Where is the most sucking swamp. Why does the swamp suck? How a swamp is formed

The swamp that sucks is called, quagmire. It can only pull in living objects. The bog is formed on the basis of lakes by overgrowing with a green carpet of moss and algae, not in all swamps.

A swamp swamp is formed on the site of a lake. Lilies, water lilies and reeds on the surface of the lake grow over time into a dense carpet on the surface of the reservoir. At the same time, algae grow at the bottom of the lake. As the cloud of algae and moss forms, it rises from the bottom to the surface. Due to the lack of oxygen, rotting begins, organic waste is formed, dispersing in the water and forming a bog.

The bog sucks in living objects. This is explained by its physical properties. The bog belongs to the class of Bingham liquids, physically described by the Bingham-Shvedov equation. When they hit the surface of an object with a small weight, they behave like solid bodies, so the object will not sink. When an object has a large enough weight, it sinks.

There are 2 types of immersion: under-immersion and over-immersion. The behavior of a body that has fallen into a liquid is subject to the ratio of the influence of gravity and the buoyant force of Archimedes. The body will sink into the quagmire until the strength of Archimedes equals its weight. If the buoyancy force is less than the weight, then the object will be underloaded; if it is greater, then the object will be overloaded.

Why are only living objects subject to reloading?

This is because such objects are constantly moving. What if it freezes? Will the dive stop? Alas, this will only slow down the immersion, because a living body always moves because it breathes. Inanimate objects remain motionless, so they do not completely sink.

Overloading into a quagmire is the suction of a swamp. Why does the movement of the body accelerate the immersion? Any movement is the application of a force that increases the force of pressure on the support. It is due to the weight of the object and the force of gravity. Sudden movements are the reason for the formation of areas of low pressure under the body. These areas will lead to an increase in atmospheric pressure on a living object, which will further submerge it.

So, physical definition The word “sucking in a swamp” looks like this: Bingham’s liquid (quagmire) tries to transfer a living object that has fallen into it to a level below normal immersion, at which the Archimedes force is less than the body.

The suction process is irreversible. A drowned body, even after the cessation of life, will not emerge.

How not to get sucked into the swamp

The probability of being drawn into a swamp increases in summer and autumn, this practically does not happen in winter, as it freezes surface layer, as a result of which it becomes very durable and it is very problematic to go under it. Therefore, it is in the summer and autumn periods that you need to be extremely careful and look under your feet when you are in such an area. As a rule, swampy areas occupy a large space in which there are islands, you can cross a given area along them, but sometimes a seemingly solid layer of earth turns out to be a real quagmire.

Suck into the swamp can instantly or gradually. If the swamp is very deep, then the person is sucked in instantly, it is impossible to get out of such a swamp if there is no person nearby who could provide help. If it sucks gradually, then there is a chance to get out of the abyss on your own. But this will require knowledge of some rules.

Rules to know if there is a chance of getting into a swamp

The main rule that everyone needs to know is not to make any sudden movements when you are in a swamp. If in a swamp sucks slowly, there is every chance to escape.

First of all, once in a swampy area, you need to get a stick, it is desirable that it be wide and strong, that is, a real bar. This stick can be your salvation, so you need to choose it carefully, and not take the first knot that comes to hand. If you find yourself in a swamp, slipping off a bump, then you will most likely be sucked in quickly, because by inertia you will continue to move, thereby helping the bog, therefore it is better to fall on the stomach or back, so you will be sucked in much more slowly.

If you do not go under water too quickly and you have a stick, then it should be carefully placed in front of you, well, if the nearest stronghold is not more than half a meter, then the end of the stick will fall to the ground and it will be easier for you to get out. But even if the stick is completely in the swamp, you need to cling to it and try to transfer your center of gravity to this stick, so you get a kind of bridge and you can get out on land or wait for help without risking to completely go into the silt.

If you have absolutely nothing at hand that could serve as your leverage, try to take a horizontal position. Do this as carefully as possible, carefully shifting your center of gravity from your legs to your torso, if you manage to do this, then your body weight will decrease significantly and you will no longer be dragged into the swamp. In this position, you can wait for help. But, being in a swamp, in no case should you make sudden movements, wave your arms and try to pull your legs, this will suck you in the abyss even more. Being in such a position you can’t even shout loudly, calling for help, and even more so to swing free limbs. If the top of your body is still free, then you need to take off your jacket or raincoat and throw it on the surface of the swamp, you can also get out on it, it will not allow the swamp to suck you in.

If it sucks into the swamp very quickly, then only an outsider can help, he must throw a rope or a stick, along which a person who has fallen into a swamp could get out to a hard surface. Sometimes, in order to pull one person out of the swamp, at least three people are required on land, since the suction force of the swamp is very high. It should also be remembered that if a person is pulled from a swamp, then under no circumstances should he be released. to take a breather, a slightly released person will instantly go into a quagmire, receiving additional energy from the land during repulsion.

horse rescue

Rescued only with the help of technology

This is how a horse was rescued in Australia. Technology helped again

On Avalon Beach in Australia, rescuers tried for several hours to pull a horse stuck in a bog up to its neck.

