Unwinding

I wondered why the sudden, sharp discontinuity in the shell (I think it's real, not a trick of the late summer sunset or the angle of light). I tried googling 'the structure of a snail shell'. Steve Jones, my favourite TV scientist, did his earliest work on snail shells, enough to earn a prestigious undergraduate prize and then an entire PhD. I can see why; I was lost after reading a few paragraphs, and I am none the wiser

Spirals and related forms are among nature's favourite shapes. From galaxies to microscopic organisms, the cavity in your year that enables you to hear, and the pattern of seeds in a sunflower head. The double-helix itself is a spiral form in the broadest sense

And it's a metaphor for a human life: beginning at a point in the centre and unwinding as the decades pass to an ending that - no matter the distance travelled - may not be all that far from the beginning. The sort of ideas that pass through your head when you have seen a new life beginning (or maybe when you are helping to plan an imminent university reunion!)