In a sense, sculptures are hymns to gravity. In comparison, painting is almost a virtual art.
Of course, artists of both persuasions have attempted to incorporate elements of the other. Painters like Picasso or de Kooning (see below) and many others have brought a sculptural sensibility to the flat rendering.
Others have strengthened the physical presence of painting by incorporating objects into the canvas or adding layers or blobs of paint or reconstructing the object the painting exists on top of or within. But they cannot quite approach the reality of the typical three-dimensional and naturally weighty sculpture. (Modern metal work emphasizes this aspect to the degree that in some cases “see how heavy I am” appears to be the sole message.)
But weight is comforting. Our sense of touch depends on it. We need resistance to feel something and gravity pulling on a sculpture furnishes plenty of resistance. Even a small figure has an appreciable tug toward the ground.
If a sculpture were weightless it would seem to lose meaning.
This weight also mimics reality in that a sculpture of a human even though possibly much heavier shares with an actual human the basic attribute of having weight and being solid.
However it also implies stasis, inertia and death which is one reason sculpture is so suited to memoria. An unmoving figure is a dead one and also a timeless one.
Antony Gormley’s figures (modeled on himself) at Crosby Beach near Liverpool survive the water which covers them with the tides and though they weather and encrust they persist because they are not alive (more images).
Sculptures and any frozen image intimate death and persistence. And that is another reason why these arts have an impact on us…they are works from an alternate reality or a reality that exists independently of our lives, our time, our ephemeral nature.
Perhaps the ultimate expression of this is Gunther von Hagen’s plasticized humans (more).