"The spiral is a spiritualized circle. In the spiral form, the circle, uncoiled, has ceased to be vicious; it has been set free."
—Nabokov

I think time moves in a spiral. I think spirals are the most recurring form in the universe.
DNA are the smallest spirals and galaxies are the biggest. “In mathematics, a spiral is a curve which emanates from a point, moving farther away as it revolves around the point. It is a subtype of whorled  patterns, a broad group that also includes concentric objects.” The Wikipedia page is very interesting because it teaches you about different types of 2D and 3D spirals, as well as the history of the form.
Below is are some diagrams showing some of these types, as well as an image of Robert Smithson’s “Spiral Jetty,” and one of Louise Bourgeois’ many spiraled prints.