Is c a perceptual ceiling? A cross-species timing proposal

The speed of light may not be a fixed physical constant but an upper limit on how fast biological brains can process information. This hypothesis suggests that different species, with their unique sensory systems and neural latencies, might perceive light's travel time differently. To test this, the authors propose an experiment comparing human and fly neural responses to light pulses, using Visual Evoked Potentials for humans and calcium imaging for flies. If species register different light-travel times, it would imply that perceptual constraints shape what we call the speed of light. A null result would either confirm its universality or highlight the limits of human instruments for accessing nonhuman perception. The idea invites rethinking physical constants as perceptual boundaries.

Study at a glance

Abstract

This manuscript explores a novel hypothesis: That the speed of light ( c ), rather than being a fixed, observer-independent physical constant, may emerge from the perceptual and cognitive limitations of biological observers. While c is foundational in relativity and modern physics, its measurement is always mediated through instruments and interpreted via human perceptual frameworks. We propose that c represents the upper bound of information-processing speed in biological systems and may not be perceived identically across species with different sensory architectures. To test this, we outline a cross-species experimental design comparing human and fly neural responses to light pulses. Human responses will be recorded via Visual Evoked Potentials, while fly responses will be captured using calcium imaging or extracellular recordings. By accounting for species-specific neural latencies, the experiment aims to isolate whether both species register the same light-travel time. Controls include artificial high-speed sensors, variable environmental conditions, and additional species with divergent visual systems (e.g., mantis shrimp, cephalopods). A positive result-showing interspecies differences in perceived timing-would suggest that c is shaped, at least in part, by perceptual constraints. A null result may confirm c 's universality, or alternatively, reflect the limitations of human-designed instrumentation to access nonhuman perceptual realities. This work has broad implications across physics, neuroscience, and the philosophy of perception. It invites a reconsideration of constants like c as potential perceptual boundaries rather than absolute limits and opens theoretical room for nonhuman or postbiological intelligences to experience physical laws differently. By linking perception and measurement, this hypothesis bridges disciplines and offers a testable framework for exploring the role of the observer in constructing physical reality.