phrase Walpurgis Night causes fear and awe in the common man. Walpurgis Night is always associated with some kind of devilry and revelry of witches. It is impossible for an ordinary person to understand what is happening around, and whether it is a reality. Since ancient times, our ancestors used Walpurgis Night to expel devils and cleanse the house of evil spirits. This holiday dates back to ancient times and belongs to pagan beliefs. It has an exact date on the calendar, which falls on the first of May. On the night of April 30 to May 1, all the souls of the dead come out to people and arrange the most incredible things.

Pre-religious celebrations of Walpurgis Night.

The name of the Beltane holiday is not known to many in our time, but in the eighth century it was the most desired and long-awaited for the pagans. From many Gaelic dialects, the name of the holiday is translated as May, which means that it is time to drive the cattle to the summer pastures. Many legends and beliefs are associated with the first of May. On this day, the most important pagan deity - the Sun descends from heaven to earth and he needs to make a sacrifice. This is done so that the whole year is fruitful and not devoid of higher patronage.

In November, Samhain was celebrated, which completed the bright half of the year, opened by Beltane. Both of these days were very important for the pagans, because they symbolized the beginning and end of the fertile summer period. At the same time, the traditional actions of the first of November and the first of May coincided. The burning of bonfires, which were lit at the highest places, was considered an obligatory ritual.

Preparation for the holiday was carried out very carefully. A week before the celebration, all the inhabitants were engaged in the collection of special types of wood, which was supposed to burn in the sacred fire. Two huge fires on the mountain were surrounded by a deep moat. It was meant for the audience.

Long before dawn, all the inhabitants left their houses and, chasing animals in front of them, climbed to huge fires. They took their place in the moat and silently waited for the sunrise. The first rays of the sun gave a start to lighting a fire and chanting. Three times all the people passed around the fire, drove herds of animals through it and brought torches into the houses to consecrate and illuminate the family hearth.

Some peoples had a tradition of planting the May bush and decorating it. In Germany, the Maypole was installed, games were played near it and round dances were played. This cheerful celebration was forbidden with the advent of Christianity, as a relic of paganism. It is very difficult to get out of the habitual way of life, so old women, on pain of death, continued to carry out traditional rituals, hiding in dense forests. After some time, the holiday was forgotten, and the spring celebration turned into a witches' sabbath.

History of Walpurgis Night.

Surprisingly, the traditions of celebrating Walpurgis Night are associated with a specific historical person. A native of Devonshire, Walburga was the daughter of a Saxon king named Richard. Going on a long journey to the Holy Land, the father is very worried about the safety of his little girl, so he leaves her in the care of the strict abbess of the Winborn monastery. Within these walls, young Walburga was destined to live for twenty-six years. Then, as part of a group of missionaries, the nun of royal blood went to Germany. On the way, a terrible storm hit the ship, and all the travelers fell into a panic. The nun Walburga knelt down and began to pray, the others followed suit, and the storm vanished as quickly as it had appeared. Since then, sailors began to revere her as their patroness.

Having gone a long way as a nun and abbess, she became famous for her miracles, which she performed with faith in God. The date of her death is the twenty-fifth of February 777. After her burial, repairs were started in the abbey and the grave of the saint was desecrated. The soul of Walburga came to the new abbot, and he ordered the remains of the deceased to be transferred to a cave in Aystadt. It happened on the first of May. Healing moisture began to ooze from the rock, which brought relief to all those who were suffering. After the canonization of Walburga, her remains were taken to the temples of Germany in order to achieve her patronage.

You may wonder what connected this holy woman with the unclean forces that come to light on Walpurgis Night? There are several interesting and at the same time suspicious facts.
The day of her commemoration coincides with the celebration of the pre-Christian celebration dedicated to the arrival of spring.
On the frescoes depicting the saint, there are strange symbols that are not characteristic of the image of a nun. She is depicted against the backdrop of lindens and mountains, as well as with a dog and a mirror. All these symbols speak of her connection with natural or pagan beliefs, rather than with Christian ones. In the image of Walburga, the canons of faith and traditional customs of the pagans were intertwined.

