We Never Experience the Present: A Layered Lookback-Time Framework of Physical and Neural Delays

Human experience feels instantaneous, yet every perception involves a chain of physical and biological delays. Light travels from an object to the eye at a finite speed, followed by visual signal processing in the retina and brain. This paper presents a layered framework for understanding perceptual lookback time by combining physical light-travel delay and neural processing delay. It examines examples ranging from everyday objects, such as mobile phones and nearby people, to astronomical objects such as the Moon, the Sun, and distant stars. The analysis demonstrates that for everyday visual experiences, neural processing delays dominate over the extremely small physical light-travel delays. At astronomical distances, however, light-travel time becomes significant, allowing us to observe celestial objects as they existed in the past. The paper also discusses predictive processing in the brain, the concept of simultaneity in special relativity, and the relationship between perception and the present moment. This work is a review and theoretical synthesis based on established findings in physics, astronomy, and neuroscience. It proposes a simple quantitative framework for understanding why human perception does not provide direct access to an instantaneous present.