2. It has been experimentally proven that on clean human skin in 10 minutes. 85% of pathogenic bacteria die, but only 5% in dirty bacteria.
Explain:
a) what is the reason for the death of bacteria?
b) what hygienic conclusion follows from this fact?
Explanation of hygiene requirements
1-a): Only healthy, clean skin can perform its functions normally. Proper skin care prevents skin diseases and premature aging (decrease in elasticity, formation of wrinkles and folds, deterioration of color). You should wash your face with water at room temperature, since hot water reduces elasticity and makes it flabby, and cold water disrupts the normal outflow of sebaceous gland secretions, contributes to blockage of their excretory ducts and the formation of acne.
1-b); When the integrity of the skin is damaged, bacteria enter the wound. But you should not disinfect the wound with iodine, since living skin cells - keratinocytes - are very sensitive to iodine. Therefore, it is recommended to treat only the edges of the wound with iodine.
1-c): In adolescence and adolescence, sweating increases. Often sweat develops an unpleasant odor over time. Therefore, it is necessary to regularly wash your armpits with soap, without delaying this procedure until your weekly bath.
Irregular washing of feet, rare changes of stockings and socks contribute to sweating of the feet and the appearance of a strong unpleasant odor. With constant moisture and irritation, the epidermis then loosens and can be damaged, abrasions and cracks appear through which pathogenic microorganisms penetrate into the dermis.
1-d): Underwear should provide an easy change of air under clothing. The air adjacent to the body contains carbon dioxide, evaporation of waste products from the sebaceous and sweat glands. Good breathability and hygroscopicity of underwear promotes gas exchange, removing excess harmful vapors, and maintaining a constant body temperature. Regularly changing cotton underwear promotes skin respiration and good skin condition.
1-e): Shoes should always be dry, clean and not tight. Winter shoes should be warm, as cooling the feet contributes to the occurrence of colds. Tight shoes compress the foot, deform the foot, and increase the skin's tendency to sweat. If the shoes have rubber soles, you should put a felt pad in them and make sure that they are not wet.
1st): A person’s appearance depends largely on the quality of hair. Healthy hair is soft and flexible and has shine. The main way to care for your hair is to wash it regularly. Dry hair is washed after 10 days, and oily hair is washed once a week, more often if necessary. But frequent hair washing is not recommended, as the hair becomes dry and brittle. Hypothermia of the scalp adversely affects hair growth: when walking bareheaded in cold weather, the superficial blood vessels narrow. And this disrupts hair nutrition.
When nails are trimmed irregularly, a huge number of pathogenic microorganisms accumulate under them. Therefore, nails must be trimmed carefully, observing the rules of hygiene. Fingernails should be cut in a semicircle, and toenails should be cut straight, without rounding the corners. Otherwise, the edges of the nails may cut into the nail bed and will have to be removed.
1-g): Fashion and customs often dictate styles of clothing and shoes that do not at all meet hygiene requirements. Although they provide an opportunity to somehow stand out from others and attract attention. Thus, high-heeled shoes are harmful for girls, since the incorrect position of the foot resting on the toes leads to its deformation, reduces the area of support and the stability of the body. In such shoes it is easy to twist your foot and stretch ligaments.
2-a): The bactericidal properties of dirty skin are sharply reduced; they turn out to be almost 17 times lower than those of clean skin. Only clean skin is capable of secreting a special substance - an “antibiotic” (lysozyme).
2-b): You should wash your hands, face, neck and feet with soap every morning and evening, A throughout the day - before eating and after using the toilet, as well as after interacting with animals. Each time after washing, hands must be dried dry, otherwise cracks will appear on the skin. Microbes get into them and the cracks turn red - so-called “pimples” are formed.
VII. Solving the search problem.
| Data | Causes |
| A. The color of the skin varies from person to person in shade and color. After being in the sun, a tan appears. B. Thin people freeze faster than fat people. B. With special exercises you can “achieve” greater facial expression. D. At the sight of a dog, the cat's fur ruffles. When we are cold or scared, our “hairs stand on end.” D. Examine the fingertips and the capillary lines on them. Most of the receptors in the hand are located here. E. After the bath you can “breathe easier.” G. Increased sweating reduces the load on the kidneys. | 1. Facial muscles give the face liveliness and expressiveness. By contracting, they form folds of skin that determine facial expression. 2. The skin participates in gas exchange. Skin respiration accounts for approximately 2% of total GVDOobmsna. Air enters the cavity of the sweat gland tube. 3. The function of the kidneys is partially performed by the skin. Sweat contains 98% water, 1% dissolved table salt, 1% organic matter. The composition of sweat is similar to urine, but less concentrated. 4. At the root of the hair there is a tiny muscle, the contraction of which lifts the hair. This is a vestige of those muscles that “puff up” the fur of a frightened or hypothermic animal. In such cases, a person becomes covered with goose bumps. 5. Skin color is determined by the amount of coloring pigment - melanin. With gradual exposure to ultraviolet rays, the amount of melanin increases. 6. The subcutaneous fat layer protects against cooling. 7. There are more receptors on the fingertips than on the palms. They are located in the recesses of the grooves formed by capillary lines. We usually feel objects with our fingertips; their patterns are individual for each person and are therefore used in forensic medicine. |
Correct answers: A - 5; B - 6; IN 1; G - 4; D 7; E - 2; F - 3.