Walpurgis Night in the folklore image.

Walpurgis Night has its reflection in folklore and literary creativity. This event could not go unnoticed and over the centuries has acquired many legends, stories and fables. Their homeland is Germany.
From the Middle Ages, the prejudice stretches to our days that Walpurgis Night- this is a rampage of witches that captures all of Germany. At the same time, villagers burned effigies of witches at the stake and cleared houses and fields from evil spirits. Meanwhile, the witches, on the contrary, prevented the start of the warm season and spent all the time until dawn in terrible dances and bacchanalia.

It was believed that many herbs on Walpurgis Night acquire a special healing power. In this regard, women versed in herbs went out into the forests and fields and collected precious roots. After that, they treated all the suffering with their decoctions with an unshakable faith in success and a positive result.
The inhabitants of the Middle Ages sacredly believed in all the stories about Walpurgis Night and were afraid of evil spirits. All decent people tried to protect themselves and their property.

Traditions of Walpurgis Night.

The gathering place of all witches is Bald Mountain, which is located in Germany. This is where the elite of the witch world meets. They come, fly on brooms and pitchforks, accompanied by devils who are their lovers. Satan himself rules the ball here, who, in the form of a horned goat, sits in the most honorable place in the center. Each witch is obliged to show her respect to the master. They take turns approaching the dais and kissing the ruler. The most beautiful witch, who is the ringleader and is considered the queen of the assembly, enjoys special favor with Satan.

Having shown their reverence to Satan under songs and dances, everyone began to tell what they had done over the past year and what evil they had done. Here it is decided what the witches will do the whole next year, and what meanness they will commit in relation to the human race. Satan is a strict judge, he does not forgive those who disobey him and severely punishes with whiplash.

To start the diabolical meal, the witches light numerous torches. Dishes on the table are peculiar. This is, first of all, horse meat, which is consumed without salt and bread. All drinks are served from the horns, hooves and skulls of animals. Over the mountain, the sounds of a devilish orchestra are heard, consisting of cat tails and horse skulls.

After a plentiful meal and libations, the witches arrange frantic dances near the fire. Their gentlemen - demons do not stop jumping and spinning, as in a frying pan. Here, depraved and lustful orgies are arranged, in which everyone who is on the mountain participates. When Walpurgis Nightends, at the site of the Sabbath, people see bare bones and hoof marks.

Walpurgis Night today.

The traditions of the ancestors have found their response in our days. Many peoples of Central and Northern Europe continue to celebrate the holiday of spring and the flowering of nature. Following ancient traditions, people burn huge bonfires, trying to make them as bright and large as possible. Thus, they disperse the witches who have gathered for the sabbath and purify themselves by the power of fire. All day long, concerts with student performances, round dances and games are held on the squares of the cities. For more than a hundred years, celebrations on Walpurgis Night have been held according to such a program. In different countries, despite the general concept of the holiday, there are some peculiarities of its implementation. Traditions have been unshakable for a long time.

Scandinavians on Walpurgis Night, like other nations, kindle bonfires and perform cleansing rituals. They burn all the garbage that has accumulated over the year. In honor of the holiday, a special dish is prepared - gravlax. It has no analogues in the culinary traditions of other nations. Fresh fish - salmon is pre-aged in salt with the addition of sugar and dill.

In other European countries Walpurgis Night accompanied by explosions of firecrackers and loud noises. It is believed that evil spirits, frightened by the noise, will run away into the forests and will not bother respectable citizens. Firecrackers are trusted to blow up by the boys after sunset.

Walpurgis Night Czechs have a special holiday. In this country, there are many legends about this day, and among people lives in front of evil spirits. So that not a single witch gets into the house and harms people, a lot of sand and grass are poured on the threshold. According to legend, before entering the room, they count everything that lies on the threshold. The more sand there is, the less likely it is that the witch will manage before dawn.

