Take
a piece of wire of length L and move the endpoints
together.
What is the shape of the resulting curve. Experimentally
it
looks somewhat like the silhouette of an icecone. The calculation
should
be done by minimizing the integral of of the square of the curvature
along
the wire. There are various parameters in the problem,
such
as the length L of the curve, and the relative angle at which
the
endpoints meet.
Formulate
the laws of motion of rod in a 2-dimensional
strip.
Iterate numerically. Generalize to the equations
of
motion of a rod between two horizontal plates.
This
problem has important applications in the study
of
granular flow.
This
is a model for avalanches. As the particle falls down
the
staircase, it may eventually stop, accellerate, or exhibit
a
motion with bounded, non-zero velocity. What is the nature
of
the boundary between these types of motion?
Certain
models predict that it is possible to transport
granular
material by depositing it on a vibrating staircase.
The
idea to write the equations of motion for one
particle
on a vibrating staircase, and numerically verifying the
predictions
of these models.
Let
M be a smooth n-manifold with two marked points a and b.
The
mediatrix L is the set of of points x such that the
distance
from x to a equals the distance from x to b.
The
conjecture is that L is locally an "almost" smooth hypersurface
in
M. In particular if M is 2-dimensional, then at every x_0 in L,
L
consists of finitely many spokes, each of which is radially differentiable
at
x_0.
The
following model simulates the dynamics of an earth quake.
Consider
a block placed on a flat surface with friction which is
dependent
on the velocity. A spring is attached to the block.
To
move the block the loose end of the spring is pulled with
a
constant velocity. The force needed to get the block in motion
is
greater than the frictional force, the block will move in
erratic
fashion, similar to the stick-slip motion that occurs between
two
active tectonic plates. The main features of this model are
well-known
but the details of the dynamics of this system
remain
a challenging problem.
This
arises from a problem in statistical physics.
Is
it possible or reasonable for a dynmical system to have
a
measure whose mean appears to move on a strange attractor.
As
we iterate the measure (using the push-forward), does
the
measure itself lie on some attractor?