The owner of the horse, Nicole Graham, along with her seven-year-old daughter Paris, set off for the usual afternoon horse ride on the ocean near the house. Suddenly, their horse, named Astro, stumbled and landed right in a shaky pit full of viscous mud.

The 18-year-old mare quickly bogged down so that she could not even move, let alone get out on her own. Every time she tried to twitch, Astro only sank deeper into the slush.

Nicole called the rescuers, but for a long time they could not figure out exactly how to pull the horse out. They tried to use fire hoses to pull her through the winch, but the attempt failed. Meanwhile, time was running out, and the water was coming closer and closer. As can be seen from the photographs, the owner of Astro was madly worried and realized with horror that if her horse was not pulled out soon, then she would simply drown in the oncoming tide.

Under the scorching Australian heat, Astro spent more than 3 hours before she was finally pulled out using a tractor borrowed from a local farmer. The horse was very emaciated, and she was immediately sent to the veterinarian.

Don't fall into the swamp!

It would seem to everyone an understandable and ordinary question - why does the swamp suck? In fact, this process is not as simple as it seems, and perhaps you will learn something new for yourself.

Firstly, a swamp that sucks in is called a swamp. It can only pull in living objects. The bog is formed on the basis of lakes by overgrowing with a green carpet of moss and algae, not in all swamps.

Two reasons contribute to the emergence of a swamp: overgrowing of a reservoir or swamping of land. The swamp is characterized by excessive moisture, constant deposition of not completely decomposed organic matter - peat. Not all swamps are able to suck in objects, but only those in which a bog has formed. A swamp swamp is formed on the site of a lake. Lilies, water lilies and reeds on the surface of the lake grow over time into a dense carpet on the surface of the reservoir. At the same time, algae grow at the bottom of the lake. As the cloud of algae and moss forms, it rises from the bottom to the surface. Due to the lack of oxygen, rotting begins, organic waste is formed, dispersing in the water and forming a bog.

Now let's move on to the suction process itself ...

The bog sucks in living objects. This is explained by its physical properties. The bog belongs to the class of Bingham liquids, physically described by the Bingham-Shvedov equation. When they hit the surface of an object with a small weight, they behave like solid bodies, so the object will not sink. When an object has a large enough weight, it sinks.

Why are only living objects subject to reloading? This is because such objects are constantly moving. What if it freezes? Will the dive stop? Alas, this will only slow down the immersion, because a living body always moves because it breathes. Inanimate objects remain motionless, so they do not completely sink. Overloading into a quagmire is the suction of a swamp. Why does the movement of the body accelerate the immersion? Any movement is the application of a force that increases the force of pressure on the support. It is due to the weight of the object and the force of gravity. Sudden movements are the reason for the formation of areas of low pressure under the body. These areas will lead to an increase in atmospheric pressure on a living object, which will further submerge it.

Therefore, the physical definition of the word “sucking in the swamp” looks like this: the Bingham liquid (quagmire) tries to transfer the living object that has fallen into it to a level below normal immersion, in which the Archimedes force is less than the body. The suction process is irreversible. A drowned body, even after the cessation of life, will not emerge.

In addition to theoretical interest, the study physical processes taking place in the swamp is of practical importance: many people die in the swamps who could have survived if they were better aware of the insidious properties of the bog. And these properties are really very insidious. The swamp is like a predator. It reacts differently to living and non-living objects that enter it: it does not touch the dead, but sucks in all living things. This quagmire property deserves special attention and will be of primary interest to us. First, let's describe it in more detail.

In the first approximation, the quagmire can be considered a liquid. Therefore, the Archimedean buoyant force must act on the bodies that have fallen into it. This is true, and objects of even high density, exceeding the density of the human body, do not sink in a quagmire. But as soon as a person or other living being gets into it, they will be “sucked in”, i.e. they will be completely immersed in the quagmire, although their density is less than the density of objects that do not sink in the quagmire.

The question is why the quagmire behaves in such an unexpected way? How does it distinguish living objects from non-living ones?

To answer these questions, we need to take a closer look at physical properties bogs.

On the floating of bodies in Newtonian fluids

Consider how a body floats in Newtonian fluids, such as water. Let us bring a body whose density is less than its density to the surface of the water and let it go. After some time, a state of equilibrium will be established: the body will be immersed to a level at which the Archimedean buoyant force is exactly equal to the weight of the body. This state of equilibrium is stable - if the body is affected external force and drown it deeper (or vice versa, lift it up), then after the termination of the force, it will return to its previous position. The level of immersion at which the Archimedean force is equal to weight, we will call the level of normal immersion.

Please note that the level of normal immersion is determined only by the ratio of densities and does not depend on the viscosity of the liquid. If the swamp were just a Newtonian fluid with a high viscosity, it wouldn't be very dangerous. With reasonable behavior on its surface, one could hold on for quite a long time. Remember how tired swimmers behave if they want to relax right in the water? They roll over on their backs, spread their arms and lie still for as long as they want. Since the density of water is less than the density of the bog, then in a similar way it would be possible to lie on the surface of the bog for a long time, and the viscosity would not particularly interfere with this. It would be possible to slowly think over the situation, make the best decision, try to carefully row with your hands, trying to get to a solid place (here the viscosity would be a hindrance), finally, just wait for help. The buoyant force would securely hold a person on the surface of the swamp: if, as a result of careless movement, a person would sink below the level of normal immersion, the Archimedean force would still push him back.