Walpurgis Night for the Bavarians, time of trouble. On a holiday, for fun, doors are removed from their hinges and transferred to another place, while their handles are smeared with paste or soot. And if you gape, then the laces will either be stolen or tied together.

Walpurgis Night has not gone down in history, but remains a valid holiday. The uniqueness of the celebration is that it contains three directions: the holiday of spring, the witches' sabbath and the day of commemoration of the canonized saint.

Strength- a measure of the mechanical interaction of bodies. Force is the cause of a change in the speed of a body or the occurrence of deformations in it (a change in shape or volume). Force is a vector quantity characterized by its modulus (magnitude), direction and point of application of the force. The line of action of the force is a straight line passing through the point of application of the force and continuing the direction of the force vector. The SI unit of force is Newton [N]. All forces in nature are based on four types of fundamental interactions:

• electromagnetic forces acting between electrically charged bodies,
• gravitational forces acting between massive objects,
• strong nuclear force, acting on scales of the order of the size of an atomic nucleus and less (responsible for the connection between quarks in hadrons and for the attraction between nucleons in nuclei).
• weak nuclear interaction, which manifests itself at distances much smaller than the size of the atomic nucleus.

The intensity of the strong and weak interactions is measured in units of energy (electron volts), and not in units of force, and therefore the application of the term "force" to them is arbitrary. The action of a force can take place both in direct contact (friction, pressure on each other in direct contact), and through the fields created by the bodies (gravitational field, electromagnetic field). An interesting and informative site http://mistermigell.ru for you.
From the point of view of the action of forces on the system, consider:

• internal forces - forces of interaction between points (bodies) of a given system;
• external forces - forces acting on points (bodies) of a given system from points (bodies) that do not belong to this system. External forces are called loads.

Forces can be divided into:

• reactive forces − coupling reactions. If the movement of a body in space is limited by other bodies (bonds, supports), the forces with which these bodies act on a given body are called connection (support) reactions.
• active forces - forces that characterize the action of other bodies on a given one and change its kinematic state. Active forces, depending on the type of contact, are divided into
• volumetric - forces acting on each particle of the body, for example, the weight of the body;
• surface - forces acting on a part of the body and characterizing the direct contact of the bodies. Surface forces are:
• concentrated - acting on sites that are small compared to the body, for example, the pressure of a wheel on the road;
• distributed - acting on sites that are not small compared to the body, for example, the pressure of a tractor caterpillar on the road.

The most famous forces:
elastic forces- the forces arising from the deformation of the body and opposing this deformation, is of an electromagnetic nature, being a manifestation of intermolecular interaction. The elastic force vector is directed opposite to the displacement, perpendicular to the surface. For example, if you compress an elastic band, after removing the load, it will restore its shape under the action of an elastic force.
Friction forces- the force arising from the relative motion of solids and opposing this motion are of an electromagnetic nature, being a macroscopic manifestation of intermolecular interaction. The friction force vector is directed opposite to the velocity vector. For example, the force of friction occurs when a sled slides on snow, between the soles of the feet and the ground.
Environmental resistance forces- the forces arising from the motion of a solid body in a liquid or gaseous medium are of an electromagnetic nature, being a manifestation of intermolecular interaction. The resistance force vector is directed opposite to the velocity vector. For example, when an aircraft is moving in the air.
Surface tension forces− the forces arising on the surface of the phase separation are electromagnetic in nature, being a manifestation of intermolecular interaction. The tension force is directed tangentially to the interface. For example, a coin can lie on the surface of a liquid, insects run on water.
The force of gravity- the force with which any bodies of the Universe attract each other, it is directly proportional to the product of the masses of these bodies and inversely proportional to the square of the distance between them. For example, the Earth is attracted to the Sun, and, at the same time, the Earth is attracted to the Moon and the Sun.
Gravity is the force acting on the body from the side of the Earth, which imparts to it the acceleration of free fall. Gravity is the sum of the forces of gravitational attraction and the centrifugal force of the Earth's rotation. For example, under the influence of gravity of a body, the Earth falls.
inertia force− fictitious force (not a measure of mechanical interaction) introduced when considering relative motion in non-inertial frames of reference (moving with acceleration) in order to fulfill Newton's second law in them. In the frame of reference associated with a uniformly accelerated body, the force of inertia is directed opposite to the acceleration. From the total force of inertia, for convenience, the centrifugal force directed from the axis of rotation of the body, and the Coriolis force that arises when the body moves relative to the rotating frame of reference can be distinguished for convenience.
There are other forces as well.