VIII. To consolidate the material, the following programmed work is proposed.
Question 1. What are the functions of the skin?
Answer: a) protective, maintaining a constant composition of the internal environment of the body; b) protective, excretory, respiration, thermoregulation, receptor; c) protective, receptor, secretory, integumentary; d) protective, receptor, thermoregulation.
Question 2. What is the structure of the skin?
Answer: a) cuticle, skin itself, receptors, sebaceous and sweat glands, hair, nails; b) cuticle, skin itself (receptors, sebaceous and sweat glands, hair follicles), subcutaneous fatty tissue, hair, nails; d) cuticle, subcutaneous fatty tissue, hair, nails.
Question 3. What skin features indicate that our ancestors were mammals?
Answer: a) the presence of hair, nails, receptors, b) sweat and sebaceous glands; c) receptors in the skin; d) hair and nails.
Question 4. Which tissue forms the skin itself and which subcutaneous fatty tissue?
Answer: a) epithelial; b) connecting; c) connective and nervous; d) connective and epithelial.
Question 5. What tissue forms the cuticle?
Answer: a) epithelial; b) connecting; c) epithelial and nervous; d) nervous.
Question 6. Why do microorganisms die on clean skin?
Answer: a) the substance secreted by the skin has a detrimental effect; b) ultraviolet rays of the sun and oxygen in the air have a detrimental effect; c) there is no nutrient medium for microorganisms; d) clean skin cannot contain microorganisms.
Answers to work: 1b; 2c; 3g; 4b; 5a; 6a.
When consolidating the mother, you can also propose problematic questions:
1. Why, despite the continuous sloughing of scales, does the skin not become thinner or wear out?
2. Explain why a person in the cold, intoxicated with alcohol, freezes and dies faster than a sober person, although he initially feels warm?
3. A man lies under a blanket and trembles with chills: “It’s cold, cover it with something else!” They cover him with another blanket, but he can't get warm. The man got sick. They measure his body temperature - 39.8°. How so? The patient has a high temperature, he has a fever, but he is cold. How to explain this contradiction?
Chapter 2. Functions of the skin. skin diseases and their prevention
Functions of the skin. The cells of our body live in a liquid environment. Through blood, lymph and tissue fluid, they receive nutrients and oxygen and release decay products into them. The whole organism is in a gaseous environment, surrounded by air. The skin is the organ that separates the internal environment from the external, reliably protecting its constancy.
On the outside, the skin is covered with a thin layer of integumentary tissue - the epidermis. It consists of several layers of fairly small cells. The epidermis is followed by the skin itself - the dermis. It is mainly connective tissue. Bundles of collagen fibers give the skin strength, and elastic fibers make the skin elastic. Thanks to them, the skin of young people is elastic and elastic. In older people, elastic fibers become thinner and the skin becomes loose. The dermis is penetrated by a dense network of blood vessels and nerves. The skin itself contains muscles that can lift hair. Since the secretions of the sebaceous glands enter the hair follicles through their ducts, with every movement of the hair, the sebum is squeezed out to the surface.
Subcutaneous tissue connects the dermis to deeper lying muscles and bones. It is rich in fat cells. Adipose tissue is a reserve storage of nutrients and water and protects the body from cooling. Water is stored in numerous lymphatic vessels and capillaries, as well as in tissue fluid. There is little water in the fat cells themselves.
The first function of the skin is mechanical. The skin protects deeper tissues from damage, drying, physical, chemical and biological influences. Let us remember that the skin performs a barrier function, separating the internal environment from the continuously changing external environment. But in this case, how do the cells that directly border the air live? The cells of the most superficial layer of the epidermis are dead. Only the inner cells of the epidermis are alive. They multiply intensively, near the dermis, the same layers that are pushed closer to the surface become horny, gradually die and finally peel off. Thus, epidermal cells are continuously renewed, layer by layer.
This process occurs from the moment a person is born until his last hour and continues for some time even after death.
Sebum and sweat secreted by the sebaceous and sweat glands create an environment unfavorable for microorganisms harmful to humans and prevent the penetration of chemicals and water. However, any adaptation is relative. Some substances, including harmful ones like mercury salts, can penetrate the body through the skin. Animal and vegetable fats can also be absorbed into the skin through the openings of the sebaceous ducts. This is the basis for the use of various medicinal ointments and cosmetics.
The second function of the skin is related to thermoregulation. The skin has sweat glands. Released to the surface of the skin, sweat evaporates and cools it. Cooling of the skin is also achieved by dilating the skin blood vessels. The blood passing through them gives off part of its heat to the external environment. Constriction of blood vessels and decreased sweating help retain heat.
The third function of the skin is receptor function. In the dermis and subcutaneous tissue there are many receptors - the endings of sensitive nerve fibers and specialized formations that perceive touch, pressure, cold, heat, pain. Many receptors are involved in reflexes that protect our body from injury; through them we receive information about objects with which we come into contact. The pads of the fingers are especially sensitive to touch. There are noticeable grooves and depressions on them, forming a pattern individual for each person. Under the epidermis, at the bottom of these depressions, there are numerous receptors that perform tactile functions. Thanks to them, a person is able to subtly perceive the relief of the surface with which the fingers come into contact. This ability of the hand arose in connection with work activity.
