Claim:
Humans cannot fully submerge in quicksand without becoming trapped underneath it and submerged completely, hence rating this claim false.
Though quicksand may be an existential terror for moviegoers, some social media users have claimed it’s physically impossible for anyone to fully submerge into its depths.
One Reddit post with over 12,000 upvotes at the time of this writing stated as much in August 2024. TIL that sinking entirely in quicksand byu/valledweller33 intodayilearned is physically impossible
Quicksand has physical properties which allow it to submerge people and other mammals below its surface; however, due to humans being less dense than quicksand it is often physically impossible for a full submersion below quicksand’s surface to take place.
It can be demonstrated through an examination of quicksand properties.
What Is Quicksand? According to the Australian Academy of Science, quicksand is composed of fine sand mixed with microscopic clay particles and water. Left alone, this special mixture will become firmer and viscous over time but sudden pressure changes at the surface may swiftly dissolve it – or upwelling water from underground can break apart hardened compacted layers that might otherwise compact down over time.
These liquid mixtures are known as shear-thinning thixotropic non-Newtonian fluids as they defy conventional rules about solids and liquids, such as toothpaste or hair gel, appearing solid but flowing when subject to pressure or force.
Humans Are Less Dense Than Quicksand
Yield-stress pressure refers to how easily quicksand liquefies from even minor changes in weight; according to researchers conducting a 2005 study. A mere change of just 1% on its surface can liquefy it completely!
Quicksand can act as a trap according to study authors as its instability makes it vulnerable when forced to move, eventually collapsing under its own weight or under greater strain and creating instability that forces bodies caught within it to sink even deeper in. Stress makes the quicksand more liquid; consequently movement by anyone caught within may increase this process further and sink deeper underground.
Reason being, once submerged it becomes difficult to escape due to increasing apparent viscosity or density after weight is applied due to it liquefying due to weight being applied; according to this study.
After liquefaction, quicksand segregates into two distinct phases; water-rich phase and sand-rich one. Viscosity rises due to formation of dense sand sediment with very high volume fraction (ph0.8) and viscosity – this leads to trapping due to difficulty moving densely packed wet sand at an overwhelming density requiring huge forces for movement: for introduction at 1 cms-1 using 10mm pores requires pressure of approximately 106Pa, pulling out one foot takes force of approximately 104 newtons or forces equivalent to lifting medium sized cars from underneath!
Researchers stated it is “impossible” for objects with specific densities – like humans or animals – to completely sink below the surface of quicksand. Quicksand’s density averages roughly two grams per milliliter-1; on the contrary, human densities average roughly half that value.
They reached this conclusion by creating quicksand in a laboratory, placing an aluminum bead that mimics human density on its surface and applying force similar to when someone steps on quicksand – this caused only partial sinkage rather than complete absorption into it.
“Any unfortunate victim could sink halfway into quicksand before finding some comfort knowing there would be no risk of them disappearing beneath its surface,” according to study authors.
Researchers wrote in another article how lab-created quicksand was used to simulate three classic Hollywood quicksand scenes and provide real world comparisons for them.
Quicksand can be likened to thick yogurt that has been stirred. Movement causes it to liquefy and cause collapse of its understructure – creating dense layers of packed sand around your feet which may make escape near impossible without water being added in to dissolve and loosen them up.
Therefore, they deemed myth one — that someone should stay put while trapped in quicksand — true and myth two – that humans cannot escape when fully trapped – true as long as water was added into the mix and “difficult” extraction techniques were implemented to try and extract themselves out.
However, they noted that becoming trapped does not translate to imminent drowning: “[a simple experiment demonstrates] it is almost impossible for humans or animals (including camels ) to sink below quicksand’s surface due to buoyancy forces keeping you afloat].”
To demonstrate their theory, the authors created a figurine called Taz which they custom designed so as to represent both men and mammals with equal density. Once placed inside its container, Taz vibrated back and forth simulating someone moving through quicksand.
“We observe that Taz does indeed sink away, more quickly if we shake harder; however, no matter our best efforts at drowning him completely”, wrote the study authors.
(EuroPhysicsNews) Trapped in Quicksand Can Be Dangerous However, according to study authors of their own work on quicksand’s physical characteristics in river estuaries – where these dangerous environments often exist – many misconceptions regarding drowning or becoming trapped are likely associated with that location of quicksand formation and may contribute to its mythical qualities.
“One may face difficulty when being trapped in quicksand when high tide comes rushing in: in this instance drowning is indeed highly probable,” according to the authors of this research paper.
National Geographic published an interview in 2005 where members of their team stated that simple movements are key in order to escape quicksand.
“To escape quicksand safely and gradually using this technique, wiggle your legs around until a space opens up between your limbs and the quicksand where water can flow down to dilate [loosen] it,” according to study co-author Daniel Bonn’s commentary in Scientific American magazine. You could get out using this approach slowly and progressively as well, according to Daniel.
More serious complications posed by becoming stuck in quicksand include hypothermia, exposure, dehydration or invading tides – such as hypothermia. For further viewing on YouTube:
