Articles

The science

Four pieces on why soft things behave the way they do, written to be read alongside the interactive jelly.

• What jelly actually is

  Collagen unwound into gelatin, then re-tangled as it cools. Why it melts just below body temperature, and why agar behaves nothing like it.

• How firm is a gummy bear

  The Bloom test, what it actually measures, and the four gelling agents that give four completely different textures.

• Why jelly wobbles and steel does not

  Shear wave speed, viscoelasticity, and the scaling rule that makes a big jelly shake more slowly than a small one.

• Round blobs and flat puddles

  The capillary length, why it sits near three millimetres for water, and what changes once the blob is elastic.