The fourth function of the skin is excretory. Together with sweat, many liquid and gaseous substances that are harmful to the body are removed from the body: mineral salts, some metabolic products.
Finally, the skin also has a respiratory function. Carbon dioxide is removed through the sweat glands, and oxygen from the air, dissolving in the sweat fluid, penetrates the tubes of the sweat glands and is captured here by red blood cells flowing in the parietal vessels. This gas exchange is called cutaneous respiration. Its significance for the body is small, but skin breathing is beneficial for the condition of the skin itself.
Causes of skin disorders and skin damage. Usually, a distinction is made between internal and external causes that disrupt the normal condition of the skin. Internal causes may include errors in diet, contact with substances that cause allergies, disruption of hormonal regulation, and lack of vitamins.
So, too much nutrition leads to the skin turning red and taking on a greasy appearance. Consumption of alcoholic beverages changes complexion, leads to swelling and other cosmetic defects due to disruption of the functioning of skin vessels and changes in blood circulation.
Contact with allergens often causes hives and itching. Allergic reactions can be caused by eating certain foods - eggs, strawberries, oranges, inhaling pollen or the smell of fresh hay.
Skin disorders are largely determined by the state of the hormonal system. Thus, skin pigmentation depends on pituitary hormones; their absence can lead to complete discoloration of the skin. A lack of thyroid hormones makes the skin swollen, and an excess makes the skin red, hot and clammy. The skin of people suffering from diabetes is sticky, streaks of blood vessels are visible on the face, purulent infections and itching are common.
Diabetes develops when the pancreas does not produce enough hormone insulin. This leads to disruption of the constancy of the internal environment: excess glucose in the blood dehydrates tissues and disrupts liver function. At the same time, fat metabolism also suffers.
Vitamins have a strong effect on the condition of the skin. Thus, vitamin A affects the growth of nails and hair, as well as the functioning of the sebaceous and sweat glands. With a lack of vitamin A, the skin becomes dry, cracks, darkens, baldness appears, and the composition of the secretion of the sebaceous glands changes. A lack of B vitamins can lead to atrophy of the sebaceous glands, cracks in the corners of the mouth and brittle nails, and eczema. An insufficient amount of vitamin C in food leads to subcutaneous hemorrhages, roughness and pallor of the skin, and a decrease in the body’s resistance to colds.
Chapter 3. Methodological developments on the topic “Skin structure”
Lesson #1. Hardening the body. Hygiene of skin, clothing, shoes.
1. Educational:
a) Reveal the essence and role of hardening the body, its forms, conditions and physiological mechanisms.
b) Study the hygienic requirements for leather, clothing, and shoes.
2. Developmental:
a) Show the connection with the processes occurring throughout the body;
3. Educational:
a) The influence of hardening on human health, compliance with hygienic requirements for skin, clothing, and shoes.
Methods: story, conversation, student reports, defense of project work, questionnaires, testing.
Equipment: tests, quick questionnaire questions, train model, phonogram “Sounds of the Forest”, station names - “Recreation Area”, “Kozhnaya”, “Hardening Club”, “Hygienic”, “Moidodyr”, “Neboleyka”, “Bad Habits” ", posters “Skin is the mirror of the soul”, “Sun, air and water are our best friends”, etc.
During the classes.
I. Organizational moment.
II. Updating knowledge - testing.
1) Name the layers of skin.
2) What is the most important function of the skin? 3) Name the derivatives of leather.
4) In which layer of the skin are the sebaceous and sweat glands located?
III. Learning new material.
The topic and purpose of the lesson are announced.
Introductory word from the teacher.
Dear Guys!
Today we will go with you on a journey on the “Health” train. The next station is called “Recreation Area” (phonogram - “Sounds of the Forest”).
Relaxation:
Sit up straight, lower your arms along your body, close your eyes and relax. Imagine that we are now in the forest, in a forest clearing. We are caressed by the warm rays of the sun, a fresh breeze gently blows. We feel the pleasant aroma of flowers. The leaves rustle tremblingly, the birds chirp loudly. You can hear the babbling of a stream. We feel good, we feel very good! We listen, feel and enjoy!
We opened our eyes. I wish that the pleasant feelings that arose in you will continue throughout the day.
The station we are at now is called “Kozhnaya”.
Do you know that…
1. Skin mass is approximately 15% of the mass of an average 12 year old person.
2. For every 6.45 sq. see skin on average:
94 sebaceous glands;
65 hair follicles;
650 sweat glands.
3. If the skin of an adult of average height is laid out on the ground, it will take up approximately 10 square meters. m.
4. Skin has a wide range of colors due to its different melanin content, but its functions remain the same regardless of color.
