thursday, it is a general concept that can be applied to any period of time in history. It shows that humans are not capable of proving when reality started. The concept of time is difficult for humans to fully understand as it is bundled with many paradoxes that humans are incapable of solving.
What prevents humans from understanding time completely is not only their physical limitations, but more significantly, how time works in physical reality. It was not until the 1920s, fifteen years after Einstein published his study on Special Relativity, did the physics community understand and accept the concept of relativity. Einstein stated that: “If a system of coordinates K is chosen so that, in relation to it, physical laws hold good in their simplest form, the same laws hold good in relation to any other system of coordinates K’ moving in uniform translation relatively to K.” In other words, physics works the same for the observer of an event of K, if the observer is moving uniformly with K. For instance, if Bob bounces a ball on a train while Alice (who sits besides Bob) observes this event, Alice and Bob will both perceive the same up and down motion of the ball. On the other hand, if Alice were to observe this event on the ground as the train passes by, the motion of the ball will no longer be strictly up or down, but bounces with a slanted motion. This is because the velocity of any objects that were on that train contains the train’s velocity. Thus, when Alice is on the train she can only observe the ball’s vertical velocity because herself and the ball have the same train velocity. Through this simple idea, many of Einstein’s theories were formed. One of them is Relativistic time. The faster an object moves; the slower the time goes for this object. Recall the bouncing ball example explained above. Now imagine that every bounce of the ball takes one second. Alice on the train will see that the ball takes exactly one second to complete a bounce, but Alice on the ground will see that the ball takes a little longer than one second to complete a bounce, since it takes the ball longer to bounce back on a slanted path than a vertical path. With this idea in mind, it is easy to theorize that the faster the train move, the longer the slanted path for the ball. Therefore, the ball takes longer to bounce back for the ground observers. Time would get slower and slower for objects on that train as that train approaches (but never reaches) the speed of light. It will never reach the speed of light because time stops for anything at the speed of light. This means that anything at the speed of light experiences no time, everything happens instantaneously. Since objects at the speed of light experiences no time, it is logical to say that anything that experienced time before (all the objects on that train) must not be at the speed of light. This concept of relativistic time was proven to be true by the time differences between two atomic clocks. One clock stayed on the ground while the other clock was carried on an airplane. An atomic clock is a clock that measures a second by the number of “jumps” an electron makes between energy levels (like the bouncing ball example above). It took the physics community fifteen years to understand and accept this concept of time. This is because physics scholars, believed in Newtonian time (where time is considered to be constant regardless of velocity). With the complexities of time, it is difficult for humans to understand time intuitively since it is extremely unlikely for human to ever approach the speed of light when relativistic time starts to matter.
The problem of time is a famous problem that was caused by the contradictoriness of quantum mechanics and relativity. These two theories while being very useful and partially proven to be true, their explanation of reality is genuinely incompatible. There are many incongruous ideas and concepts between the two. To begin, their definition and utilization of time is inconsistent. In quantum mechanics, time is universal and absolute. Which means that time is independent from velocity. Time in quantum mechanics is understood to have steady ticks dictate the evolving entanglements between particles. On the other hand, time explained in relativity is to be relative and dynamical based on velocity. It is a dimension that is coherently intertwined with directions x, y and z into a four-dimensional “space-time” fabric. Objects at different velocity experiences time differently explained in the previous paragraph. Another fundamental contradictory is their description of past, present, and future events. These two systems can be though as “smooth” and “chunky”. In general relativity, all events are continuous without any discontinuity with a deterministic nature. In quantum mechanics, events produced by the interactions between subatomic particles have jump discontinuity (or namely quantum leap) with probabilistic rather than definite results. An example would be quantum entanglement. Where a group of related atoms acts correspondingly to each other despite the distance. It will be dreadfully wrong if one were to interpret this “chunky” quantum entanglement with “smooth” relativistic laws. Finally, these two theories also breaks down on each other’s magnitude. For instance, relativity will give nonsensical results when it is used to model quantum sized entities. It will eventually descend to infinite values in its description of gravity. On the other hand, quantum mechanics will be in serious trouble if it is used in cosmic dimensional calculations. Since per its quantum field theory, any space even if empty contains a certain amount of energy. With this theory, any space with a large amount of energy it will create a black hole so strong that will cause the universe to fold in on itself. This demonstrates that relativity and quantum mechanics mutually conflicts each other.
In conclusion, time is a challenging concept for people to understand because of human’s physical limitations, unsolved paradoxes, strange behavior of relativistic time, and the incompatibility between theories. Humans are physically insufficient to fully perceive how time works, because it is not able to completely capture all the information that nature have provided. Time paradoxes are very difficult to thoroughly comprehend, since human can only experience time in the forward direction. Time of any object is relative or dependent of this object’s velocity, the higher the magnitude of the velocity the slower the time this object relative to other observers’ experiences. Although relativity is used to explain time and proven to be true, it is in a significant contradictory relation with quantum mechanics. In the final analysis, time is simple yet complex, should people keep on pursuing for the ultimate explanation of time even if it is difficult, because it allows people to keep on advancing in physics and ultimately understand the universe and this reality.
Hope you liked this article, I wrote this in 2016 but never published it. Like always, thanks for reading, and have a great day!