The Why of Motion: A Temporal Framework

J. Rogers, SE Ohio, 15 Mar 2025, 1902

Abstract

The continuation of motion after a force stops being applied is a fundamental phenomenon in physics, traditionally described by Newton’s first law of motion (the law of inertia). However, this law does not explain why objects in motion stay in motion—it merely describes the behavior. This paper presents a novel explanation of motion within the "time-experience" framework, where inertia is reinterpreted as the resistance to changes in a particle’s proper time experience along its worldline. This framework provides a deeper understanding of motion, contrasting with the descriptive nature of standard frameworks.

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1. Motion in Standard Frameworks

To appreciate the explanatory power of the Time-Experience Framework, it is essential to first understand how motion is treated within the established paradigms of classical mechanics and Einstein's theory of relativity. While these frameworks provide remarkably accurate and powerful tools for describing motion, they leave fundamental questions about the underlying nature of motion and inertia unanswered.

1.1. Classical Mechanics: Motion Governed by Forces and Inertia

Classical mechanics, built upon the foundational work of Isaac Newton, provides a robust and intuitive framework for understanding motion in our everyday world. Its cornerstone principles are Newton's Laws of Motion:

• Newton's First Law (Law of Inertia): The Principle of Unexplained Continuation

  • Statement: "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force."

  • Significance: This law introduces the concept of inertia – the inherent tendency of objects to resist changes in their state of motion. It establishes that uniform motion (constant velocity) is as "natural" a state as rest. It rejects the Aristotelian view that constant force is needed to maintain constant motion.

  • Description, Not Explanation: While profoundly insightful, Newton's First Law is fundamentally descriptive. It accurately describes what happens – motion continues unchanged in the absence of forces – but it offers no explanation for why this is the case. Why do objects possess inertia? Why does motion persist? The law simply postulates inertia as an intrinsic property of matter, leaving its origin and mechanism unexplained.
    
    

• Newton's Second Law: Quantifying the Change in Motion

  • Statement: "The acceleration of an object is directly proportional to the net force acting on it, is in the direction of the net force, and is inversely proportional to its mass." Mathematically expressed as F = ma, where F is force, m is mass, and a is acceleration.

  • Significance: Newton's Second Law provides a precise quantitative relationship between force and motion. It allows us to calculate how forces change the state of motion of an object, defining acceleration as the measure of this change. It introduces force as the agent that causes changes in motion and mass as the measure of an object's resistance to acceleration (inertial mass).

  • Powerful Predictive Tool: F=ma is an incredibly powerful tool for predicting and calculating motion in countless situations, from projectile motion to planetary orbits.

  • Still Descriptive Regarding Inertia's Origin: While Newton's Second Law quantifies how forces overcome inertia to cause acceleration, it still does not explain the fundamental origin or nature of inertia itself. Mass is introduced as a proportionality constant, but its deep connection to inertia and the continuation of motion remains unexplained within classical mechanics.
    
    

• Limitations of Classical Mechanics in Explaining Motion and Inertia:

  • Descriptive, Not Explanatory: The primary limitation is the fundamentally descriptive nature of Newton's Laws regarding inertia. They describe what inertia does, and how forces change motion, but not why inertia exists or why motion persists. Classical mechanics provides no underlying mechanism for these phenomena.

  • No Connection to Time or Spacetime: Inertia is treated as an isolated, intrinsic property of matter, with no deeper connection to the fundamental nature of time or spacetime. Classical mechanics operates within a framework of absolute space and absolute time, where inertia is simply "built in" as a fundamental postulate. The deeper relationship between inertia, motion, and the structure of spacetime remains unexplored and unexplained.

1.2. Relativity: Motion as Geodesic Trajectories in Spacetime Geometry

Einstein's theory of relativity, particularly General Relativity, revolutionized our understanding of motion by embedding it within the dynamic geometry of spacetime. Relativity offers a profound geometric description of motion, fundamentally different from the force-based approach of classical mechanics:

• Geodesic Motion: The "Straightest Paths" in Curved Spacetime

  • Principle of Geodesic Motion: In General Relativity, particles, in the absence of non-gravitational forces, follow geodesics – the "straightest possible paths" through curved spacetime. These are the paths that locally minimize or maximize proper time between two events.

