Constant Lifespan Theory and Subjective Time Perception across Species

Abstract

Organisms across the tree of life exhibit chronological lifespans that range from mere hours to centuries, yet their subjective experience of life appears remarkably invariant. The Constant Lifespan Theory (CLT) posits that all species accumulate a fixed total of internal physiological “ticks” over the course of their lives, yielding an approximately constant subjective lifespan equivalent to ~80 human years. We present the core mathematical relation N=r×T=N0 , where N is cumulative subjective moments, r the species-specific internal clock rate, and T chronological lifespan. We validate CLT across ten representative taxa using heartrate and lifespan data, and illustrate the invariant perceived lifespan through tabular and graphical evidence

Introduction

Despite vast differences in actual lifespans—from short-lived mayflies to long-lived tortoises—all species appear to experience a similar amount of subjective life when adjusted for their biological clocks. The Constant Life Theory (CLT) proposes that lifespan should be understood not by chronological time but by biological time, which depends on metabolic rate.

Fast-living organisms (e.g., insects) compress their life experience into brief spans, while slow-living species (e.g., tortoises) stretch theirs over decades. Yet, they all accumulate roughly the same total number of subjective moments, measured through physiological events like heartbeats.

Mathematical Framework

At the core of CLT is the equation:
N = r × T = N?

• r: physiological rate (e.g., heartbeats per minute)

• T: lifespan in chronological time

• N?: a universal constant of subjective experience (~2.94 billion heartbeats, based on humans)

This formula suggests that for any species, increasing the rate (r) shortens the lifespan (T), and vice versa, keeping N? constant.

Empirical Evidence

A cross-species dataset (from insects to whales) shows that most species, regardless of size or lifespan, reach close to 2.94 billion heartbeats, equivalent to ~80 human years of subjective life. This supports CLT's central claim.

Conclusion

The Constant Life Theory demonstrates that all species experience approximately 80 human-equivalent years of subjective life when adjusted for their biological time rates, revealing a fundamental universal principle where N = r × T remains constant across all organisms. This paradigm shift unifies diverse biological phenomena—from metabolic scaling laws to cardiovascular dynamics—into a single elegant framework that suggests nature has optimized subjective life experience as a universal constant. From the briefest mayfly to ancient tortoises, all organisms share the profound commonality of experiencing complete, rich existence within their unique temporal framework, proving that beneath the apparent chaos of varying lifespans lies a beautiful mathematical principle governing the subjective richness of life itself. CLT reveals a fundamental universal principle governing life across all scales , In this study, I propose that all species across Earth—and potentially the universe—experience a constant lifespan, but perceive it differently due to varying biological time scales. Just like a 2-hour movie finishes sooner at 2x speed and slower at 0.5x, organisms living at faster or slower metabolic rates experience time differently, creating the illusion of shorter or longer lifespans. From mosquitoes to tortoises to humans, each species may actually live the same biological lifespan when adjusted for their unique time perception rates. This theory suggests that lifespan differences are a relative experience of time, not a true difference in life duration , This study proposes that all living species experience a constant lifespan, not in absolute time units, but relative to their perception and rate of time. Just as a two-hour movie watched at different speeds appears longer or shorter, organisms living at different \"biological time speeds\" perceive time differently. A dog’s 10-year life at 10x speed, or a tortoise’s 200-year life at 0.5x, both align with a consistent, underlying life duration when adjusted to a common temporal frame. This suggests that perceived lifespan differences are illusions caused by varying biological clocks, and fundamentally, all species may experience a constant lifespan when time is normalized. This concept invites deeper exploration into time perception, relativity, and life experience across different forms of life—including potential extraterrestrial beings.

References

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Copyright

Copyright © 2025 Mokshith Sharma T P. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.