Unfortunately, the reality is much worse. A person who has fallen into a quagmire has no time to think, much less to wait. The bog is a non-Newtonian fluid and its Bingham properties change the situation drastically.

On the floating of bodies in Bingham fluids

We bring the body to the surface of the Bingham liquid and lower it. If the body is sufficiently light and the pressure exerted by it is small, then it may happen that the stresses arising in the liquid will be less than the yield threshold and the liquid will behave as solid. That is, an object can stand on the surface of the liquid and not sink.

On the one hand, it seems to be good. It is thanks to this property that all-terrain vehicles with low pressure on the ground easily overcome swamps that are impassable for humans. Yes, and a person, with the help of special “bog skis” or wet shoes, can reduce pressure on the soil and feel relatively safe in the swamp. But this phenomenon has another side. The very fact that the immersion of the body stops in the presence of an inequality of weight and Archimedean force is alarming - everything does not happen as usual. Imagine that the weight of our body is large enough and it starts to sink. How long will this dive take place? It is clear that it is not up to those when the Archimedean force becomes equal to the weight. When the body is immersed, the Archimedean force will partially compensate for the weight, the pressure on the soil will decrease, and a moment will come when the stresses again become less to. In this case, the Bingham liquid will stop flowing and the body will stop before, than the Archimedean force becomes equal to the weight. Such a state, when the Archimedean force is less than the weight, but the body does not sink further, is called the state of under-immersion (see Fig. a).

A. now - the most important thing. If states of under-immersion are possible in a liquid, then for the same reasons, states of over-immersion are also possible, in which the Archimedean force is greater than weight, but the body does not float (Fig. c). Remember what happened in the Newtonian fluid? If, as a result of any actions, a person fell below the level of normal immersion, then the Archimedean force became greater than the weight and returned it back. In a Bingham fluid, nothing similar (for a sufficiently large m0) occurs. Having plunged as a result of any careless action, you will no longer emerge back, but will be in an overloaded state. The process of "drowning" in the quagmire is irreversible. Now you can give a more precise meaning to the word "sucking". It means the tendency of the quagmire to sink living objects below the level of normal immersion - into an overloaded state.

There is very little left for us - to figure out why the swamp bog sucks in, i.e., carries only living objects into an overloaded state.

Reasons for overload

Living objects are overloaded because, once in a quagmire, they move, i.e. change mutual arrangement parts of your body. This leads to overload for four reasons.

Reason one. Imagine that you have a heavy load in your hands and you begin to lift it. To give it an upward acceleration, you must act on it with a force that exceeds the weight of this body. In accordance with Newton's third law, the force acting on your hands from the side of the load will also be greater than its weight. Therefore, the force with which your legs press on the support will increase. If you are standing in a bog, then trying to lift the load you are holding will cause your feet to sink deeper into the bog.

And if there is no cargo in hand? This does not change the fundamental side of the matter - the hand has mass, and therefore is itself a load. If you are at the level of normal immersion, then simply raising your arm will result in overload. AT this case the overload will be very small, but it will be irreversible, and repeated movements can lead to a large amount of overload.

The second reason. The bog has a high stickiness and in order to tear, for example, a hand from the surface of the bog, you need to apply force. In this case, the pressure on the support increases and overload will occur.

Reason three. The bog is a viscous medium and resists objects moving in it. If you try to pull out a stuck hand, then when it moves, you will have to overcome the forces of viscosity, and the pressure on the support increases. Overload will happen again.

Reason four. Everyone is well aware that when pulling a foot out of the mud, a characteristic squelching sound is heard - this atmospheric air fills the footprint left by the foot. Why do you think such a sound is not heard when pulling a leg out of the water? The answer is quite obvious - water has a low viscosity, flows quickly and has time to fill the space under the leg moving up. Mud has a much greater viscosity and the forces that prevent the movement of some layers relative to others are greater for it. Therefore, the dirt flows slowly and does not have time to fill the space under the foot. A "void" is formed there - an area of low pressure, not occupied by soil. When you pull your foot out of the mud, this area communicates with the atmosphere, air rushes into it, and as a result, the very sound that we talked about earlier is heard.

Thus, the presence of a squelching sound indicates that when trying to free a foot stuck in mud, one has to overcome not only the forces due to stickiness and viscosity, but also the forces associated with atmospheric pressure.

With sudden movements of a person who has fallen into a quagmire, areas of low pressure will appear under the parts of the body moving in the quagmire, and atmospheric pressure will press down on the person with great force, pushing him into an overloaded state.

The combined action of all four causes leads to the following effect: a change in the shape of a body that has fallen into a quagmire leads to its overload.

Now much has become clear. Inanimate bodies do not change their shape when they fall into the quagmire, and there are no reasons for their reloading. Such bodies are not sucked in by the bog, they, having fallen into the quagmire, will remain in a state of undersubmergence. And living beings, having fallen into a quagmire, begin to fight for their lives, flounder, which immediately leads to their overload. This is "sucking". The answer to the question posed at the very beginning has been received. However, this is not enough. How, after all, to be saved, how to use the results of this review to develop practical recommendations for those who have fallen into the quagmire.

Alas, much less can be done in this direction than we would like. If we do not consider fantastic and semi-fatalistic projects (“instantly inflated balloon pulling a person out of a quagmire”, “a substance that hardens a swamp”), etc.), then the situation looks bleak.

How can you get out of the quagmire?

The main rule that everyone needs to know is not to make any sudden movements when you are in a swamp. If it sucks slowly into the swamp, there is every chance to escape. Firstly, once in a swampy area, you need to get a stick, it is desirable that it be wide and strong, that is, a real bar. This stick can be your salvation, so you need to choose it carefully, and not take the first knot that comes to hand. If you find yourself in a swamp, slipping off a bump, then you will most likely be sucked in quickly, because by inertia you will continue to move, thereby helping the bog, so it’s better to fall on your stomach or back, so you will be sucked in much more slowly.

If you have absolutely nothing at hand that could serve as a lever for you, try to take a horizontal position. Do this as carefully as possible, carefully shifting your center of gravity from your legs to your torso, if you manage to do this, then your body weight will decrease significantly and you will no longer be dragged into the swamp. In this position, you can wait for help. But, being in a swamp, in no case should you make sudden movements, wave your arms and try to pull your legs, this will suck you in the abyss even more.

Those in this position should not even shout loudly, calling for help, and even more so swing their free limbs. If the top of your body is still free, then you need to take off your jacket or raincoat and throw it on the surface of the swamp, you can also get out on it, it will not allow the swamp to suck you in.

If it sucks into the swamp very quickly, then only an outsider can help, he must throw a rope or a stick, along which a person who has fallen into a swamp could get out onto a hard surface. Sometimes it takes at least three people on land, since the suction force of the swamp is very high. It should also be remembered that if a person is pulled out of a swamp, then in no case should he be released in order to take a break, a slightly released person will instantly go into the quagmire, having received additional energy from the land during repulsion. The rescue operation must be active and without delay. Then success will be guaranteed.

What else can the swamps tell us?

There is such a phenomenon as peat tanning - a peculiar state of a corpse that occurs when a corpse enters peat bogs and soils containing humic acids. Peat "tanning" can also be called one of the types of natural preservation of a dead body. The corpse, which is in a state of peat "tanning", has a dense dark brown, as if tanned skin. Internal organs decrease in volume. Under the action of humic acids, mineral salts in the bones dissolve and are completely washed out of the corpse. Bones in this state resemble cartilage in consistency. Corpses in peat bogs are well preserved indefinitely, and by examining them, forensic doctors can determine the injuries sustained during life. Although such cases are quite rare, sometimes finds in peat bogs can present various surprises to researchers.

There are terrible swamps on our planet, famous for their terrible, but historically priceless finds. It's about about the "swamps of human organs" in Germany, Denmark, Ireland, Great Britain and the Netherlands.

Perhaps the most famous of the swamp mummies is the Tollund Man, who was stumbled upon by two peat-gathering brothers near the village of Tollund in May 1950.

They were cutting peat into briquettes when they suddenly saw a face looking straight at them and, thinking that this was the victim of a recent murder, they immediately contacted the local police.

Radiocarbon dating of Tollund Man's hair soon after showed that he died around 350 BC. e.

Another ancient Dane with perfectly preserved hair was found in 1952 in a swamp near the town of Groboll. Judging by the cut throat, the poor fellow was killed and the corpse was thrown into the swamp.

Well, the severed skull of the so-called man from Osterby, found in a swamp near the German village of the same name, gives an idea of what hairstyles older men wore in ancient Germanic tribes who lived on the territory of Germany in the first millennium BC. This hairstyle is called the Swabian knot. The hair of the deceased was originally gray, and became red due to oxidation in a gloomy peat deep.

Acidic water, low temperature, lack of oxygen - everything the necessary conditions to save. The internal organs, hairline, skin are so well preserved that they can be used to find out exactly what hairstyle a person wore, what he ate before his death, and even what he was wearing 2000-2500 years ago.

On the this moment about 2000 swamp people are known. Of these, the most famous are the man from Tollund, the woman from Elling, the Girl from Ide, Bogbody from Windeby, and the man from Lindow.

The age of most marsh people according to the results of radiocarbon analysis is 2000-2500 years, but there are also much older finds.

So, a woman from Kölbjerg died about 10,000 years ago in the era of the Maglemose archaeological culture.

On some bodies, clothes or fragments of them were preserved, which made it possible to supplement the data on the historical costume of those years. The best-preserved objects are: a pointed leather cap of a man from Tollund; a woolen dress found near the burial site of a woman from Hüldremose; woolen windings from legs separated from the body from a swamp in Denmark.

