Driving on the third ring road in Beijing, I felt like was watching a movie in fast-forward.

In the bird embryo these bristles erupt from tiny patches of skin cells called placodes. A ring of fast-growing cells on the top of the placode builds a cylindrical wall that becomes a bristle.

For every boat trip down the Seine or fireworks display, there is a ring nestled in a plate of fried onions or a proposal hastily scrawled on the lid of a fast food container.