When I was a kid, getting stuck in quicksand was a fun imaginary fear. Then the 1980s happened and quicksand went the way of mirrored sunglasses and In Search Of... In this weeks issue of the scientific journal Nature, researchers look at how quicksand swallows people, or rather doesn't. From today's New York Times:
Hit with sudden force from, say, a hapless victim, the quicksand gel turns to liquid. Then salt causes clay particles to stick to one another instead of the sand grains, with the result that a victim ends up surrounded by densely packed sand.Link to NYT article, Link to more info in News@Nature (Thanks, DMD!)
The force needed to pull out a person immersed in quicksand is about the same needed to lift a car, (University of Amsterdam physicist Daniel) Bonn said. The trick for escaping is to slowly wiggle the feet and legs, allowing water to flow in.