In addition, thanks to the finds on whose heads the hair was preserved, it was possible to reconstruct the hairstyles of the ancients. Thus, a man from Clonycavan styled his hair with a mixture of resin and vegetable oil, and the hair on the skull of a man from Osterby was laid over the right temple and tied with the so-called "Swabian knot", which confirmed the hairstyles of the Suebi described by Tacitus.

Bog body from Windeby (German: Moorleiche von Windeby) - this is the name given to the well-preserved body of a teenager found in a peat bog in northern Germany.

The body was found in 1952 by peat workers near the village of Vindeby in Schleswig-Holstein. Scientists were informed about the discovery, who removed the corpse from the quagmire and began research.

With the help of spore-pollen analysis, it was found that the teenager died in the Iron Age at the age of 14. In 2002, using radiocarbon analysis, the time of his death was more accurately dated - between 41 and 118 AD. e. Radiographs showed the presence of defects in the bones of the lower leg (Harris lines), which indicates malnutrition and, as a result, impaired growth. Accordingly, death could come from starvation.

I have heard many horror stories of people drowning in swamps. I have always been interested in the mechanism of How does this happen. The other day we were visiting the village with my husband's parents. His dad works as a forester, so he told me everything he knows about swamps and how they work. suction mechanism.

How a swamp is formed

Swamp, like any other natural object, arises or by itself or with human hands. Of course not, intentionally people do not create swamps, but, for example, due to poor care of natural reservoirs, due to deforestation, due to land pollution, the swamp world develops and grows.

I'll start with what not all swamps can suck foreign objects, but only those that are called "quagmire". That is, these swamps are overgrown bogs. So, How is a swamp formed?

The lake begins to be covered with a dense carpet of lilies and moss.
The humidity of the pond is rising due to the constant deposition of peat.
Algae grows on the bottom, which eventually reach almost to the surface of the water.
Due to the lack of a, over time, and the complete absence of oxygen, rotting begins in the water.
As a result of decay a quagmire is formed.

Why does the swamp suck

I don’t know about you, but I (until my father-in-law told me) didn’t know that the quagmire sucks only living objects. This happens due to physical lawBingama-Shvedova. By the way, there are two types of suction: underload and overload. Underdive happens if the weight submersible bodies smaller than pushing out swamp power. If a the weight of the submerged body is greater - going on overload.

As for drowning people and animals, then, in 95% of the case, overload occurs, since the weight of living bodies is usually quite large. By the way, the more moving body while the swamp tries to suck him in, the faster overload will occur. Unfortunately, neither man nor beast you can't get out of the swamp alone(only in exceptionally good cases), because even if you try to stop moving, breath doesn't matter can't hold up for long(and this is also a movement). Immersion in this case will be slower but completely will not stop.

It would seem that everyone understands the question - why does the swamp suck? In fact, this process is not as simple as it seems, and perhaps you will learn something new for yourself.

Firstly, a swamp that sucks in is called a swamp. It can only pull in living objects. The bog is formed on the basis of lakes by overgrowing with a green carpet of moss and algae, not in all swamps.

Now let's move on to the suction process itself ...

Why are only living objects subject to reloading? This is because such objects are constantly moving. What if it freezes? Will the dive stop? Alas, this will only slow down the immersion, because a living body always moves because it breathes. Inanimate objects remain motionless, so they do not completely sink. Overloading into a quagmire is the suction of a swamp. Why does the movement of the body accelerate the immersion? Any movement is the application of a force that increases the force of pressure on the support. It is due to the weight of the object and the force of gravity. Sharp movements are the reason for the formation of areas of low pressure under the body. These areas will lead to an increase in atmospheric pressure on a living object, which will further submerge it.

In addition to theoretical interest, the study of the physical processes occurring in the swamp is of practical importance: many people die in the swamps, who could have survived if they were better aware of the insidious properties of the bog. And these properties are really very insidious. The swamp is like a predator. It reacts differently to living and non-living objects that enter it: it does not touch the dead, but sucks in all living things. This property of the bog deserves special attention and will interest us in the first place. First, let's describe it in more detail.

The question is why the quagmire behaves in such an unexpected way? How does it distinguish living objects from non-living ones?

To answer these questions, we will have to dwell in more detail on the study of the physical properties of the bog.

On the floating of bodies in Newtonian fluids

Consider how a body floats in Newtonian fluids, such as water. Let us bring a body whose density is less than its density to the surface of the water and let it go. After some time, a state of equilibrium will be established: the body will be immersed to a level at which the Archimedean buoyant force is exactly equal to the weight of the body. This state of equilibrium is stable - if an external force acts on the body and sinks it deeper (or vice versa, lift it up), then after the force stops, it will return to its previous position. The level of immersion at which the Archimedean force is equal to the weight, we will call the level of normal immersion.

Please note that the level of normal immersion is determined only by the ratio of densities and does not depend on the viscosity of the liquid. If the swamp were just a Newtonian fluid with a high viscosity, it wouldn't be very dangerous. With reasonable behavior on its surface, one could hold on for quite a long time. Remember how tired swimmers behave if they want to relax right in the water? They roll over on their backs, spread their arms and lie still for as long as they want. Since the density of water is less than the density of the bog, then in a similar way it would be possible to lie on the surface of the bog for a long time, and the viscosity would not particularly interfere with this. It would be possible to take your time to think about the situation, make the best decision, try to carefully row with your hands, trying to get to a solid place (viscosity would be a hindrance here), finally, just wait for help. The buoyancy force would hold the person securely on the surface of the swamp: if, as a result of careless movement, the person would sink below the level of normal immersion, the Archimedean force would still push him back.

