The motion of oscillation...introduces temporal pulse in living organisms, and is its basic pulse, or measure. Indeed, it can perhaps be said that internal temporal organisation is a fundamental requirement, as well as symptom, of life. Trying to answer the question posed by Erwin Schrodinger, which was simply 'What is life?', a mathematician, Jonathan D. H. Smith, posits that 'biological systems' are 'systems complex enough to isolate their component space-times' -- in other words, to structure the indeterminate flow of time and space through internal dynamics. Organisms are highly organised forms, and the internal structuring of time through regular motion seems to be among the earliest and most universal features of organic life. This, in fact, corresponds to what we actually know through simple observation: living organisms are entities which move of their own accord, while inanimate matter moves only under the application of external force. The measurement of organic time through oscillation also echoes philosophical intuitions dating back to Aristotle, who thought that time is the measure of motion ('the numeration of continuous movement').-- from Time by Eva Hoffman
via The Book of Barely Imagined Beings
