HR: 1340h
AN: ED13C-1149 [Abstracts]
TI: A Home Made Lava Lamp That Demonstrates Thermochemical Convection in Action and is Unlikely to Cause
Fatal Injuries to Students
AU: * Moresi, L
EM: louis.moresi@sci.monash.edu
AF: School of Mathematical Sciences, Monash University, Clayton, Vic 3101
Australia
AU: Farrington, R
EM: rebecca.farrington@sci.monash.edu
AF: School of Mathematical Sciences, Monash University, Clayton, Vic 3101
Australia
AU: Moradi, H
EM: hamed.moradi@sci.monash.edu
AF: School of Mathematical Sciences, Monash University, Clayton, Vic 3101
Australia
AU: Kiel, P
EM: pkiel@astro.swin.edu.au
AF: Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Vic 3122
Australia
AB:
It can be quite difficult to instill an intuitive sense of the scaling relationships for mantle convection to a class of
geology students, but the use of various props can help. One favorite demonstration tool is the good old lava lamp which,
coincidentally, first went on sale at the very time plate tectonic theory was gaining acceptance.
Armed with one or more lava lamps, a lecturer can quickly impress upon students how scaling effects such as viscosity, heat
input, gravitional acceleration influence the vigour of convection - a first step to understanding basic concepts such as
Rayleigh number from a non-mathematical perspective.
For more advanced students it is instructive to build a lava lamp for themselves because then it is necessary to understand
the trade-off between chemical and thermal buoyancy, and how the equivalent scaling relationships to the purely thermal
convection case play out.
However, most of the recipes for lava lamps which you can find on the web involve the use of highly toxic substances, often
flammable, and suggest the use of mains electricity to provide the light and heat. Needless to say, university safety
officers and concerned parents are nervous about permitting such activities in student offices, dorms or at home. We share
their concerns, of course, and here suggest a number of relatively safe alternatives which can be constructed from
supermarket foodstuffs and cosmetic products together with heat sources such as a cappucino machine, a laptop running finite
element simulations, as well as sealed chemical handwarmers.
DE: 8110 Continental tectonics: general (0905)
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8121 Dynamics: convection currents, and mantle plumes
DE: 8130 Heat generation and transport
SC: Education and Human Resources [ED]
MN: Fall Meeting 2005