What is time?

Time is a construct developed by humans over our existence to separate events into years, months, days, minutes, seconds, and beyond. We have developed specific mechanisms and theories to calculate and observe time, but what really is it?

From a general perspective, time is the distance between events. Not distance measured in feet or meters, but the distance between one event and another. It constructs a timeline of past, present, and future events. Such events constitute the concept of causality. Causality is the idea of cause and effect. Through our understanding of time and causality, we can identify the separation and continuity of events throughout space.

But perhaps time is more complicated than simply a measurement.

Some may say that time doesn’t truly exist. In that construct, time becomes a relative term based upon the observer observing it. As we travel faster through space, time passes differently for us relative to another observer. At the speed of light, the nature of time becomes fundamentally different, as light follows a path with zero spacetime interval.

So how do we measure time?

We measure it through physical processes. Every clock, regardless of its design, is ultimately observing change. A mechanical clock measures the movement of its hands. An atomic clock measures transitions between quantum states. In this sense, perhaps we aren’t actually measuring time itself. Perhaps we are measuring change and using that change to define time.

This brings us to an even deeper possibility.

What if time is connected to information?

We can imagine the universe as a sequence of physical states. State 1 contains a particular configuration of information. Through physical interactions, that state changes into State 2. State 2 then influences State 3, and so on.

State 1 → State 2 → State 3 → State 4 → …

Each state contains relationships to the states that came before it and the states that follow it. Those relationships establish causality. If this is true, then perhaps what we call time is not an independent substance flowing through the universe. Perhaps time is the relationship between different states of existence.

The universe may have evolved from an initial state into the state we observe today, and it will continue into future states. If so, time could be understood as the ordering of those states—the relationship between what was, what is, and what will be.

This raises an enormous question.

If space and time are interwoven into what we call spacetime, where did each come from?

Are space and time fundamental properties of nature, existing at the deepest level of reality? Or did they emerge from some deeper layer of existence that we do not yet understand?

How did space emerge from time?

How did time emerge from space?

Or perhaps neither emerged from the other.

Perhaps both space and time emerged from something deeper—the relationships and correlations between the fundamental information that constitutes reality.

Could time emerge from relationships between entangled information that establish a causal structure?

If so, time may not be something that exists independently and carries the universe forward.

Perhaps time is the universe’s way of expressing the relationship between its states of existence.

And if that is true, then understanding time may require us to look beyond time itself—to the deeper structure from which reality emerges.