On the floating of bodies in Bingham fluids

We bring the body to the surface of the Bingham liquid and lower it. If the body is sufficiently light and the pressure exerted by it is small, then it may happen that the stresses arising in the liquid will be less than the yield threshold and the liquid will behave like a solid body. That is, an object can stand on the surface of the liquid and not sink.

On the one hand, it seems to be good. It is thanks to this property that all-terrain vehicles with low pressure on the ground easily overcome swamps that are impassable for humans. Yes, and a person, with the help of special “bog skis” or wet shoes, can reduce pressure on the soil and feel relatively safe in the swamp. But this phenomenon has another side. The very fact that the immersion of the body stops in the presence of an inequality of weight and Archimedean force is alarming - everything does not happen as usual. Imagine that the weight of our body is large enough and it starts to sink. How long will this dive take place? It is clear that it is not up to those when the Archimedean force becomes equal to the weight. When the body is immersed, the Archimedean force will partially compensate for the weight, the pressure on the soil will decrease, and a moment will come when the stresses again become less to. In this case, the Bingham fluid will stop flowing and the body will stop before the Archimedean force becomes equal to the weight. Such a state, when the Archimedean force is less than the weight, but the body does not sink further, is called the state of under-immersion (see Fig. a).

And now - the most important thing. If states of under-immersion are possible in a liquid, then for the same reasons, states of over-immersion are also possible, in which the Archimedean force is greater than the weight, but the body does not float (Fig. c). Remember what happened in the Newtonian fluid? If, as a result of any actions, a person fell below the level of normal immersion, then the Archimedean force became greater than the weight and returned it back. In a Bingham fluid, nothing analogous (for sufficiently large m0) occurs. Having plunged as a result of any careless action, you will no longer emerge back, but will be in an overloaded state. The process of "drowning" in the quagmire is irreversible. Now you can give a more precise meaning to the word "sucking". It means the tendency of the quagmire to drown living objects below the level of normal immersion - into an overloaded state.

It remains for us quite a bit - to figure out why the swamp bog sucks in, i.e., only living objects are carried into an overloaded state.

Reasons for overload

Living objects are overloaded because, once in a quagmire, they move, that is, they change the relative position of their body parts. This leads to overload for four reasons.

Reason one. Imagine that you have a heavy load in your hands and you begin to lift it. To give it an upward acceleration, you must act on it with a force that exceeds the weight of this body. In accordance with Newton's third law, the force acting on your hands from the side of the load will also be greater than its weight. Therefore, the force with which your legs press on the support will increase. If you are standing in a bog, then trying to lift the load you are holding will cause your feet to sink deeper into the bog.

And if there is no cargo in hand? This does not change the fundamental side of the matter - the hand has mass, and therefore it is itself a load. If you are at the level of normal immersion, then simply raising your arm will result in overload. In this case, the overload will be very small, but it will be irreversible, and repeated movements can lead to a large overload.

The second reason. The bog has a high stickiness and in order to tear, for example, a hand from the surface of the bog, you need to apply force. In this case, the pressure on the support increases and overload will occur.

Reason three. The bog is a viscous medium and resists objects moving in it. If you try to pull out a stuck hand, then when it moves, you will have to overcome the forces of viscosity, and the pressure on the support increases. There will be an overload again.

Reason four. Everyone is well aware that when pulling a foot out of the mud, a characteristic squelching sound is heard - this is atmospheric air filling the footprint left by the foot. Why do you think such a sound is not heard when pulling a leg out of the water? The answer is quite obvious - water has a low viscosity, flows quickly and has time to fill the space under the leg moving up. Mud has a much greater viscosity and the forces that prevent the movement of some layers relative to others are greater for it. Therefore, the dirt flows slowly and does not have time to fill the space under the foot. A "void" is formed there - an area of low pressure, not occupied by soil. When you pull your foot out of the mud, this area communicates with the atmosphere, air rushes into it, and as a result, the very sound that we talked about earlier is heard.

The combined action of all four causes leads to the following effect: a change in the shape of a body that has fallen into a quagmire leads to its overload.

Alas, much less can be done in this direction than we would like. If we do not consider fantastic and semi-fatastic projects ("an instantly inflating balloon that pulls a person out of a quagmire", "a substance that causes a hardening of a swamp", etc.), then the situation looks bleak.

How can you get out of the quagmire?

If it sucks into the swamp very quickly, then only an outsider can help, he must throw a rope or a stick, along which a person who has fallen into a swamp could get out onto a hard surface. Sometimes, in order to pull one person out of the swamp, at least three people are required on land, since the suction force of the swamp is very high. It should also be remembered that if a person is pulled out of a swamp, then in no case should he be released in order to take a break, a slightly released person will instantly go into the quagmire, having received additional energy from the land during repulsion. The rescue operation must be active and without delay. Then success will be guaranteed.