Denis, 6th grade, HFML % 27

FUNDAMENTAL FORCES

FUNDAMENTAL FORCES, the four fundamental forces that are known to modern physics. The most famous and weakest is GRAVITY. The force of gravity between the Earth and an object explains the concept of the WEIGHT of an object. Much stronger is the ELECTROMAGNETIC FORCE acting between electrically charged particles. Thanks to it, atoms are attracted to each other, and chemically bonding them to each other. Two other known forces operate only at the subatomic level: WEAK NUCLEAR INTERACTION, associated with the decay of particles, intermediate in level between the gravitational and electromagnetic forces; The STRONG NUCLEAR FORCE, which is associated with the "glue" that binds nuclei together, is the most powerful force known in nature.

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DRIVING FORCES, see FUNDAMENTAL FORCES... Scientific and technical encyclopedic dictionary

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Classical mechanics Newton's second law History ... Fundamental concepts ... Wikipedia

In physics, conservative forces (potential forces) are forces whose work does not depend on the shape of the trajectory (depends only on the initial and final points of application of forces). This implies the definition: conservative forces are forces whose work is according to ... ... Wikipedia

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Type of armed forces, the main component of the sea power of the state, characterizing its ability to control ocean (maritime) communications. Modern navies include not only ships, aircraft and missiles, but also coastal services, ... ... Collier Encyclopedia

Modern Encyclopedia

nuclear forces- NUCLEAR FORCES, forces that hold nucleons (protons and neutrons) in the nucleus. Nuclear forces act only at distances of no more than 10 13 cm, exceed the force of interaction of electric charges by 100 1000 times and do not depend on the charge of nucleons. Nuclear forces... Illustrated Encyclopedic Dictionary

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>>Physics: Forces in nature. Gravitational forces

Let us first find out whether there are many kinds of forces in nature.
At first glance, it seems that we have taken on an overwhelming and insoluble task: there are an infinite number of bodies on Earth and outside it. They interact differently. So, for example, a stone falls to the Earth; an electric locomotive pulls a train; the football player's foot hits the ball; an ebonite stick worn on fur attracts light pieces of paper, a magnet attracts iron filings; a conductor with current turns the compass needle; the Moon and the Earth interact, and together they interact with the Sun; stars and star systems interact, and so on. There is no end to such examples. It seems that in nature there are an infinite number of interactions (forces)? It turns out not!
Four types of forces. In the boundless expanses of the Universe, on our planet, in any substance, in living organisms, in atoms, in atomic nuclei and in the world of elementary particles, we meet with the manifestation of only four types of forces: gravitational, electromagnetic, strong (nuclear) and weak.
Gravitational forces, or the forces of universal gravitation, act between all bodies - all bodies are attracted to each other. But this attraction is usually essential only when at least one of the interacting bodies is as large as the Earth or the Moon. Otherwise, these forces are so small that they can be neglected.
Electromagnetic forces act between particles that have electric charges. The scope of their activities is especially extensive and varied. In atoms, molecules, solid, liquid and gaseous bodies, living organisms, electromagnetic forces are the main ones. Their role in atoms is great.
Scope nuclear forces very limited. They are noticeable only inside atomic nuclei (ie, at distances of the order of 10 -13 cm). Already at distances between particles of the order of 10 -11 cm (a thousand times smaller than the size of an atom - 10 -8 cm), they do not appear at all.
Weak interactions manifest themselves at even shorter distances, on the order of 10 -15 cm. They cause mutual transformations of elementary particles, determine the radioactive decay of nuclei, and thermonuclear fusion reactions.
Nuclear forces are the most powerful in nature. If the intensity of nuclear forces is taken as unity, then the intensity of electromagnetic forces will be 10 -2 , gravitational - 10 -40 , weak interactions - 10 -16 .
Strong (nuclear) and weak interactions manifest themselves at such small distances when the laws of Newtonian mechanics, and together with them the concept of mechanical force, lose their meaning.
In mechanics, we will consider only gravitational and electromagnetic interactions.
Forces in mechanics. In mechanics, they usually deal with three types of forces - gravitational forces, elastic forces and friction forces.
The forces of elasticity and friction are of an electromagnetic nature. We will not explain here the origin of these forces, with the help of experiments it will be possible to find out the conditions under which these forces arise, and to express them quantitatively.
There are four types of interaction in nature. In mechanics, gravitational forces and two types of electromagnetic forces are studied - elastic forces and friction forces.