5. Lips, palms, and heels are hairless. Our train leaves for the Hardening Club station.
At different times, there were various health systems and schools:
1. Competitions for young men of primitive tribes.
2. Athenian educational system.
3. Spartan education system “Severity or cruelty.”
4. Chinese gymnastics “Qigong - a method of eliminating diseases and lengthening life.”
5. Yoga is the path to improvement.
6. Knight tournaments of the Middle Ages.
7. Modern Olympic Games.
Question: Who is Porfiry Ivanov? What do you know about his followers?
A message about Porfiry Ivanov is heard.
Question: Who are walruses? Is it possible to swim in an ice hole in winter without preparation?
Speech by a student involved in winter swimming at the Walrus club.
Let's conduct a blitz survey.
1. How often have you had a cold this year:
0) never;
1) from 1 to 4 times;
2) more than 4 times.
2. Do you have chronic respiratory diseases?
1) 1 disease;
2) a complex of diseases.
3) Do you have days of general malaise (lethargy, loss of energy, drowsiness, mild headaches)?
Let's summarize the results of the quick survey.
0 - 1 point - health is fine;
2 - 4 points - you are at risk;
5 - 6 points - your body is weakened.
To prevent a person from catching a cold, he needs training in cold exposure. Our body is a hostel for microbes. The body's defenses restrain reproduction and “subversive activity.” But under unfavorable conditions, the defenses weaken and the person falls ill.
Summing up the results of the survey, we saw that among you there are people who have poor health and are susceptible to colds and illnesses.
Question: How to help yourself?
There is only one answer - hardening.
Question: What is hardening?
Question: Name the methods of hardening.
Hardening methods:
Washing your face with cold water.
Washing with cold water up to the waist.
Pouring cold water over the entire body.
Cold foot baths.
Cold and hot shower.
Swimming in a pond.
Wiping down with snow up to the waist.
Rubbing with water up to the waist.
But, starting to harden, you need to remember that...
First you need to get rid of the “microbial nest” in the body, in the form of diseased teeth, inflamed tonsils, etc.
Hardening should be gradual.
You need to harden yourself systematically, without missing a single day.
It is necessary to take into account the individual characteristics of the body.
You need to use every opportunity to harden yourself and have a good emotional mood.
Question: Name the means of hardening.
Let's hear from students:
a) Hardening with water.
b) Air hardening.
c) Sun hardening.
Now let's do the test task.
Choose the correct answer:
1. You decided to harden your body. Where do you start?
a) Consult with your doctor and parents;
b) Start pouring cold water over your entire body;
c) You will swim in the river until you freeze.
2. What time of year is it better to start hardening?
c) at any time of the year.
3. Arrange the hardening sequence in the form of a series of numbers:
1 - washing the face with cold water 2 - bathing in a pond 3 - rubbing with cold water up to the waist 4 - contrast shower 5 - dousing the body with water
(Answer - 1,3,4,5,2)
Test results (mutual verification).
Hardening rules:
Hardening procedures are carried out taking into account the health status, individual characteristics and development of the student, study conditions and extracurricular activities.
Systematic use of hardening procedures.
Gradual increase in the strength of the irritant effect.
Sequence in carrying out hardening procedures.
It's impossible to know everything, but there are some things everyone should know about skin care.
Skin is a mirror of health!!!
And now we are heading to the next station, “Gigienicheskaya”.
Student messages:
Skin hygiene.
Hair hygiene.
Foot hygiene.
Shoe hygiene.
Clothing hygiene.
Speeches by students on the project work “Profession cosmetologist”.
The next station is “Moidodyr”.
Q: The berries of this plant whiten the skin of the face, making it elastic. (strawberries).
Q: Use an infusion of the leaves of this plant to wash your hair (celandine)
Q: A decoction of this plant gives the hair a golden hue, and the skin becomes soft and velvety (chamomile flowers).
Q: Signs of which disease: redness, itching of the hands, desire to itch constantly (scabies).
Q: How to avoid sunstroke? (headdress, shadow).
Q: How to avoid head lice? (wash your hair, don’t use someone else’s comb, someone else’s bed).
The train goes to the “Bad Habits” station.
Q: A friend asks you to give her a comb.
Your actions:
a) offer a comb;
b) give it, but wash it after use;
c) politely refuse.
Q: Why can’t you exchange clothes and shoes?
(You can become infected with lice, infectious and fungal diseases).
Our train returns to the Kozhnaya station.
Assignment: I present facts, opinions about skin care. Determine what is “true” and what is “false”:
Our mood does not affect the condition of our skin and hair (lies - stress - metabolic disorders
Communication with animals does not affect the condition of human skin (false - fungal diseases, lichen)
I started going to the pool for hardening, and my nails became brittle, with a white coating (though walking barefoot means fungal diseases).
Narcotic substances make the skin ruddy and healthy (false - sharp redness and wrinkling, a person loses weight sharply).
Taking multivitamins in winter improves skin condition (true)
In the summer you need to wear synthetic clothes, it’s nice and not hot (a lie - it doesn’t allow air to pass through, the body sweats - heat stroke).
Many people's skin deteriorates when poplar and quinoa bloom (although - allergies - rash, redness of the mucous membrane).
Final words from the teacher:
We had a very interesting time and learned a lot. You are growing and changing, so you always need hygienic rules and procedures, and the choice of skin care products and medications for the treatment of skin diseases will be advised to you by cosmetologists and dermatologists, magazines “Health”, “Liza”, etc.