What else can the swamps tell us?

There is such a phenomenon as peat tanning - a peculiar state of a corpse that occurs when a corpse enters peat bogs and soils containing humic acids. Peat "tanning" can also be called one of the types of natural preservation of a dead body. The corpse, which is in a state of peat "tanning", has a dense dark brown, as if tanned skin. Internal organs are reduced in volume. Under the action of humic acids, mineral salts in the bones dissolve and are completely washed out of the corpse. Bones in this state resemble cartilage in consistency. Corpses in peat bogs are well preserved indefinitely, and when examining them, forensic doctors can determine the injuries sustained during life. Although such cases are quite rare, sometimes finds in peat bogs can present various surprises to researchers.

There are terrible swamps on our planet, famous for their terrible, but historically priceless finds. We are talking about the "swamps of human organs" in Germany, Denmark, Ireland, Great Britain and the Netherlands.

Perhaps the most famous of the swamp mummies is the Tollund Man, who was stumbled upon by two peat-gathering brothers near the village of Tollund in May 1950.

They were cutting peat into briquettes when they suddenly saw a face looking straight at them and, thinking that this was the victim of a recent murder, they immediately contacted the local police.

Radiocarbon dating of Tollund Man's hair soon after showed that he died around 350 BC. e.

Well, the severed skull of the so-called man from Osterby, found in a swamp near the German village of the same name, gives an idea of what hairstyles were worn by elderly men in the ancient Germanic tribes who lived on the territory of Germany in the first millennium BC. This hairstyle is called the Swabian knot. The hair of the deceased was originally gray, and became red due to oxidation in a gloomy peat deep.

Acidic water, low temperature, lack of oxygen are all necessary conditions for preservation. The internal organs, hairline, skin are so perfectly preserved that you can accurately find out from them what hairstyle a person wore, what he ate before his death, and even what he was wearing 2000-2500 years ago.

At the moment, about 2000 swamp people are known. Of these, the most famous are the man from Tollund, the woman from Elling, the Girl from Ide, Bogbody from Windeby, and the man from Lindow.

The age of most marsh people according to the results of radiocarbon analysis is 2000-2500 years, but there are also much older finds.

So, a woman from Kölbjerg died about 10,000 years ago in the era of the Maglemose archaeological culture.

Bog body from Windeby (German: Moorleiche von Windeby) - this is the name given to the well-preserved body of a teenager found in a peat bog in northern Germany.

It would seem to everyone an understandable and ordinary question - why does the swamp suck? In fact, this process is not as simple as it seems, and perhaps you will learn something new for yourself.

Firstly, a swamp that sucks in is called a swamp. It can only pull in living objects. The bog is formed on the basis of lakes by overgrowing with a green carpet of moss and algae, not in all swamps.

Now let's move on to the suction process itself ...

Why are only living objects subject to reloading? This is because such objects are constantly moving. What if it freezes? Will the dive stop? Alas, this will only slow down the immersion, because a living body always moves because it breathes. Inanimate objects remain motionless, so they do not completely sink. Overloading into a quagmire is the suction of a swamp. Why does the movement of the body accelerate the immersion? Any movement is the application of a force that increases the force of pressure on the support. It is due to the weight of the object and the force of gravity. Sharp movements are the reason for the formation of areas of low pressure under the body. These areas will lead to an increase in atmospheric pressure on a living object, which will further submerge it.

The question is why the quagmire behaves in such an unexpected way? How does it distinguish living objects from non-living ones?

To answer these questions, we will have to dwell in more detail on the study of the physical properties of the bog.

On the floating of bodies in Newtonian fluids

Consider how a body floats in Newtonian fluids, such as water. Let us bring a body whose density is less than its density to the surface of the water and let it go. After some time, a state of equilibrium will be established: the body will be immersed to a level at which the Archimedean buoyant force is exactly equal to the weight of the body. This state of equilibrium is stable - if an external force acts on the body and sinks it deeper (or vice versa, lift it up), then after the force stops, it will return to its previous position. The level of immersion at which the Archimedean force is equal to the weight, we will call the level of normal immersion.

Please note that the level of normal immersion is determined only by the ratio of densities and does not depend on the viscosity of the liquid. If the swamp were just a Newtonian fluid with a high viscosity, it wouldn't be very dangerous. With reasonable behavior on its surface, one could hold on for quite a long time. Remember how tired swimmers behave if they want to relax right in the water? They roll over on their backs, spread their arms and lie still for as long as they want. Since the density of water is less than the density of the bog, then in a similar way it would be possible to lie on the surface of the bog for a long time, and the viscosity would not particularly interfere with this. It would be possible to take your time to think about the situation, make the best decision, try to carefully row with your hands, trying to get to a solid place (viscosity would be a hindrance here), finally, just wait for help. The buoyancy force would hold the person securely on the surface of the swamp: if, as a result of careless movement, the person would sink below the level of normal immersion, the Archimedean force would still push him back.

