Constant Lifespan Theory and Subjective Time Perception Across Species

We propose the Constant Lifespan Theory (CLT), an original hypothesis stating that all species experience a subjectively constant lifespan, even though their objective lifespans vary greatly. In this view, each organism's internal clock ticks at a rate inversely proportional to its lifespan, so that the total number of “subjective moments” (ticks) per life is roughly the same across species. This idea is supported by evidence from neuroscience and biology: small, fast-metabolizing animals perceive visual flicker at much higher rates than larger animals ‘ , implying they live in “slow motion” relative to us. For example, flies can resolve light flickering up to ~300 Hz while humans resolve only ~65Hz  , suggesting flies see more events per second. Similarly, classic biology finds that many mammals have a nearly constant total number of heartbeats or respiratory cycles in a lifetime  . We synthesize these findings into a mathematical model: if an organism with lifespan T’ processes internal clock ticks at rate r , then N = rT (total ticks) is approximately constant across species. This yields the prediction that subjective time scales linearly with metabolic/ processing rates. We discuss supporting data (flicker-fusion thresholds, heart/respiration rates, metabolic scaling) and implications for cross-species cognition. The CLT offers a unified framework linking physiology and perceived time, with potential applications from ecology to aging research.