Our brains do not contain a timer or a clock, which is why five minutes of scrolling through TikTok feels shorter than five minutes of facing the wall. Physicists used to theorise that time was sequential until Albert Einstein, history’s greatest physicist, challenged that notion.
He once stated that when you put your hand on a hot burner for a minute, it feels like an hour. However, sitting with a lovely girl for an hour will feel like only a minute has passed. What Einstein meant was that time is relative towards the observer. Hence, the question of the day: Is time just a social construct, or does it actually exist?
It is time (no pun intended) to find out the answer!
How do we sense time?
How we experience time depends on several factors, such as our level of attention, emotions, and memories. As the saying goes, “Time flies when you are having fun”. Studies have even shown that time speeds up the higher you live. The concept and perception of time are not fixed to a single region in our brain. It involves various parts of the brain, such as the hippocampus, cerebellum, parietal cortex, basal ganglia, and frontal cortex.
Humans also sense time based on how our body feels. Depending on specific times of the day, we might feel energetic, sleepy, or hungry. This is due to our body’s circadian rhythm, also known as our body’s own 24-hour biological sleep-wake cycle, helping us maintain awareness of the specific time and control our body’s regular vital functions.
In fact, even without being able to understand the concept of time, animals such as goldfish, rats, birds, and dogs, can sense time; they know when feeding time is. Therefore, it is evident that our view of time is not limited to the calendars and clocks.
So, what exactly is time?
Time exists in everything, from the changes in our surroundings, such as seasonal change and the rising and setting of the sun, to our body functions, such as the biological ageing process. Time flows in a forward motion, from the past to the present and into the future. Stephen Hawking theorises the thermodynamic arrow of time and the psychological arrow of time that time is constantly moving in a single direction.
Do the past and future exist?
Our perception of time is relative to what we see in the immediate moment. For hundreds of years, time flowing from past to future has always been theorised to be constant throughout the universe. However, Einstein revealed his theory of general relativity in 1905, proving to us that time is neither linear nor absolute. His theory of general relativity states that time depends on the individual’s frame of reference and, therefore, cannot be absolute. The faster you move, the longer your time will be. Hence, the theory of time dilation.
The actual fabric of reality
Einstein theorised that time and space are stitched together to form a single spacetime fabric, embedding together everything this universe holds. This fabric is continuous, smooth, and bends around energy or matter. Therefore, the sun, which generates a huge amount of energy, is able to bend the spacetime fabric, resulting in the surrounding planets revolving around it, creating gravity.
Time seems to flow differently when shifting from a biological level to a cosmic level. In the spacetime continuum, there is no clear distinction between the time periods. My now differs distinctively from yours now because Einstein’s theory of general relativity states that there is no absolute now.
Conflicts in modern physics
Since the start of quantum mechanics, the world of physics has achieved significant breakthroughs, understanding how the world functions at the level of tiny particles, such as electrons. One of the most significant breakthroughs made in modern physics was the combination of quantum mechanics with Einstein’s theory of general relativity, creating a more general theory, such as quantum gravity.
However, it also created a conflict. Time is absolute in most quantum mechanics theories, while time is dynamic in the theory of general relativity. Hence, the two physics theories imply that while time does exist, their theories are bound to clash with one another fundamentally.
By the end of the 20th century, physicists came up with new theories to approach quantum gravity and its two clashing fundamental theories. Among them was loop quantum gravity, which ended up being the most stable and reliable solution. Yet, it is not perfect, as time does not exist in the loop of quantum gravity. So it seems like the world has yet to grasp how our universe functions fully.
Why did humans create the concept of time?
Time has been and will be, for a long time, a mystery. While time does exist, at least from our understanding, it is a social construct that humans have created to navigate and better manage our lives. We create such a social construct to help us measure our events’ duration, from seconds to years. Without time, while modern physics may work out fine, our modern life may be messy.
Putting aside the latest physics findings, the fact that science still has to rely on time and its related mathematical formulas proves that time is more than a social construct. The second law of thermodynamics would not exist without the existence of time. Additionally, the social construct of time has long existed, even before mankind came up with physics theories. Even if time is proven to be non-existential, it is still vital for us.
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