  • Inertial Motion as Geodesic Motion: What we perceive as inertial motion (constant velocity in a straight line in classical mechanics) is reinterpreted in relativity as motion along geodesics in flat spacetime (spacetime in the absence of significant gravitational fields). Objects in inertial motion are simply following the "natural" straight paths in the spacetime geometry.

  • Gravity as Spacetime Curvature, Not a Force: Gravity itself is not a force in the Newtonian sense, but rather a manifestation of spacetime curvature caused by the presence of mass-energy. Objects moving in a gravitational field are still following geodesics, but these geodesics are now curved due to the warped geometry of spacetime, leading to what we perceive as gravitational acceleration.
    
    

• Proper Time Maximization: The Temporal Extremum Principle

  • Proper Time (τ) as Intrinsic Time: Relativity introduces the concept of proper time (τ), the time experienced by an observer moving along a specific worldline. Proper time is frame-invariant and represents the actual time elapsed for a moving object.

  • Principle of Maximal Aging (or Extremal Proper Time): In General Relativity, particles, when moving inertially or under the influence of gravity, follow worldlines that maximize (or more generally, extremize) their proper time between two spacetime events. This is a fundamental principle governing motion in curved spacetime.

  • Geodesics Maximize Proper Time (for Timelike Worldlines): For timelike worldlines (paths of objects moving slower than light), geodesics correspond to paths of maximal proper time. Particles naturally follow paths that allow them to "age" as much as possible between two points in spacetime, in the absence of non-gravitational forces.
    
    

• Limitations of Relativity in Explaining Motion and Inertia:

  • Geometric Description, Not Causal Explanation: While relativity provides a beautiful and powerful geometric description of motion, it remains somewhat limited in providing a causal explanation for why particles follow geodesics and why proper time is maximized. Relativity describes how gravity works through spacetime geometry, but the underlying mechanism or reason for this geometric behavior is not fully elucidated.

  • Proper Time Maximization - a Principle, Not a Mechanism: The principle of proper time maximization is a fundamental postulate of General Relativity, and it accurately describes the observed behavior of objects in gravitational fields. However, it is presented as a principle or a mathematical extremum condition, rather than a mechanistic explanation rooted in the fundamental properties of particles and spacetime itself. Why does nature "choose" paths of maximal proper time? Relativity describes that it happens, but not necessarily why.

  • No Microscopic Mechanism for Inertia: While relativity elegantly integrates inertia into the geometry of spacetime, it does not provide a microscopic, mechanistic explanation for inertia at the level of fundamental particles. Inertia is implicitly linked to spacetime geometry, but the underlying reasons for this link, and for the continued motion of particles, remain somewhat geometrically described rather than mechanistically explained.

Conclusion of Section 1:

Both classical mechanics and relativity, while representing monumental achievements in physics, primarily offer descriptive frameworks for understanding motion. Classical mechanics describes motion in terms of forces and inertia, without explaining the origin of inertia. Relativity provides a geometric description of motion as geodesic trajectories in spacetime, but does not fully elucidate why particles follow geodesics or why proper time is maximized. This leaves open the need for a deeper, more explanatory framework that can address these fundamental "why" questions and provide a more mechanistic understanding of motion and inertia, which the Time-Experience Framework aims to provide.

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2. Motion in the Time-Experience Framework

2.1. Directional Proper Time as the Engine of Motion

In the "time-experience" framework, motion is not merely spatial translation over time, but a fundamentally temporal phenomenon driven by the directional flow of proper time along a particle's worldline in spacetime. We posit that proper time (τ) is not just a scalar measure of duration, but embodies a vectorial aspect, a "time flow vector," representing the intrinsic temporal progression of the particle through spacetime. This "time vector" can be represented by the time component of the energy-momentum 4-vector (E/c in SI units, or simply Energy in natural units, denoted as the temporal direction vector).

Imagine proper time as the particle's intrinsic "temporal current" or "directional flow" through spacetime. Motion in spacetime is essentially the particle "riding" or "surfing" along the flow of its own directional proper time. The worldline of a particle is not just a path in spacetime; it is the very manifestation of this directional proper time flow, tracing out the particle's history as it progresses temporally through the four dimensions. This "time flow vector" is the engine of motion, propelling the particle along its worldline.

2.2. Inertia as Resistance to Changes in the Directional Proper Time Flow Vector

Inertia, within this framework, is reinterpreted as the resistance to changes in a particle’s directional proper time experience, specifically, resistance to alterations in its "time flow vector." Instead of viewing inertia as a resistance to changes in velocity in 3D space, we propose it is a more fundamental resistance to changes in the temporal direction of motion in 4D spacetime.

