The Universal Law of Poop: Physicists Discover Why Every Turd Coils the Same Way

Scientists have cracked the physics behind the 💩 emoji's iconic swirl — and it's the same force shaping everything from lugworm castings to soft-serve ice cream. Now they're petitioning Unicode for a second emoji.

It's one of those questions you never knew science was trying to answer: why does poop coil?

A team of physicists has now published the definitive answer in Nature Communications — and it turns out every coiled turd, from the emoji on your phone to the castings of a deep-sea lugworm, obeys the same universal physical law.

The mechanism is called elastic rope-coiling theory, a mathematical description of how ropes and similar flexible materials coil when they hit a surface. Most creatures — humans included — release feces downward, which produces the familiar tapered swirl: broad at the base, narrowing to a point as the falling height decreases. It's the same physics that governs soft-serve ice cream, 3D-printed filaments, and even honey drizzled from a spoon.

But the lugworm, a marine creature that lives in U-shaped burrows, defecates upward — and its coils don't taper. Instead they form perfect, uniform spirals. Charles Darwin noticed this peculiarity back in 1881, noting worms defecated "either upwards or downwards with respect to the slope" of their burrows. Now we know why.

The researchers — who tested everything from extrusion rate to muscular control — found that none of the biological factors mattered. The shape is purely physics: material stiffness plus gravity's direction. The lugworm, they concluded, produces what can only be called anti-gravitational poop.

Their confidence in the finding runs deep. The team is now designing a second poop emoji — this one representing the lugworm's non-tapering coil — and plans to formally propose it to the Unicode Consortium.

The discovery builds on a rich lineage of scatological science. In 2021, researchers won the Ig Nobel Prize in Physics for explaining why wombats produce cube-shaped droppings (the secret: alternating stiff and soft regions in the intestinal wall). That paper earned genuine acclaim alongside its comedic award, demonstrating that even the most absurd-seeming questions can unlock fundamental biological and physical principles.

The universal coiling law doesn't just explain what you see in the bowl. It connects animal physiology, gravitational physics, and materials science into a single, elegant framework — one that apparently applies to every creature that's ever left a coil behind.

So the next time you glance at the 💩 emoji, know that you're looking at a direct consequence of elastic rope-coiling dynamics in a gravitational field. Physics doesn't care if you're a human, a worm, or a soft-serve machine. The math is the same.

Sources: Ars Technica, Nature Communications, ScienceAlert