Statistical physics of hair fibre bundles and the shape of a ponytail
Statistical physics of hair fibre bundles and the shape of a ponytail
- Event time: 2:00pm
- Event date: 14th December 2012
- Speaker: Patrick Warren
- Location: CSEC Seminar Room, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Event details
Abstract
There are 100,000 hair fibres on a typical head of hair, hence calculating perceived properties like 'volume' and compressibility are problems in statistical physics. To address this, a density functional theory for the distribution of hair in a fibre assembly has been developed, treating individual elements as elastic filaments with random intrinsic curvatures.
This formalism has been applied to the iconic problem of a ponytail, for which the combined effects of bending elasticity, gravity, and orientational disorder are recast as a differential equation for the envelope -- the ponytail shape equation. Aside from compressibility, this problem is characterised by a single dimensionless measure of the ponytail length, christened the Rapunzel number. From laboratory measurements of model ponytails, the balance of forces in various regions of the ponytail can be identified and related to the measured random curvatures of individual hairs.
Tea and coffee from 15.00.
About Higgs Centre colloquia
The Higgs Centre Colloquia are a fortnightly series of talks aimed at a wide-range of topical Theoretical Physics issues..