When a force is applied to a particle, it attempts to alter the particle's energy and momentum, and consequently, to deflect or change the direction of its "time flow vector." Inertia manifests as the inherent tendency of the particle to resist these deflections and maintain its current, established directional flow of proper time. It is like a "temporal viscosity" or "temporal friction," a resistance to bending or distorting the particle’s natural, ongoing progression along its temporal path.

Changing a particle’s directional proper time flow vector requires an input of energy and momentum, and inertia is the measure of the energy and effort needed to effect such a change. The greater the inertia, the stronger the particle's tendency to maintain its established temporal direction and resist alterations to its worldline.

2.3. Why Motion Continues: The Stability of Directional Proper Time Flow

The continuation of motion, traditionally described by inertia, becomes a natural and elegant consequence of the particle’s fundamental interaction with spacetime through its directional proper time flow. Once a particle is set in motion, and its "time flow vector" is established along a certain worldline trajectory, there is no inherent mechanism within the Time-Experience Framework to spontaneously alter this directional flow in the absence of external influences.

Imagine a river flowing smoothly in a straight direction. An object placed in the river will naturally continue to flow along with the river current in that direction unless some external obstruction or force diverts its path. Similarly, in the Time-Experience Framework, the particle’s directional proper time flow is the "current" of spacetime itself. Once established, this flow continues unimpeded along a geodesic worldline, representing inertial motion.

Without an external force acting to deflect or redirect the particle's "time flow vector," the particle’s worldline, and thus its state of motion, remains unchanged. Continued motion is therefore not something that needs to be actively enforced; it is the natural, default state of affairs in spacetime, dictated by the inherent stability and persistence of the particle's directional proper time experience. It is changes in motion, deviations from this inertial flow, that require explanation in terms of external forces acting to alter the particle's fundamental temporal progression.

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3. Contrasting the Frameworks

3.1. Classical Mechanics vs. Time-Experience Framework: Addressing the "Why" of Inertia

• Classical Mechanics: The "What" of Motion (Descriptive)

  Classical mechanics, with Newton's Laws, brilliantly describes motion. Newton's First Law, the law of inertia, accurately states what happens: an object in motion tends to stay in motion. Newton's Second Law provides a precise mathematical relationship (F=ma) to calculate how forces change motion. Classical mechanics is incredibly successful in predicting and calculating trajectories, accelerations, and forces in a vast range of everyday scenarios.
  
  

  • Limitations as Description: However, classical mechanics remains fundamentally descriptive. It tells us what inertia is – the tendency to resist changes in motion – but it does not answer the crucial question: Why does inertia exist? Why do objects resist changes in their state of motion? Why does motion continue in the absence of forces? Inertia is treated as a given, an intrinsic, unexplained property of matter. Classical mechanics provides no underlying mechanism or reason for this fundamental behavior.
    
    

• Time-Experience Framework: The "Why" of Motion (Explanatory)

  The Time-Experience Framework, in stark contrast, offers a mechanistic explanation for inertia and the continuation of motion, grounding them in the particle's directional proper time experience. It moves beyond mere description to address the fundamental "why" questions that classical mechanics leaves unanswered.
  
  

  • Inertia Explained by Temporal Resistance: Inertia is not just a given property; it is explained as the inherent resistance to changes in a particle's directional proper time flow vector. This resistance is not arbitrary; it arises from the fundamental nature of particles interacting with spacetime through their temporal dimension.

  • Continued Motion Explained by Proper Time Flow: The continuation of motion is not just stated as a law; it is explained as the natural consequence of the stability and persistence of a particle's directional proper time flow along its worldline. Motion continues because there is an underlying "engine" – the proper time flow – that drives it, and this engine keeps running unless actively disrupted by external forces.

  • Mechanism for Inertia and Motion: The Time-Experience Framework provides a mechanism for inertia and motion, linking them to the fundamental concept of proper time and its directional flow. It's not just describing what happens; it's offering a potential explanation of how and why it happens at a deeper level.

3.2. Relativity vs. Time-Experience Framework: Beyond Geometric Description to Causal Understanding

• Relativity: Geometric Description of Motion (Descriptive)

  Einstein's theory of relativity represents a monumental advancement, providing a profound geometric description of motion and gravity. General Relativity describes motion in terms of geodesics in curved spacetime. Particles follow "straightest possible paths" (geodesics) in spacetime, and in the absence of non-gravitational forces, they move along these geodesics, which we interpret as inertial motion. Relativity beautifully describes how gravity arises from spacetime curvature and how particles move in gravitational fields, maximizing their proper time along geodesics.
  