Homework: pp. 174 - 181, questions, RT.
Literature
1. Bayer K., Sheinberg L. Healthy lifestyle: Transl. from English Educational edition. - M.: Mir, 1997. - 368 pp., ill.
2. Belov V.I. Encyclopedia of health. Youth up to a hundred years: Reference. Ed. - M.: Chemistry, 1993. - 400 pp., ill.
4. Home hygiene guide: Ref. Ed. / Auth. Comp.V. V. Semenova, V.V. Toporkov. - St. Petersburg: Chemistry, 1995. - 304 p., ill.
5. Zaitsev G.K., Kolbanov V.V., Kolesnikova M.G. Pedagogy of health: Educational programs in valeology. - St. Petersburg: GUPM, - 1994. - 78 p.
6. Lishchuk V.A., Mostkova E.V. Nine steps to health. - M.: Eastern Book Company, 1997. - 320 p., ill. - (Episode: “Help yourself”)
7. Subject weeks at school: biology, ecology, healthy lifestyle. - Volgograd: Publishing House “Teacher”, 2001. - 153 p.
8. Kolycheva Z.I. Biochemical foundations of a healthy lifestyle. Tobolsk, TSPI named after D.I. Mendeleeva, 2000.
And shoes. CLOTHING HYGIENE. The properties of clothing are determined by the properties of the fabric, and the properties of the fabric are determined by the properties of the fibers. That is, the hygienic properties of clothing depend on the physical properties of the fabric fibers. Clothing is used by a person to protect the body from adverse environmental factors - low or high temperature, excessive solar radiation, wind, rain, snow and other meteorological and...
1-2 tbsp. spoons of dried inflorescences pour 1 glass of water and boil for 10 minutes, then, after cooling, strain. Use a cotton swab dipped in the broth to wipe your face 2-3 times a day, after washing your face. 3 TESTS TO DETERMINE YOUR SKIN TYPE TEST 1. From Oriflame This test will help you determine your skin type. 1) What will your skin look like if you treat it with cleansing milk and wash it off with water? ...
Same time. The room should be well ventilated before going to bed. The temperature in the bedroom should not exceed 18° C. Remember that your health and performance largely depend on yourself. 2. Personal hygiene of children of preschool and primary school age It is well known that human health begins in childhood. The child’s body is very plastic, it is much more sensitive to the influences of external...
Recently, Chinese physicists were able to experimentally prove the postulate of the Special Theory of Relativity, which states that nothing in our Universe can move faster than the speed of light. This happened more than a hundred years after its publication. However, their discovery shows that time travel is impossible in principle.
Let's start from afar - back in 1632, the famous Italian scientist Galileo Galilei in his book “Dialogues on the two most important systems of the world - Ptolemaic and Copernican” formulated the so-called principle of relativity, which stated that all systems are in constant motion relative to each other. This principle refuted the much more ancient statement of Aristotle that the state of rest is natural for any system, and it moves only under the influence of external factors. Galileo, for the first time in the history of science, suggested that the natural state, on the contrary, is motion. Later, several centuries later, a whole theory grew from this principle, which is now called the Special Theory of Relativity (STR).
Many non-specialists are still convinced that the author of this theory is Albert Einstein. In fact, this is not so - SRT was developed over several years by various scientists, among whom were Hendrik Lorenz, and Henri Poincaré, and Max Planck, and Hermann Minkowski. Albert Einstein enriched this theory in 1904 with two important postulates, one of which said that “each ray of light moves in a stationary coordinate system with a certain speed V, regardless of whether this ray of light is emitted by a body at rest or in motion” (although and this idea, strictly speaking, did not belong to him; Poincaré first suggested it in 1898).
However, after Einstein’s contribution, SRT took its final form, so perhaps this is why many consider him to be the creator of this theory (and, perhaps, also because Einstein later created the General Theory of Relativity (GTR), which is often confused with Special). However, nevertheless, we can safely say that the postulate of the constancy and independence of the speed of light became the cornerstone of SRT, from which almost all modern physics later grew.
Somewhat later, while working on general relativity, Einstein, taking as a basis the postulate about the speed of light, suggested that nothing in the Universe can move faster than light passing through a vacuum. Then this statement was included in all textbooks and many generations of students and schoolchildren memorized this rule by heart, in most cases without suspecting that they were not dealing with a proven postulate, but... with a hypothesis.
The fact is that for a long time this position did not have any experimental evidence, but was based only on the calculations of the great physicist (although Einstein himself, strictly speaking, did not intend to prove it experimentally, since, as we remember, he was a theoretical physicist). And if subsequently all other provisions of both STR and GTR received experimental evidence, then this statement remained a hypothesis. There is no doubt that attempts to transfer it into the category of “proven theorems” have been made more than once, but the attempts of physicists have never been crowned with success. The reason for this is the great technical complexity that arises when setting up the experiment.
