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Is quicksand actually as dangerous as advertised? Nope. Quicksand—that is, sand that behaves as a liquid because it is saturated with water—can be a mucky nuisance, but it’s basically impossible to die in the way that is depicted in movies. That’s because quicksand is denser than the human body.
- The Editors of Encyclopaedia Britannica
- Overview
- Floating in Quicksand
- Difficult to Get Out Of
- What to Do When You're Stuck
- Origins of the Myth
If stumbling into quicksand ranks on your list of worries, don't panic. A new study suggests that quicksand is not as deadly as it may seem.
If stumbling into quicksand ranks on your list of worries, don't panic. You won't sink in—at least not all the way. Real quicksand is certainly hard to get out of, but it doesn't suck people under the way it always seems to in the movies.
According to a study published in the current issue of the journal Nature, it is impossible for a person immersed in quicksand to be drawn completely under. The fact is, humans float in the stuff.
Researchers in the Netherlands and France studied quicksand, a combination of fine sand, clay, and salt water. At rest, quicksand thickens with time, but it remains very sensitive to small variations in stress.
At higher stresses, quicksand liquefies very quickly, and the higher the stress the more fluid it becomes. This causes a trapped body to sink when it starts to move.
But a person moving around in quicksand will never go all the way under. The reason is that humans just aren't dense enough.
Quicksand has a density of about 2 grams per milliliter. But human density is only about 1 gram per milliliter. At that level of density, sinking in quicksand is impossible. You would descend about up to your waist, but you'd go no further.
Even objects with a higher density than quicksand will float on it—until they move. Aluminum, for example, has a density of about 2.7 grams per milliliter. But a piece of aluminum will float on top of quicksand until motion causes the sand to liquefy.
During their study, researchers placed an aluminum bead on top of a container of laboratory-created quicksand. At rest, the bead remained on the surface, despite aluminum's higher density.
But then scientists started shaking the container. When they shook it only a little, the bead stayed floating on top. But when they shook the container a bit harder, the ball descended to the bottom.
But if quicksand becomes less viscous as you struggle, why is it so difficult to escape? The reason, explain the study's authors, is that after its initial liquefaction, quicksand's apparent viscosity (thickness or flow resistance) increases.
The increase is due to the formation of sand sediment, which has a very high viscosity. It's the difficulty of moving this dense sand that causes the problem.
If you do step into quicksand, says study co-author Daniel Bonn, you'll only sink in a little deeper than your waist. "I would say there would be some pressure on the chest, but not enough to cause serious trouble."
So how do you get out? Don't ask your friends to tug on you; they're likely to pull you "into two pieces if [they] try hard to pull [you] out," said Bonn, a physics professor at the Van der Waals-Zeeman Institute at the University of Amsterdam.
A person will gradually begin to sink in quicksand, and movement will make the victim sink faster. This may be the origin of the advice to "never struggle if you're caught in quicksand."
But no amount of struggling will send you in over your head. Bonn suggests that it isn't struggling that can get you into trouble, but getting caught in quicksand near the sea, which is generally where quicksand is found.
26 de ene. de 2022 · There is also a very dangerous natural form of what is commonly referred to as quicksand that can, and often does, kill people. This is something called liquefaction.
- Christopher Mcfadden
29 de mar. de 2016 · The quicksand effect means that falling into a silo full of grain can often be fatal (Credit: Getty Images) In the lab Bonn’s team found that salt was an essential ingredient because it...
8 de sept. de 2021 · Why do we get stuck in quicksand then? Quicksand is an example of physics at play. Daniel explains the clay in the Iranian quicksand helps to create a matrix that stabilises a loose packing of sand grains in saltwater.
Quicksand (also known as sinking sand) is a colloid consisting of fine granular material (such as sand, silt or clay) and water. It forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that loses strength and cannot support weight.
19 de nov. de 2022 · Many think of quicksand as being able to engulf humans whole in a matter of a seconds, but does it work that way? Quicksand is formed by sand becoming saturated with water and put under...
