The 'Cheerios Effect'
Entry by Andrew Capulli, AP225 Fall 2011
Vella, D; Mahadevan, L. "The Cheerios Effect", American Journal of Physics, 73, 817-825. 2005.
As the physics and engineering sciences (all sciences really) have gone increasingly 'nano' in the hopes of addressing fundamental questions in the respective fields, there has been debate over what phenomena are most important (ie what should should we be looking into as scientists?) In this paper "The Cheerios Effect," which appears friendly enough with such a title, the authors address some fundamental questions concerning capillarity and buoyancy using some simple experiments to demonstrate their claims. Why do cheerios or bubbles seem to 'attract' and further, are they really 'attracted' to the side of the bowl or glass? Vella and Mahadevan put the science behind these (and more) phenomena demonstrating the importance of buoyancy of small particles in contrast to the traditional mindset of capillarity dominance.
Capillarity vs Buoyancy: Attraction and Repulsion