In addition, throughout the twentieth century, evidence has been received that individual carriers of electromagnetic oscillations, called light waves, or, as they are also called, photons, can exceed the speed of light in a vacuum, which, as we remember, is equal to 300 thousand kilometers per hour. give me a sec. True, these were also not so much experimental data as theoretical calculations - those who expressed them relied on the long-known fact that light propagates at different speeds in different physical media. Experiments have shown that in some media (for example, in crystals), the speed of individual photons can exceed the overall speed of the light beam.
So, a very curious situation arose with the postulate about the constancy and independence of the speed of light - it could neither be proven (experimentally) nor refuted. For science, this is unacceptable - as we know, this section of human knowledge, unlike, for example, the religious worldview, does not deal with statements that are fundamentally irrefutable (and unprovable). However, since no one could offer anything better, they had to put up with this state of affairs for more than a hundred years.
And recently, finally, the postulate about the constancy and independence of the speed of light was experimentally proven. This was done by a group of physicists led by Professor Du Sheng Wang from the Hong Kong University of Science and Technology. Scientists set up an experiment in which they passed individual photons through pairs of atoms with a temperature close to absolute zero.
According to the results, the speed of photons passing through this medium, very close to the model vacuum, was significantly less than those same 300 thousand kilometers per second. In addition, the researchers measured the speed not only of the photons themselves, but also of the so-called optical precursors. Let me remind you that these are considered waves that create photons in front of them when moving in a given medium. Until now, no one has been able to measure the speed of their spread. However, physicists from Hong Kong have coped with this very difficult task for the first time.
It turned out that even the speed of propagation of those same optical predecessors is significantly lower than the speed of light in a vacuum. This suggests that not one of the substances and waves of our Universe is actually able to exceed the speed of light in a vacuum. Thus, the main postulate of SRT has received significant experimental evidence.
However, another interesting conclusion follows from this work - information, accordingly, also cannot spread faster than the speed of light (since its carriers cannot do this). Consequently, no time machine, which is supposed to work using this principle, is impossible. Dr. Du Sheng Wang said that their discovery finally buried people's hopes for the possibility of intertemporal travel.
Hundreds of thousands of physical experiments have been carried out over the thousand-year history of science. It is difficult to select a few “the very best.” A survey was conducted among physicists in the USA and Western Europe. Researchers Robert Creese and Stoney Book asked them to name the most beautiful physics experiments in history. Igor Sokalsky, a researcher at the Laboratory of High Energy Neutrino Astrophysics, Candidate of Physical and Mathematical Sciences, spoke about the experiments that were included in the top ten according to the results of a selective survey by Kriz and Buk.
1. Experiment of Eratosthenes of Cyrene
One of the oldest known physical experiments, as a result of which the radius of the Earth was measured, was carried out in the 3rd century BC by the librarian of the famous Library of Alexandria, Erastothenes of Cyrene. The experimental design is simple. At noon, on the day of the summer solstice, in the city of Siena (now Aswan), the Sun was at its zenith and objects did not cast shadows. On the same day and at the same time, in the city of Alexandria, located 800 kilometers from Siena, the Sun deviated from the zenith by approximately 7°. This is about 1/50 of a full circle (360°), which means that the circumference of the Earth is 40,000 kilometers and the radius is 6,300 kilometers. It seems almost incredible that the radius of the Earth measured by such a simple method turned out to be only 5% less than the value obtained by the most accurate modern methods, reports the Chemistry and Life website.
2. Galileo Galilei's experiment
In the 17th century, the dominant point of view was Aristotle, who taught that the speed at which a body falls depends on its mass. The heavier the body, the faster it falls. Observations that each of us can make in everyday life would seem to confirm this. Try letting go of a light toothpick and a heavy stone at the same time. The stone will touch the ground faster. Such observations led Aristotle to the conclusion about the fundamental property of the force with which the Earth attracts other bodies. In fact, the speed of falling is affected not only by the force of gravity, but also by the force of air resistance. The ratio of these forces for light objects and for heavy ones is different, which leads to the observed effect.
The Italian Galileo Galilei doubted the correctness of Aristotle's conclusions and found a way to test them. To do this, he dropped a cannonball and a much lighter musket bullet from the Leaning Tower of Pisa at the same moment. Both bodies had approximately the same streamlined shape, therefore, for both the core and the bullet, the air resistance forces were negligible compared to the forces of gravity. Galileo found that both objects reach the ground at the same moment, that is, the speed of their fall is the same.
The results obtained by Galileo are a consequence of the law of universal gravitation and the law according to which the acceleration experienced by a body is directly proportional to the force acting on it and inversely proportional to its mass.
3. Another Galileo Galilei experiment
Galileo measured the distance that balls rolling on an inclined board covered in equal intervals of time, measured by the author of the experiment using a water clock. The scientist found that if the time was doubled, the balls would roll four times further. This quadratic relationship meant that the balls moved at an accelerated rate under the influence of gravity, which contradicted Aristotle's assertion, which had been accepted for 2000 years, that bodies on which a force acts move at a constant speed, whereas if no force is applied to the body, then it is at rest. The results of this experiment by Galileo, like the results of his experiment with the Leaning Tower of Pisa, later served as the basis for the formulation of the laws of classical mechanics.
