The sky is the perceptible outer space that can be perceived from the Earth and from
any other celestial body but at the same time it is hemispheric and seems to limit upward vision.

It is etymologically derived from the Latin coelum or caelum, depending on the forms, and these appear to be related respectively to the greek κοῖλος (koilos) with the meaning of cable, sunken, and refers to a ku-root with the sense of being convex (comparable to the Italian saying “volta celeste”); or to the verb caedo, that is to cut, since the astrologers scholastically divided the sky into regions.

The ancient philosophers understood the sky in different ways, for example according to the Greek philosopher Aristotle, celestial bodies are formed by an incorruptible substance that he calls “ether,” a crystalline element with which the universe is made, and from which he claimed the human mind was also formed. And it is ether that plays a central role here: from the ancient greek αἰθήρ, which flowed into Latin as aether, synonymous with quintessential (from medieval Latin quinta essentia in turn a variation of the the greek pémpton Stoicheion, fifth element), was an element which was added to the four that were already known, that is, fire, water, earth and air. Moreover, the greek 
philosopher Plato, in regard to perfect lands inhabited by superior beings, and located above the earth on which his feet rested, argued that the ether had the shape of a dodecahedron, in other words of a Platonic solid composed by twelve faces whose numerological meaning also implied a 
correspondence with the twelve signs of the zodiac.

Therefore, you could metaphorically consider the wall sculptures of Indriķis Ģelzis, mainly made of steel tubes adorned with various kinds of fabrics and different colors, as “platonic solids" made of symmetries, edges and vertexes. These sculptures exist in a state in between the conception of the ancient philosophers who lookedto the sky considering it the highest, clearest and most pure of the starry celestial space and the more recent conception in which space is intended as a place of electromagnetic wave propagation, for broadcasting. They remain perpetually poised between opening and limit, perimeter and spill. The conception of a sky understood as non-addition becomes full of references and manifests itself in the structure of these works that delineate negative spaces, real exhortations to the sky which from time to time are dressed as the land. 

*various sources.

Domenico De Chirico