We describe a low-cost yet experimentally challenging method to measure the acceleration of gravity,
g , using a liquid in a rotating bowl and a laser pointer. The idea underpinning this novel method
is that the rotating liquid surface will form a parabolic reflector which will focus light into a
unique focal point. By measuring the height of the focal point, g could be determined to ##IMG##
[http://ej.iop.org/images/0031-9120/51/5/053004/pedaa27f0ieqn001.gif] {$9.78\pm 0.13$} m s −2 . We
discuss the pedagogical merits of this method compared to more traditional methods for measuring g ,
and how it can be implemented as an experimental problem at different educational levels.