Why do your fingertips go wrinkly in water?
This soaking makes the outermost layer of skin double or triple in size as its cells swell, causing our skin to buckle and wrinkle.
However as we age, our skin becomes thinner so even though this outer layer still swells just as much, there is less of it to start with and therefore less wrinkling.
The reason skin gets wrinkly instead of simply dissolving away is because of the complex structure of a protein called keratin in the outermost layer of skin cells, says mathematician and physicist Dr Myfanwy Evans, from the University of Erlangen-Nrnberg in Germany.
The keratin filaments in these outermost dead cells called corneocytes are arranged in a kind of fibrous weaving.
"They form this lovely geometric array of fibres and using this specific geometry you can get really nice mechanics about how the corneocyte expands, fills with wa ...more