Vertical sinusoidal forcing of glycerin-water establishes periodic surface waves. With increased forcing, the solution reaches a quasi-periodic state of various wave heights. Under even higher amplitude, jets can be produced. These jets are examples of singularities, defined by a diverging velocity gradient. Difficulties in modeling the surface arise from nonlinear boundary condition equations.

Read a Letter to Nature: "Singularity dynamics in curvature collapse and jet eruption on a fluid surface"
http://www.nature.com/nature/j ournal/v403/n6768/full/403401a 0.html

Visit the Lab:
http://complex.umd.edu/

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Vortex rings were propelled towards each other at varying impact parameters.
Different behaviors can be observed as impact parameter is changed. At small impact parameters, rings expand and rotate due to the collision. As impact parameter increases, rings pass by each other producing instability.

For more information about this and other experiments in Dan Lathrop's Lab at the University of Maryland, visit http://complex.umd.edu

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The Three Meter Geodynamo experiment is the latest in a series of progressively larger experiments in the Lathrop Lab at the University of Maryland to study how planets generate magnetic fields. We are essentially trying to build planetary cores in the lab.

We hope the Three Meter experiment will generate a magnetic field from a rotating turbulent flow of liquid sodium metal.

The experiment is now in an assembly and testing phase.

When complete it will contain nearly 13 tons (13,000kg) of sodium metal flowing in the space between a 3 meter diameter outer sphere (shown here in a rotation test) and a 1 meter diameter inner sphere concentric with the outer. Each sphere has a 350 horsepower (250kW) electric motor to drive its rotation. The inner sphere models the Earth's solid inner core; the sodium models the Earth's fluid outer core, the source of the Earth's main magnetic field.

For more information on this experiment and other experiments at Dan Lathrop's lab at the University of Maryland, please visit http://complex.umd.edu

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