What is time? And how can it be best defined?

Some argue that time does not exist at all. Because the past is now gone, the future has yet to come, and Now is only a distinction.

What exactly is time? Anyone might claim that time is “what the clock measures,” but this is not always the case. We believe that clocks are exclusively found in humans. Regardless of that it only works as day and night, animals have a time notion too. If time is not unique to humans, then it must exist outside of clocks.

Is time absolute, or does it exist at all?

Time is tied to the situation we are in, as are the seconds that pass. Many intellectuals and scientists have claimed that there is no such thing as time. Is time unchangeable? Perhaps this is the most profound question regarding time. Is time independent of the universe and everything else, or is it just a term for the order of events?

“On those who enter the same rivers, ever different waters flow.”


Is time an entity?

Using a similar approach to mathematics, one may ask, “Is mathematics an absolute object at the center of the cosmos waiting to be explored?” Or are such notions only human inventions? One thing is certain: whether we can perceive it or not, time is an “entity” that we pass through.

What is now?

Time has three components: Now, Past, and Future. The past is gone, the now is here, and the future has yet to come. For the “present time” we say “is progressing,” it links the past and the future by moving nonstop across the cosmos and our existence.

Then, what is it now? Is it an eternally tiny slice of time or the smallest possible piece of it? Could time be made up of an unlimited number of nows that follow each other?


Aristotle had a different idea. The preceding now must have disappeared while the current now is taking place. Now cannot vanish as it occurs since each now is finite; nevertheless, the now that follows it cannot disappear either. Because nows follow each other and cannot coexist.

“Time is the measurable unit of movement concerning a before and an after.”


Each part of the time is a thing of the past, while the next part will arrive in the future. However, none of the parts can be Now. Because Now cannot stand alone as a component. It just divides the past from the future. Others argue that time does not exist at all. Because, the past is now gone, the future has yet to come, and time is only a distinction.

Then, what is the present time?

Some argue that Augustine of Hippo provided the finest solution to the issue of what is time. He defined time in the definitive lines of Now; If segments of time that can no longer be divided into smaller moments are envisioned, this is what we mean Now; nonetheless, this entity flies so quickly from past to future that it cannot be expanded by any delay. Because it may be separated into past and future if expanded, yet the present time takes up no space.

By Jim Collins has Jim Collins on staff as a space writer. Jim is passionate about all things astronomical and space-related and always relishes the chance to explore more.