請問甚麼是[Ouroboros]?

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1478 drawning by Theodoros Pelecanos, in alchemical tract titled Synosius.
The Ouroboros, also spelled Oroborus, Uroboros or Uroborus (IPA: [ˌjʊərəʊˈbɒrəs]), is an ancient symbol depicting a serpent or dragon swallowing its own tail and forming a circle. It has been used to represent many things over the ages, but it most generally symbolizes ideas of cyclicality, primordial unity, or the vicious circle. The ouroboros has been important in religious and mythological symbolism, but has also been frequently used in alchemical illustrations. In the last century, it has been interpreted by psychologists such as Carl Jung as having an archetypal significance to the human psyche.
The name ouroboros (or, in Latinized form, uroborus) is Greek οὐροβóρος, "tail-devourer". The depiction of the serpent is believed to have been inspired by the Milky Way, as some ancient texts refer to a serpent of light residing in the heavens. [citation needed]
Overview
Plato described a self-eating, circular being as the first living thing in the universe-- an immortal, perfectly constructed animal.

"The living being had no need of eyes when there was nothing remaining outside him to be seen; nor of ears when there was nothing to be heard; and there was no surrounding atmosphere to be breathed; nor would there have been any use of organs by the help of which he might receive his food or get rid of what he had already digested, since there was nothing which went from him or came into him: for there was nothing beside him. Of design he was created thus, his own waste providing his own food, and all that he did or suffered taking place in and by himself. For the Creator conceived that a being which was self-sufficient would be far more excellent than one which lacked anything; and, as he had no need to take anything or defend himself against any one, the Creator did not think it necessary to bestow upon him hands: nor had he any need of feet, nor of the whole apparatus of walking; but the movement suited to his spherical form was assigned to him, being of all the seven that which is most appropriate to mind and intelligence; and he was made to move in the same manner and on the same spot, within his own limits revolving in a circle. All the other six motions were taken away from him, and he was made not to partake of their deviations. And as this circular movement required no feet, the universe was created without legs and without feet."[1]
In some representations the serpent is shown as half light and half dark, echoing symbols such as the Yin Yang, which illustrates the dual nature of all things, but more importantly, that these opposites are not in conflict. In alchemy, the ouroboros symbolises the circular nature of the alchemist's opus, which unites the opposites: the conscious and unconscious mind. It is also often associated with Gnosticism, and Hermeticism.
The Ouroboros often represents self-reflexivity or cyclicality, especially in the sense of something constantly re-creating itself, the eternal return, and other things perceived as cycles that begin anew as soon as they end. It can also represent the idea of primordial unity. The Jungian psychologist Erich Neumann writes of it as a representation of the pre-ego "dawn state", depicting the undifferentiated infancy experience of both mankind and the individual child.[2]
The Ouroboros could very well be used to symbolize the closed-system model of the universe of some physicists. The organic chemist August Kekulé claimed that a ring in the shape of Ouroboros that he saw in a dream inspired him in his discovery of the structure of benzene. As noted by Carl Jung, this might be an instance of cryptomnesia.

Historical representations
The Ouroboros is one of the oldest mystical symbols in the world. The serpent or dragon appears in Aztec, Chinese, and Native American mythologies, among others.

The Ouroboros is a Greek word which means "tail swallower." The ouroboros is usually depicted in the form of a snake swallowing its tail and is usually circular; although it is sometimes depicted in a lemniscate shape.

In your case, it may mean that the world is on-going.
Hope this helps.