On the floating of bodies in Bingham fluids

We bring the body to the surface of the Bingham liquid and lower it. If the body is sufficiently light and the pressure exerted by it is small, then it may happen that the stresses arising in the liquid will be less than the yield threshold and the liquid will behave like a solid body. That is, an object can stand on the surface of the liquid and not sink.

On the one hand, it seems to be good. It is thanks to this property that all-terrain vehicles with low pressure on the ground easily overcome swamps that are impassable for humans. Yes, and a person, with the help of special “bog skis” or wet shoes, can reduce pressure on the soil and feel relatively safe in the swamp. But this phenomenon has another side. The very fact that the immersion of the body stops in the presence of an inequality of weight and Archimedean force is alarming - everything does not happen as usual. Imagine that the weight of our body is large enough and it starts to sink. How long will this dive take place? It is clear that it is not up to those when the Archimedean force becomes equal to the weight. When the body is immersed, the Archimedean force will partially compensate for the weight, the pressure on the soil will decrease, and a moment will come when the stresses again become less to. In this case, the Bingham fluid will stop flowing and the body will stop before the Archimedean force becomes equal to the weight. Such a state, when the Archimedean force is less than the weight, but the body does not sink further, is called the state of under-immersion (see Fig. a).

A. now - the most important thing. If states of under-immersion are possible in a liquid, then for the same reasons, states of over-immersion are also possible, in which the Archimedean force is greater than the weight, but the body does not float (Fig. c). Remember what happened in the Newtonian fluid? If, as a result of any actions, a person fell below the level of normal immersion, then the Archimedean force became greater than the weight and returned it back. In a Bingham fluid, nothing analogous (for sufficiently large m0) occurs. Having plunged as a result of any careless action, you will no longer emerge back, but will be in an overloaded state. The process of "drowning" in the quagmire is irreversible. Now you can give a more precise meaning to the word "sucking". It means the tendency of the quagmire to drown living objects below the level of normal immersion - into an overloaded state.

It remains for us quite a bit - to figure out why the swamp bog sucks in, i.e., only living objects are carried into an overloaded state.

Reasons for overload

Living objects are overloaded because, once in a quagmire, they move, that is, they change the relative position of their body parts. This leads to overload for four reasons.

Reason one.
Imagine that you have a heavy load in your hands and you begin to lift it. To give it an upward acceleration, you must act on it with a force that exceeds the weight of this body. In accordance with Newton's third law, the force acting on your hands from the side of the load will also be greater than its weight. Therefore, the force with which your legs press on the support will increase. If you are standing in a bog, then trying to lift the load you are holding will cause your feet to sink deeper into the bog.

The second reason.
The bog has a high stickiness and in order to tear, for example, a hand from the surface of the bog, you need to apply force. In this case, the pressure on the support increases and overload will occur.

Reason three.
The bog is a viscous medium and resists objects moving in it. If you try to pull out a stuck hand, then when it moves, you will have to overcome the forces of viscosity, and the pressure on the support increases. Overload will happen again.

Reason four.
Everyone is well aware that when pulling a foot out of the mud, a characteristic squelching sound is heard - this is atmospheric air filling the footprint left by the foot. Why do you think such a sound is not heard when pulling a leg out of the water? The answer is quite obvious - water has a low viscosity, flows quickly and has time to fill the space under the leg moving up. Mud has a much greater viscosity and the forces that prevent the movement of some layers relative to others are greater for it. Therefore, the dirt flows slowly and does not have time to fill the space under the foot. A "void" is formed there - an area of low pressure, not occupied by soil. When you pull your foot out of the mud, this area communicates with the atmosphere, air rushes into it, and as a result, the very sound that we talked about earlier is heard.

The combined action of all four causes leads to the following effect: a change in the shape of a body that has fallen into a quagmire leads to its overload.

Alas, much less can be done in this direction than we would like. If we do not consider fantastic and semi-fatastic projects (“an instantly inflating balloon that pulls a person out of a quagmire”, “a substance that causes a hardening of a swamp”), then the situation looks bleak.

How can you get out of the quagmire?

If it sucks into the swamp very quickly, then only an outsider can help, he must throw a rope or a stick, along which a person who has fallen into a swamp could get out onto a hard surface. Sometimes, in order to pull one person out of the swamp, at least three people are required on land, since the suction force of the swamp is very high. It should also be remembered that if a person is pulled out of a swamp, then in no case should he be released in order to take a break, a slightly released person will instantly go into the quagmire, having received additional energy from the land during repulsion. The rescue operation must be active and without delay. Then success will be guaranteed.

What else can the swamps tell us?

There is such a phenomenon as peat tanning - a peculiar state of a corpse that occurs when a corpse enters peat bogs and soils containing humic acids. Peat "tanning" can also be called one of the types of natural preservation of a dead body. The corpse, which is in a state of peat "tanning", has a dense dark brown, as if tanned skin. Internal organs are reduced in volume. Under the action of humic acids, mineral salts in the bones dissolve and are completely washed out of the corpse. Bones in this state resemble cartilage in consistency. Corpses in peat bogs are well preserved indefinitely, and when examining them, forensic doctors can determine the injuries sustained during life. Although such cases are quite rare, sometimes finds in peat bogs can present various surprises to researchers.