Scientific explorations of spirals and convergence phenomena in mathematics, physics, biology, astronomy, computer science and complex systems.
6 articles · Perception
Some images seem to contain spirals or continuous rotation while they are made of circles, segments or static contrasts. These illusions reveal the shortcuts of the visual system.
The circle of fifths organizes keys, harmonics follow frequency ratios and the cochlea is coiled in the inner ear. These three structures are linked to music, but not by a single spiral mechanism.
Linear perspective relies on the convergence of parallel lines toward a vanishing point. In curvilinear perspective, these lines curve. The brain uses these cues to reconstruct three-dimensional depth.
Rotation is present in the ritual practices of all human cultures. Whirling dervishes, shamanic dances and trance rituals use prolonged rotation to induce altered states of consciousness.
Spirals carved in rock appear on every continent since the Neolithic. Is it a universal symbol rooted in human cognition, or an independent convergence toward a naturally salient form?
The semicircular canals of the inner ear detect angular rotations of the head. Vertigo occurs when this system is disrupted, and the nystagmus that accompanies it itself traces a spiral trajectory.