Looming

Looming is a term found in the study of perception, as it relates directly to psychology. Looming occurs when an object begins moving closer to the eye. As the resulting image becomes increasingly larger on the perceiver's retina, i.e., when an object looms, there is an automatic physiological response to perceive the object as an approaching object or surface, instead of one that is or receding. This sensory cue is key for collision avoidance and predator detection. A wide range of animals, including both invertebrates and vertebrates, are sensitive to looming stimuli, and looming-detection systems are present in the earliest days of life, highlighting their ecological importance. Evidence indicates that looming perception is not limited to the visual modality, but can occur due to auditory or even tactile stimuli.

In The Black Cloud, Sir Fred Hoyle evidenced for the first time a relationship between the object expansion and the time to collision.