Is Time a Construct Defined by Universal Calculations?

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My colleagues often joke about the nature of time. It raises the question: is time even real? Just the other day, I thought a deadline was tomorrow, but was it actually today? This idea sparks the thought that maybe the 1980s truly weren’t 40 years ago after all. If extraterrestrial beings observed Earth from afar, would they witness dinosaurs or merely a sea of molten rock? Clearly, time can’t be as fixed as we perceive it.

Yet, like many jokes, there’s a kernel of truth in this one. It’s not that time isn’t real; it’s more about our lack of understanding it. And by “we,” I mean humanity as a whole. Physicists and philosophers have grappled with this concept for centuries, presenting various theories—some plausible, others less so—but without definitive answers.

I posed the question to Stephen Wolfram, a prominent physicist and computer scientist renowned for developing sophisticated computational tools. For decades, he has spearheaded the “Wolfram Physics Project,” a significant effort aimed at redefining physics through computation rather than conventional mathematics and thermodynamics. While his proposals have sparked intrigue, they have also stirred controversy within the scientific community. Notably, Wolfram’s musings suggest that the universe operates as one colossal computer. If validated, this could revolutionize our understanding of time, such as why it appears to flow uniformly and why the future remains elusive. I reached out to him for insights.

Leah Crane: Let’s start with a fundamental question. What is time?

Stephen Wolfram: Time is an essential act of computation.

Leah Crane: Great! That concludes the interview—have a fantastic day!

Leah Crane: That’s intriguing, but can you elaborate on what that means?

Wolfram continues, “Time reflects the experience of a continuous computational process that calculates the universe’s state.”

Leah Crane: Is it similar to stacking images in a flipbook to create motion?

Absolutely, though it’s a bit more intricate. These successive states unfold one after the other based on established rules over time. However, this raises a perplexing question: if there are clear rules dictating the universe’s state, why can’t we effortlessly predict the future? This relates to a concept I’ve termed “computational irreducibility.”

Leah Crane: What does irreducibility imply, and why does it hinder time travel or future predictions?

Understanding a system’s foundational rules doesn’t automatically lead to knowing its future state. Typically, we expect to derive outcomes using formulas, determining future states with ease. Instead, with certain systems, running the rules often reveals that the only path to understanding outcomes is through step-by-step calculations. Irreducible computation necessitates traversing the entire evolution of the system, leaving no room for shortcuts.

Leah Crane: Could you share an example of something computationally irreducible, outside of the universe as a whole?

Consider calculating the digits of pi. While there’s a defined method for finding these numbers, you cannot simply calculate the 1200th digit without determining all the preceding digits first.

Leah Crane: So it’s akin to climbing stairs in the dark, where you don’t know where the next step is until you take it?

Precisely. The challenge comes from encountering unpredictable steps. In our reality, predictability is vital; without it, navigating challenges becomes extraordinarily difficult.

Leah Crane: Thus, irreducible computation resembles climbing an unpredictable staircase in the dark, making time travel implausible, and future states non-predictable due to human limitations?

Exactly. As observers, humans have finite computational capabilities. For instance, with encrypted messages, we cannot unearth the original content just by glance. We often require exploration of all alternatives to decipher meaning. Consequently, computational irreducibility implies that humans are bound by limitations, unable to perform full, complex calculations, preventing us from predicting distant states.

Leah Crane: If my cognitive abilities improved and I climbed stairs effortlessly, would I be able to foresee the future?

If your computational prowess exceeded that of the universe, then potentially, yes. However, given that all our computers stem from the universe’s materials, predicting the universe using them poses challenges. We cannot forecast the universe from within its confines.

Leah Crane: If calculations govern everything, does this imply a hyperdeterministic reality? Where does human agency and free will fit?

In a deterministic framework, one might conclude, “Knowing the rules allows me to predict every outcome.” But with irreducible computation, the only way to determine outcomes is through direct computation—meaning you can’t rush the system. You must engage with it closely to discern future developments.

On one hand, that may limit science’s predictive capabilities. But on the other, our experience with time allows us to accomplish significant things shaped by these irreducible calculations.

Leah Crane: This gives our existence meaning beyond standard superdeterminism. Regardless of free will’s existence, we can’t predict our next move.

The existence of fundamental rules doesn’t entirely negate the significance of choice within those boundaries. Although we’re subject to these laws, they don’t provide a complete blueprint for our actions. Even straightforward rules can generate complex behavior. Free will might exist independently of these core laws—or alternatively, exist as random events without designated influences from previous states. If this arbitrary concept governed the universe, scientific laws would ultimately fail since randomness would prevail. However, even under a seemingly chaotic universe, grasping a comprehensive view would still be improbable.

Leah Crane: Thus, we must accept that physical laws are limited. You couldn’t assert, “I will transform into an orb,” without reducing the meaning of free will.

Indeed, once definitive laws govern the universe, traditional notions of free will can no longer apply. Why are we led to believe we possess free will? The mystery lies partly with computational irreducibility. If one could always predict future actions, the illusion of choice dissipates. We may find ourselves merely as observers while the universe directs our next steps.