A Local Presentist Ontology of Time - a Scientific paper and blog post (bonus)

Scientific paper

Abstract: This paper proposes a fundamental ontology of time rooted in the concept of a localized "now," defined as the unique "latest event" at each spatial point (or minimal Planck-scale volume) throughout the universe. This "universal present" is understood as a logical collection of these independent local "nows," existing prior to and underlying the observer-dependent constructs of relativistic simultaneity. This framework asserts that at every location in the universe, there is a unique "latest event" constituting the "now" at that location, aligning with presentism. We argue that comparing presentism to the block or growing block universe as mere alternatives on the same ontological plane is a category error, as the latter are interpretations arising from a specific physical theory and its implications for spacetime structure, not fundamental ontologies of existence itself.

Keywords: Presentism, Time, Local Now, Universal Present, Relativity of Simultaneity, Ontology of Time, Philosophy of Physics, Block Universe, Growing Block Universe.

1. Introduction: The nature of time presents a profound challenge in both philosophy and physics. While Einstein's theory of relativity provides an invaluable framework for understanding the interconnectedness of space and time and the observer-dependence of simultaneity, it has also led to interpretations that challenge our intuitive grasp of the present moment. This paper argues for a fundamental, localized ontology of time based on the concept of a unique "latest event" at each spatial location, which forms a "universal present" as a logical collection of these independent local "nows." This view aligns naturally with presentism and offers a basis for understanding our experience of a singular, unfolding reality. The core assertion is that denying this framework necessitates a rejection of the principle that a unique latest event occurs at any given location throughout the universe. Furthermore, we contend that block universe and growing block universe models are based on the implicit assumption that Special Relativity's observer-dependent "now" represents the fundamental reality of time, leading to a confusion of secondary effects with primary ontology. Comparing these models to presentism as simply three alternatives overlooks the fact that presentism, as presented here, addresses a more fundamental level of existence than the spacetime structures proposed by the block and growing block universes.

2. The Local "Now": A Foundational Axiom Universally Applied: We posit as a fundamental axiom that at any given spatial point (or within a minimal quantum volume) anywhere in the universe, there exists a unique "latest event." This statement is considered self-evident, derived directly from the definition of "latest." The nature of existence at a point is sequential; one event precedes another, and this principle holds universally. To deny this is to deny the sequential nature of existence at a localized level everywhere. This "latest event" constitutes the fundamental "now" at that specific location, representing the basic ontological reality of that point in time.

3. The "Universal Present" as a Logical Collection Across All Locations: The "universal present" is defined as the logical collection of all such unique "latest events" occurring at every spatial point in the universe. It is crucial to emphasize that this collection does not imply a synchronized moment in a relativistic sense. The "now" at each point is independent and determined solely by the sequence of events at that location. This is analogous to a set of numbers; each number has an independent value, but they can still form a coherent set. The existence of the set is a logical consequence of the existence of its elements at every location, representing the totality of fundamental existence at what we intuitively understand as "now" across the cosmos.

4. Distinguishing the Local "Now" from Relativistic Simultaneity: The "now" defined in this proposal is distinct from the observer-dependent simultaneity described by Special Relativity. Relativistic simultaneity is concerned with coordinating events across distances based on the propagation of light and the relative motion of observers. Our "local now" is a more fundamental, ontological concept concerning the state of existence at a specific location, independent of observation from other frames of reference. We argue that block universe and growing block universe models mistakenly take this secondary, observer-dependent "now" as the fundamental reality of time, leading to the erroneous conclusion that past and future moments possess a similar ontological status to the present. This is akin to mistaking a map (relativity's description of spacetime) for the territory of fundamental existence.

5. Implications for the Ontology of Time: This localized presentism stands in contrast to the block universe and growing block universe models, which grant ontological status to past and future moments within a unified spacetime. We assert that these models are misguided because they implicitly assume that Special Relativity's framework reveals the fundamental ontology of time, rather than describing the observer-dependent relationships between fundamentally local presents. Comparing presentism, as a theory of fundamental existence, to these models, which are interpretations of a physical theory, is a confusion of ontological levels. If only the unique "latest event" exists at each location throughout the universe, then the past is gone, and the future has not yet come into being at every location. The "universal present" is the totality of what exists everywhere. Disagreement with this implication requires rejecting the fundamental axioms established in sections 2 and 3 and accepting a secondary, observer-dependent construct as primary.

6. Conclusion: A fundamental ontology of time based on the unique "latest event" at each spatial point across the universe offers a logically consistent and intuitively appealing framework that aligns with presentism. By distinguishing this local "now" as the fundamental reality from the observer-dependent "now" of relativity, we can establish a foundation for understanding our experience of a singular, unfolding reality without requiring the problematic existence of past and future moments at any location. This framework highlights the misguided nature of block and growing block universe models, which confuse the secondary effects of relativistic observation with the primary, observer-independent ontology of the present.

Blog Post

What is "Now"? A Simple Path to Understanding Time

(Hero Image Suggestion: A split image. One side shows a person looking at a clock with the caption "Our Intuition." The other side shows a complex diagram of spacetime with the caption "Physics' Complexity." A connecting arrow points from "Our Intuition" to a simplified representation of the universe as a collection of independent points each with a highlighted "now.")

What is "Now"? A Simple Path to Understanding Time

We all know what "now" means, right? It's what's happening right here, right now. But when we delve into physics, especially Einstein's theory of relativity, the concept of "now" gets… complicated. Suddenly, "now" becomes relative – what's "now" for you might be the past or future for someone moving at a different speed.

But what if we're overthinking it? What if the "now" we experience is actually the most fundamental reality? Let's take a simple, logical journey.

Question 1: Are things happening at the location where you are right now? (You will likely agree: Yes)

Question 2: Is there a specific event that is the most recent event to have happened at your exact location? Even if it's just the movement of air molecules or a neuron firing in your brain, isn't there always a latest thing? (You will likely agree: Yes)

Question 3: Can two different events be the absolute latest event at the exact same location at the exact same time? (You will likely agree: No. By definition, "latest" implies it's the most recent and therefore unique at that instant.)

Question 4: Now, let's imagine an alien living in a galaxy far, far away, say Andromeda. Is something happening to that alien now (in the simple English sense of the word) at their location, even if it takes millions of years for the light from that event to reach us? (You will likely agree: Yes. Their "now" is independent of our observation.)

So, if we agree that at every point in the universe, there's a unique "latest event" – a local "now" – then the "now" of the entire universe is simply the collection of all these independent local "nows." It's like saying all the individual trees in a forest exist "now," even if they are far apart.

This simple, logical view aligns with the idea that only the present moment is real – a philosophy called presentism. It suggests that the past is gone, and the future hasn't happened yet.

The block universe and growing block universe models, which suggest the past and future have a real existence, arise from a key assumption: that the observer-dependent "now" described by Special Relativity is the fundamental reality of time. They take a consequence of how we coordinate events across distances and elevate it to the primary ontology. This is a misguided approach, confusing a secondary effect of observation with the fundamental, observer-independent "now" that governs existence at each and every location.

Maybe it's time we went back to the simple, powerful "now" of our everyday experience as the foundation of reality. What do you think?