  

  • Limitations as Geometric Description: However, even relativity, in its standard formulation, remains fundamentally descriptive in certain aspects. While it provides a geometric framework for motion, it doesn't fully explain: Why do particles follow geodesics? Why is proper time maximized along geodesics? What is the underlying  Relativity describes the geometry of motion, but the underlying cause or mechanism for this geometric behavior remains somewhat implicit.
    
    

• Time-Experience Framework: Causal Explanation of Geodesic Motion (Explanatory)

  The Time-Experience Framework builds upon relativity but goes further, offering a more causal explanation for geodesic motion and the maximization of proper time, grounding them in the particle's "time-experience."

  • Geodesic Motion Explained by Maximal Proper Time Flow: The Time-Experience Framework explains why particles follow geodesics: they are naturally following paths that allow them to maintain a stable and maximal directional proper time flow. Geodesics are not just arbitrary geometric paths; they are the spacetime trajectories that are most "natural" and "least resistant" to the particle's inherent temporal drive.

  • Proper Time Maximization Explained by Temporal Engine: The principle of proper time maximization, a cornerstone of relativity, is explained as a consequence of the "proper time flow vector" acting as the engine of motion. Particles naturally tend to follow worldlines that maximize their proper time because that is the path of least resistance for their intrinsic temporal progression. The maximization of proper time is not just a mathematical principle; it reflects a deeper physical tendency for particles to follow their natural temporal flow.

  • Beyond Geometric Description to Causal Mechanism: The Time-Experience Framework moves beyond a purely geometric description of motion in spacetime to provide a more causal mechanism rooted in the particle's "time-experience." It's not just describing the shape of worldlines; it's offering a potential explanation of why worldlines have those shapes and why motion unfolds in spacetime in the way it does.

3.3. Conclusion of Section 3 :

In essence, the Time-Experience Framework offers a significant shift from description to explanation in our understanding of motion. While classical mechanics and relativity provide powerful and accurate descriptions of what motion is and how it behaves, the Time-Experience Framework delves deeper to address the fundamental "why" questions that these frameworks leave unanswered. By grounding motion and inertia in the particle's directional proper time experience, it provides a more mechanistic, causal, and ultimately more satisfying explanation for the enduring mystery of motion and inertia in the universe.

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4. Implications of the Time-Experience Framework

4.1. Deeper Understanding of Motion and Inertia as Temporal Phenomena

The Time-Experience Framework provides a significantly deeper and more mechanistic understanding of motion and inertia, grounding them in the fundamental nature of time itself. By reinterpreting inertia as resistance to changes in a particle's directional proper time experience, we move beyond purely descriptive laws and geometric descriptions to a more explanatory framework that addresses the underlying why of motion.

• Momentum as Temporal Directional Quantity: Momentum, in this framework, is not just a measure of "quantity of motion" in 3D space; it is intrinsically linked to the "time vector" and represents the magnitude and direction of the particle's temporal progression through spacetime. Changes in momentum reflect changes in the directional flow of proper time.

• Energy as Intensity of Time-Experience Flow: Energy is reinterpreted as the intensity or magnitude of the directional proper time flow. Higher energy corresponds to a more intense temporal activity and a greater rate of proper time passage along the worldline.

• Force as Temporal Deflection Agent: Force is understood not as a "push or pull" in space, but as an agent that attempts to deflect or alter the directional flow of a particle's proper time vector. Forces act to change the temporal trajectory of particles, and inertia is the resistance to these temporal trajectory changes.

• Velocity as Manifestation of Directional Temporal Progression: Velocity, in 3D space, is seen as a manifestation of the particle's underlying directional progression in 4D spacetime, driven by its "time flow vector." Velocity is the spatial component of this fundamental spacetime motion, with the temporal component being equally crucial and represented by the "time vector" (E/c or p).

• Acceleration as Change in Directional Proper Time Flow: Acceleration, a change in velocity, is understood as a change in the direction or magnitude of the particle's directional proper time flow vector. Accelerated motion is a state where the particle's temporal trajectory is being continuously altered by external influences.

