The art of dancing is the art of moving the body in a rhythmic fashion, often accompanied by music, to express an emotion or idea or to narrate a story.921 Dance of a sort is common among Earthly animals, usually in connection with courtship activities. Among alien sentients dance will reflect cultural values including love, religion, and community., and may be used as a distinctive mode of communication.3018 Dance may also serve as a vigorous yet sensitive medium of entertainment and recreation, and thus is closely related to sports.
Dance is circumscribed by physiology. The degree of movement that is physically possible is determined by the flexibility and strength of muscles, ligaments, and the bony frame. The least flexible part of the body is the skeleton. As one writer describes humans:
The structure of bones and joints governs the amount of bodily movement in any one direction. The ribs and chest can easily be bent to each side and forward but will not bend backward. The ball and socket structure of the shoulder and hip joints permits a small degree of movement. Movement from the hip is easier in a forward direction; it is more difficult to swing the leg up to the side or the back than in front of the body. The ballet dancer must practice until his legs can be raised high in all directions without loss of balance or control. A fundamental of dancing is the control of distribution of weight.921
This description will be quite different for extraterrestrials. Other creatures will have alternative limb structures that permit the alien body to flex in unexpected ways. To the author’s eyes, even the very best human ballet always seems somewhat awkward and undignified. Perhaps this may be chalked up to man’s evolution on the grassy savannahs of prehistoric Africa. But compared to intelligent octopoid dancers with totally flexible limbs, human performers must appear as clumsy lock-kneed oafs.
Creatures connected together with universal jointed skeletons should also prove superior in solo ballet performances. Weird internal structures will permit odd forms of dance which are physically impossible for human beings to emulate. This may result in artistic culture shock among human choreographers and artists, who may undergo intricate surgical operations and skeletal modifications simply to be able to appreciate first hand the alien mode of emotive dance. Performances under conditions of low gravity (Moon or Mars) or in empty space3018 also should prove strikingly graceful -- something like underwater ballet, but without the viscous medium.
What can we say about sports? Multispecies athletic competition such as an Interplanetary Olympics would be complicated by the gravity factor. ETs native to high-gravity worlds would have a natural advantage, since in any given mass class these beings will have more muscle per kilogram than the others. It is an open question whether the gravity-related physiological differences between alien races will or should be compensated during scoring. Although the aggressive-discharge model of sports activity in humans has now been disproven,1804 other sentient races may use athletics to drain off pent-up emotional energy. Such creatures may instinctively regard compensatory scoring as unfair or unnecessary.*
* Much has been written about the effects of planetary surface gravity on various sports events, especially track and field, as for example Eck,1350 Lafleur,138 Margaria,3019 and Richardson.558