4. Henry Cavendish's experiment
After Isaac Newton formulated the law of universal gravitation: the force of attraction between two bodies with masses Mit, separated from each other by a distance r, is equal to F=γ (mM/r2), it remained to determine the value of the gravitational constant γ - To do this, it was necessary to measure the force attraction between two bodies with known masses. This is not so easy to do, because the force of attraction is very small. We feel the force of gravity of the Earth. But it is impossible to feel the attraction of even a very large mountain nearby, since it is very weak.
A very subtle and sensitive method was needed. It was invented and used in 1798 by Newton's compatriot Henry Cavendish. He used a torsion scale - a rocker with two balls suspended on a very thin cord. Cavendish measured the displacement of the rocker arm (rotation) as other balls of greater mass approached the scales. To increase sensitivity, the displacement was determined by light spots reflected from mirrors mounted on the rocker balls. As a result of this experiment, Cavendish was able to quite accurately determine the value of the gravitational constant and calculate the mass of the Earth for the first time.
5. Jean Bernard Foucault's experiment
French physicist Jean Bernard Leon Foucault experimentally proved the rotation of the Earth around its axis in 1851 using a 67-meter pendulum suspended from the top of the dome of the Parisian Pantheon. The swing plane of the pendulum remains unchanged in relation to the stars. An observer located on the Earth and rotating with it sees that the plane of rotation is slowly turning in the direction opposite to the direction of rotation of the Earth.
6. Isaac Newton's experiment
In 1672, Isaac Newton performed a simple experiment that is described in all school textbooks. Having closed the shutters, he made a small hole in them through which a ray of sunlight passed. A prism was placed in the path of the beam, and a screen was placed behind the prism. On the screen, Newton observed a “rainbow”: a white ray of sunlight, passing through a prism, turned into several colored rays - from violet to red. This phenomenon is called light dispersion.
Sir Isaac was not the first to observe this phenomenon. Already at the beginning of our era, it was known that large single crystals of natural origin have the property of decomposing light into colors. The first studies of light dispersion in experiments with a glass triangular prism, even before Newton, were carried out by the Englishman Hariot and the Czech naturalist Marzi.
However, before Newton, such observations were not subjected to serious analysis, and the conclusions drawn on their basis were not cross-checked by additional experiments. Both Hariot and Marzi remained followers of Aristotle, who argued that differences in color were determined by differences in the amount of darkness “mixed” with white light. Violet color, according to Aristotle, occurs when darkness is added to the greatest amount of light, and red - when darkness is added to the least amount. Newton carried out additional experiments with crossed prisms, when light passed through one prism then passes through another. Based on the totality of his experiments, he concluded that “no color arises from white and black mixed together, except the dark ones in between.”
the amount of light does not change the appearance of the color.” He showed that white light should be considered as a compound. The main colors are from purple to red.
This Newton experiment serves as a remarkable example of how different people, observing the same phenomenon, interpret it in different ways, and only those who question their interpretation and conduct additional experiments come to the correct conclusions.
7. Thomas Young's experiment
Until the beginning of the 19th century, ideas about the corpuscular nature of light prevailed. Light was considered to consist of individual particles - corpuscles. Although the phenomena of diffraction and interference of light were observed by Newton (“Newton’s rings”), the generally accepted point of view remained corpuscular.
Looking at the waves on the surface of the water from two thrown stones, you can see how, overlapping each other, the waves can interfere, that is, cancel out or mutually reinforce each other. Based on this, the English physicist and physician Thomas Young conducted experiments in 1801 with a beam of light that passed through two holes in an opaque screen, thus forming two independent light sources, similar to two stones thrown into water. As a result, he observed an interference pattern consisting of alternating dark and white fringes, which could not be formed if light consisted of corpuscles. The dark stripes corresponded to areas where light waves from the two slits cancel each other out. Light stripes appeared where light waves mutually reinforced each other. Thus, the wave nature of light was proven.
8. Klaus Jonsson's experiment
German physicist Klaus Jonsson conducted an experiment in 1961 similar to Thomas Young's experiment on the interference of light. The difference was that instead of rays of light, Jonsson used beams of electrons. He obtained an interference pattern similar to what Young observed for light waves. This confirmed the correctness of the provisions of quantum mechanics about the mixed corpuscular-wave nature of elementary particles.
9. Robert Millikan's experiment
The idea that the electric charge of any body is discrete (that is, consists of a larger or smaller set of elementary charges that are no longer subject to fragmentation) arose at the beginning of the 19th century and was supported by such famous physicists as M. Faraday and G. Helmholtz. The term “electron” was introduced into the theory, denoting a certain particle - the carrier of an elementary electric charge. This term, however, was purely formal at that time, since neither the particle itself nor the elementary electric charge associated with it had been discovered experimentally. In 1895, K. Roentgen, during experiments with a discharge tube, discovered that its anode, under the influence of rays flying from the cathode, was capable of emitting its own X-rays, or Roentgen rays. In the same year, French physicist J. Perrin experimentally proved that cathode rays are a stream of negatively charged particles. But, despite the colossal experimental material, the electron remained a hypothetical particle, since there was not a single experiment in which individual electrons would participate.
