>It is impossible for a human to sink entirely into quicksand,[2] due to the higher density of the fluid. Quicksand has a density of about 2 grams per cubic centimeter, whereas the density of the human body is only about 1 gram per cubic centimeter. At that level of density, sinking beyond about waist height in quicksand is impossible. Even objects with a higher density than quicksand will float on it if stationary. Aluminium, for example, has a density of about 2.7 grams per cubic centimeter, but a piece of aluminium will float on top of quicksand until motion causes the sand to liquefy.[3]
>Quicksand is a trope of adventure fiction, particularly in film, where it is typically and unrealistically depicted with a suction effect that causes people or animals that walk into it to sink until fully submerged and risk drowning. This has led to the common misconception that humans can be completely immersed and drown in quicksand; however, this is physically impossible.[7] According to a 2010 article by Slate, this gimmick had its heyday in the 1960s, when almost 3% of all films showed characters sinking in clay, mud, or sand.[8]