There is something powerful and satisfying about things that radiate visually from a centre. It is a motif that recurs in the art of many lands, perhaps because it is always an echo of the universal life-giving sun. Whatever, it is a device that always drags your eyes to the centre of the image, whether this is a flat structure like the spokes of a wheel or the leaves of a fan palm, a more three-dimensional radiation like the stamens of a lily, or an illusion caused by exaggerated perspective like this disturbingly-lit inclined subway.