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A mechanism placed inside a cylinder turns a steel rod at the end of which a white helix rotates freely.

This double rotation, of the rod through 360° and of the helix on itself, creates a global movement on which the Synthetic Light is projected.

Bands of colour appear in mid-air, in the colours that make up the beam of Synthetic Light.
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http://www.pierofogliati.it/svolazzatore-cromocangiante/?lang=en (30.08.2022)

Synthetic Light (1965)

During the 1960s, Fogliati worked on the development of his urban projects. He wanted to introduce aesthetic presences into the environment and to act on atmospheric events in unusual ways. One of these was the colouring of rain.

Instead of trivialising the idea with simple beams of coloured light, Fogliati intended to create a truly unusual event with a light that “behaved in a ‘particular’ way”. In the mid-1960s, he designed and produced a type of light he called Luce Sintetica, Synthetic Light, or Luce Fantastica, Fantastic Light.

When the light is used to illuminate a motionless object, the beam appears to be white. When the light illuminates a moving object, then it breaks down into its constituent colours.
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http://www.pierofogliati.it/svolazzatore-cromocangiante/?lang=en (30.08.2022)