The remarkable α-shapes

Summary / Resumen
Recientemente se ha propuesto un método para definir qué moléculas de un líquido están “en” la superficie. Aquí se resume un método alternativo, basado en el concepto de "forma α". A method has been recently proposed in order to define which molecules of a liquid are "on" its surface. Here we present an alternative method, based on the concept of the "α shape".

The problem

Problems in this mathematical field, called computational geometry, have a tendency of being easy to ask ("a children would understand the question"), but hard to answer ("some clever adult is needed + a computer for practical applications"). The quastion is: what is the shape of a set of points?

Application to interfaces

The problem with the liquid surface is precisely, where does it end? This is equivalent to asking what the shape of a set of points (given by the centres of the molecules) is.

Pictures, movie

A snapshot of the system
(click on it for a larger image)

An avi movie showing the concept in action (size, about 8M).

Links

Our manuscript is still in progress.
The α shape does not have a wikipedia entry! Go write one!

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