G.Ya.Myakishev, B.B.Bukhovtsev, N.N.Sotsky, Physics Grade 10

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It is necessary to know the point of application and the direction of each force. It is important to be able to determine exactly what forces act on the body and in what direction. Force is denoted as , measured in Newtons. In order to distinguish between forces, they are designated as follows

Below are the main forces acting in nature. It is impossible to invent non-existent forces when solving problems!

There are many forces in nature. Here we consider the forces that are considered in the school physics course when studying dynamics. Other forces are also mentioned, which will be discussed in other sections.

Gravity

Every body on the planet is affected by the Earth's gravity. The force with which the Earth attracts each body is determined by the formula

The point of application is at the center of gravity of the body. Gravity always pointing vertically down.

Friction force

Let's get acquainted with the force of friction. This force arises when bodies move and two surfaces come into contact. The force arises as a result of the fact that the surfaces, when viewed under a microscope, are not smooth as they seem. The friction force is determined by the formula:

A force is applied at the point of contact between two surfaces. Directed in the direction opposite to the movement.

Support reaction force

Imagine a very heavy object lying on a table. The table bends under the weight of the object. But according to Newton's third law, the table acts on the object with exactly the same force as the object on the table. The force is directed opposite to the force with which the object presses on the table. That is up. This force is called the support reaction. The name of the force "speaks" react support. This force arises whenever there is an impact on the support. The nature of its occurrence at the molecular level. The object, as it were, deformed the usual position and connections of the molecules (inside the table), they, in turn, tend to return to their original state, "resist".

Absolutely any body, even a very light one (for example, a pencil lying on a table), deforms the support at the micro level. Therefore, a support reaction occurs.

There is no special formula for finding this force. They designate it with the letter, but this force is just a separate type of elastic force, so it can also be denoted as

The force is applied at the point of contact of the object with the support. Directed perpendicular to the support.

Since the body is represented as a material point, the force can be depicted from the center

Elastic force

This force arises as a result of deformation (changes in the initial state of matter). For example, when we stretch a spring, we increase the distance between the molecules of the spring material. When we compress the spring, we decrease it. When we twist or shift. In all these examples, a force arises that prevents deformation - the elastic force.

Hooke's Law

The elastic force is directed opposite to the deformation.

Since the body is represented as a material point, the force can be depicted from the center

When connected in series, for example, springs, the stiffness is calculated by the formula

When connected in parallel, the stiffness

Sample stiffness. Young's modulus.

Young's modulus characterizes the elastic properties of a substance. This is a constant value that depends only on the material, its physical state. Characterizes the ability of a material to resist tensile or compressive deformation. The value of Young's modulus is tabular.