• Mass as Temporal Inertial Resistance: Mass, particularly rest mass, can be interpreted as a measure of a particle's inherent resistance to changes in its directional proper time experience. Greater mass implies a stronger tendency to maintain its current temporal flow pattern and a greater resistance to external forces attempting to alter its temporal trajectory.

The Time-Experience Framework thus unifies motion, inertia, and proper time into a single, coherent picture, grounding these fundamental concepts in the intrinsic temporal nature of particles and their interaction with spacetime. It provides a mechanistic understanding of inertia, explaining why motion continues and why objects resist changes in their state of motion, in terms of the directional flow of proper time.

4.2. Connection to Gravity as Warped Temporal Flow

By grounding inertia and motion in the particle's directional proper time experience, the Time-Experience Framework also provides a natural connection to gravity. If spacetime curvature is indeed the macroscopic manifestation of propagating particle time-experience, as hypothesized, then gravity itself becomes fundamentally a phenomenon related to the warping and modulation of temporal flow.

Objects in a gravitational field move along geodesics, paths that maximize their proper time in curved spacetime. In the Time-Experience Framework, this geodesic motion can be reinterpreted as particles naturally following paths that allow them to maintain a stable and maximal directional proper time flow within the curved temporal landscape created by massive objects. Gravity is not a force pulling objects through space, but rather a warping of the temporal flow of spacetime itself, guiding particles along paths of least resistance in their temporal progression.

4.3. Elevating Time to Primacy: A Temporal Interpretation of Physics

Ultimately, the Time-Experience Framework elevates time to a position of fundamental primacy in physics. It suggests that motion, inertia, and gravity are not primarily spatial or material phenomena, but are fundamentally temporal phenomena. Physics, in this view, is not just about space, matter, and forces acting in space; it is fundamentally about time, directional proper time flow, and the temporal nature of reality itself.

Time is not merely a dimension alongside space, but the active principle, the "engine of motion," the ground of being from which motion, inertia, and gravity emerge as macroscopic manifestations of the fundamental temporal activity of particles and their interaction with spacetime. This temporal interpretation of physics invites a radical rethinking of our most basic assumptions about the nature of reality and the role of time in the cosmos.

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 5. Conclusion: Towards a Temporal Revolution in Physics

The "Time-Experience Framework" presented in this paper offers far more than just an alternative description of motion; it provides a profound and revolutionary explanation for the enduring mystery of inertia and the continuation of motion. In stark contrast to the fundamentally descriptive nature of classical mechanics and even the geometrically elegant but mechanistically silent framework of relativity, the Time-Experience Framework delves into the underlying causal mechanisms that govern motion, grounding them in the most fundamental aspect of reality: time itself.

By reinterpreting inertia as the inherent resistance to changes in a particle's directional proper time experience, and by identifying proper time flow as the very "engine of motion," this framework achieves a significant paradigm shift. It transcends the limitations of purely descriptive models to offer a deeper, more intuitive, and ultimately more satisfying answer to the age-old question: Why does motion continue? The answer, within this framework, is both elegant and profound: motion continues because particles inherently "experience time," and this directional temporal progression is the very essence of their being and their interaction with spacetime.

This "Temporal Universe" perspective extends beyond just explaining inertia. It offers a unified vision where energy, gravity, spacetime curvature, and the experience of proper time are no longer seen as separate, disparate concepts, but as interwoven facets of a single, underlying temporal reality. Gravity, in this view, is not a mysterious force acting in space, but the macroscopic manifestation of the collective, propagating time-experience of particles, warping the very flow of time and guiding motion along geodesics of maximal temporal progression.

This framework elevates time to a position of primacy, suggesting that physics, at its deepest level, is not primarily about space, matter, or forces, but about time and the temporal nature of existence. It invites a fundamental rethinking of our most basic assumptions, shifting our focus from a spatially-centric worldview to a temporally-centric paradigm where time is not just a dimension, but the driving force, the fundamental engine of motion, and the very ground of being.

The Time-Experience Framework, therefore, is not merely a refinement of existing theories; it is a call for a temporal revolution in physics. It challenges us to move beyond descriptive models and embrace a deeper, more explanatory understanding of motion, inertia, gravity, and the very fabric of reality, grounded in the profound and often overlooked nature of time itself. This framework, while requiring further rigorous mathematical formalization and empirical investigation, offers a new and compelling way to think about the fundamental principles of physics, potentially paving the path towards a more unified and complete understanding of the cosmos.

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