PHYSICAL MATHEMATICS SEMINAR


TOPIC:		RIPPLING INSTABILITY OF A COLLAPSING BUBBLE

SPEAKER:	RAVA DA SILVEIRA
		Harvard University


ABSTRACT: 

Viscous liquid bubbles burst much slower that soap bubbles. For a high
enough viscosity, a bubble bursts by collapsing under its own weight and
folds into a wrinkled structure reminiscent of the eye's iris - an effect
first observed by Debregeas, de Gennes, and Brochard-Wyart in 1998.  In
fact, such a \emph {rippling instability} occurs both for \emph {elastic}
(solid) and \emph {viscous} (liquid) films. I shall present a simple
theory for the elastic case, then extend it to the viscous case.
Preliminary experimental results are in good agreement with the
predictions, which differ from the outcome of a (more naive) scaling
analysis. Indeed, the phenomenon is of an essentially \emph {geometric}
nature, a key point which will be discussed in some detail

DATE:		TUESDAY, OCTOBER 24, 2000

TIME:		2:30 PM

LOCATION:	Building 2, Room 338


Refreshments will be served at 3:30 PM in Room 2-349

Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA  02139