Learn more about the properties of solids.

Body weight

Body weight is the force with which an object acts on a support. You say it's gravity! The confusion occurs in the following: indeed, often the weight of the body is equal to the force of gravity, but these forces are completely different. Gravity is the force that results from interaction with the Earth. Weight is the result of interaction with the support. The force of gravity is applied at the center of gravity of the object, while the weight is the force that is applied to the support (not to the object)!

There is no formula for determining weight. This force is denoted by the letter .

The support reaction force or elastic force arises in response to the impact of an object on a suspension or support, therefore the body weight is always numerically the same as the elastic force, but has the opposite direction.

The reaction force of the support and the weight are forces of the same nature, according to Newton's 3rd law they are equal and oppositely directed. Weight is a force that acts on a support, not on a body. The force of gravity acts on the body.

Body weight may not be equal to gravity. It can be either more or less, or it can be such that the weight is zero. This state is called weightlessness. Weightlessness is a state when an object does not interact with a support, for example, the state of flight: there is gravity, but the weight is zero!

It is possible to determine the direction of acceleration if you determine where the resultant force is directed

Note that weight is a force, measured in Newtons. How to correctly answer the question: "How much do you weigh"? We answer 50 kg, naming not weight, but our mass! In this example, our weight is equal to gravity, which is approximately 500N!

Overload- the ratio of weight to gravity

Strength of Archimedes

Force arises as a result of the interaction of a body with a liquid (gas), when it is immersed in a liquid (or gas). This force pushes the body out of the water (gas). Therefore, it is directed vertically upwards (pushes). Determined by the formula:

In the air, we neglect the force of Archimedes.

If the Archimedes force is equal to the force of gravity, the body floats. If the Archimedes force is greater, then it rises to the surface of the liquid, if it is less, it sinks.

electrical forces

There are forces of electrical origin. Occur in the presence of an electric charge. These forces, such as the Coulomb force, Ampère force, Lorentz force, are discussed in detail in the Electricity section.

Schematic designation of the forces acting on the body

Often the body is modeled by a material point. Therefore, in the diagrams, various points of application are transferred to one point - to the center, and the body is schematically depicted as a circle or rectangle.

In order to correctly designate the forces, it is necessary to list all the bodies with which the body under study interacts. Determine what happens as a result of interaction with each: friction, deformation, attraction, or maybe repulsion. Determine the type of force, correctly indicate the direction. Attention! The number of forces will coincide with the number of bodies with which the interaction takes place.

The main thing to remember

Friction forces

Distinguish between external (dry) and internal (viscous) friction. External friction occurs between solid surfaces in contact, internal friction occurs between layers of liquid or gas during their relative motion. There are three types of external friction: static friction, sliding friction and rolling friction.

Rolling friction is determined by the formula

The resistance force arises when a body moves in a liquid or gas. The magnitude of the resistance force depends on the size and shape of the body, the speed of its movement and the properties of the liquid or gas. At low speeds, the resistance force is proportional to the speed of the body

At high speeds it is proportional to the square of the speed

The relationship between gravity, the law of gravity and the acceleration of free fall

Consider the mutual attraction of an object and the Earth. Between them, according to the law of gravity, a force arises Now let's compare the law of gravity and the force of gravity

The value of free fall acceleration depends on the mass of the Earth and its radius! Thus, it is possible to calculate with what acceleration objects on the Moon or on any other planet will fall, using the mass and radius of that planet.

The distance from the center of the Earth to the poles is less than to the equator. Therefore, the acceleration of free fall at the equator is slightly less than at the poles. At the same time, it should be noted that the main reason for the dependence of the acceleration of free fall on the latitude of the area is the fact that the Earth rotates around its axis.

When moving away from the surface of the Earth, the force of gravity and the acceleration of free fall change inversely with the square of the distance to the center of the Earth.