  For over twenty years, the term 'cosmic web' has guided our understanding of
the large-scale arrangement of matter in the cosmos, accurately evoking the
concept of a network of galaxies linked by filaments. But the physical
correspondence between the cosmic web and structural-engineering or textile
'spiderwebs' is even deeper than previously known, and extends to origami
tessellations as well. Here we explain that in a good structure-formation
approximation known as the adhesion model, threads of the cosmic web form a
spiderweb, i.e. can be strung up to be entirely in tension. The correspondence
is exact if nodes sampling voids are included, and if structure is excluded
within collapsed regions (walls, filaments and haloes), where dark-matter
multistreaming and baryonic physics affect the structure. We also suggest how
concepts arising from this link might be used to test cosmological models: for
example, to test for large-scale anisotropy and rotational flows in the cosmos.
