So many cowboy films show people being lost in quicksand, as if being lost in a quickasnd pit meant certain death. In fact, quicksand is subject to the laws of physics. Quicksand is denser than the human body. The laws of physics say that the human body, being less dense than quicksand, will float in quicksand. In fact, the human body is considerably less dense – about half as much - than quicksand, so that if someone were to stand in quicksand, they would only sink up to their wast. Archimedes principle applies here as anywhere – the weight of a body floating in a liquid equals the weight of the liquid that would occupy the volume of the body underneath the surface of the fluid.
The effect is, that as long as the average density of a person is less than the density of quicksand – which is always the case - they will float in the quicksand. Of course the human body is less dense than quicksand. If you get stuck in quicksand, lie flat a crawl out.