One month to go until we travel out to Sydney and unveil Circa V_02 in the Royal Botanic Gardens, as part of @vividsydney . . . Circa is a twelve-part light sculpture made up of rings that present circannual light levels on earth’s surface. Light is the primary zeitgeber or time giver and is therefore the most responsible factor for setting endogenous clocks in plant and animal life. The arrangement of circles also makes the imperceptible oscillations and feedback loops that occur on a cellular level visible to the human eye. These mechanisms are the basis for the circadian clock that governs some of the behaviour of plants, animals, and humans.