American physicist Robert Millikan developed a method that has become a classic example of an elegant physics experiment. Millikan managed to isolate several charged droplets of water in space between the plates of a capacitor. By illuminating with X-rays, it was possible to slightly ionize the air between the plates and change the charge of the droplets. When the field between the plates was turned on, the droplet slowly moved upward under the influence of electrical attraction. When the field was turned off, it lowered under the influence of gravity. By turning the field on and off, it was possible to study each of the droplets suspended between the plates for 45 seconds, after which they evaporated. By 1909, it was possible to determine that the charge of any droplet was always an integer multiple of the fundamental value e (electron charge). This was convincing evidence that electrons were particles with the same charge and mass. By replacing droplets of water with droplets of oil, Millikan was able to increase the duration of observations to 4.5 hours and in 1913, eliminating one by one possible sources of error, he published the first measured value of the electron charge: e = (4.774 ± 0.009)x 10-10 electrostatic units .
10. Ernst Rutherford's experiment
By the beginning of the 20th century, it became clear that atoms consist of negatively charged electrons and some kind of positive charge, due to which the atom remains generally neutral. However, there were too many assumptions about what this “positive-negative” system looks like, while there was clearly a lack of experimental data that would make it possible to make a choice in favor of one or another model. Most physicists accepted J. J. Thomson's model: the atom as a uniformly charged positive ball with a diameter of approximately 108 cm with negative electrons floating inside.
In 1909, Ernst Rutherford (assisted by Hans Geiger and Ernst Marsden) conducted an experiment to understand the actual structure of the atom. In this experiment, heavy positively charged alpha particles moving at a speed of 20 km/s passed through thin gold foil and were scattered on gold atoms, deviating from the original direction of motion. To determine the degree of deviation, Geiger and Marsden had to use a microscope to observe the flashes on the scintillator plate that occurred where the alpha particle hit the plate. Over the course of two years, about a million flares were counted and it was proven that approximately one particle in 8000, as a result of scattering, changes its direction of motion by more than 90° (that is, turns back). This could not possibly happen in Thomson’s “loose” atom. The results clearly supported the so-called planetary model of the atom - a massive tiny nucleus measuring about 10-13 cm and electrons rotating around this nucleus at a distance of about 10-8 cm.
Modern physical experiments are much more complex than experiments of the past. In some, devices are placed over areas of tens of thousands of square kilometers, in others they fill a volume of the order of a cubic kilometer. And still others will soon be carried out on other planets.
The scientist decided to test the power of prayer experimentally. The experiments lasted 15 years. This was reported by the website of the Union of Orthodox Journalists with a link from UNIAN.
The scientist reportedly took venous and capillary blood from volunteers and analyzed it. And then he asked the person being studied or someone close to him to read the prayer for 10-15 minutes, mentally or out loud. After this, venous and capillary blood were analyzed again. And she was different!
Researcher, candidate of medical sciences, author of 166 patents and 15 licenses Mikhail Lazorik, since his student years, has been studying leukocytes - these are blood cells that protect us from the penetration of pathogenic microbes. The scientist decided to study the effect of prayer on human blood.
“I myself grew up in a believing family. I never questioned the power of prayer, because faith is unproven. However, as a scientist, I had to prove this in specific studies. It is known that after prayer and church hymns a person feels peace and spiritual relief. But what happens on the physical level? in particular, with our main fluid - blood? This is what I began to study,” says the scientist.
The people who agreed to take part in the experiment were of different genders, levels of education, social status, professions, and suffered from various diseases (there was atherosclerosis, hepatitis B, and rheumatism). Before the experiment, capillary and venous blood was taken and analyzed. Then the person under study (or his acquaintance) read prayers for 15-20 minutes - these are “Our Father”, “I Believe”, “Heavenly King”, Psalm 50, to the saints, to the heavenly patrons.
After this, the venous and capillary blood was analyzed again and the quantitative and morpho-functional properties of its cells were determined. “The blood became different at the cellular level! I remember that our first subject suffered from osteomyelitis (purulent inflammation of the hip bones after a serious accident). His brother died in the accident, and the man suffered greatly from pain in his bones.
It was not he himself who read the prayer, but a specially invited one. When we compared blood indicators before and after prayer, it turned out that the level of one of the indicators of phagocytosis was 6 times lower than before the experiment! This first case only confirmed that we are on the right path,” notes Mikhail Lazorik.
All further experiments showed the same thing: after prayer, the level of infection in the body fell. Especially when it came to the acute phase of the disease. After the prayers, we recorded a change in inflammation indicators - they became lower. In each experiment, statistically significant changes in the values of individual indicators of blood cells were found, which indicates that prayers are a real factor that causes changes in the number and morphofunctional properties of blood cells.
This, in turn, is proof that prayer really affects the body at the cellular and subcellular level. “Prayer is not just words. These are vibrations of a certain frequency. It has long been proven that prayer changes the structure of water. After all, the phenomenon of blessed water for Epiphany is not a myth, but a scientific fact.
Man is almost 80% water. Therefore, by acting on the most basic fluid of our body, prayer changes it at the cellular level, even when you read it to yourself. And when it is pronounced or heard by you, the ordered sound vibrations additionally affect the human body and cause changes in blood counts, reduce inflammatory processes, and have a healing effect,” explained Mikhail Lazorik.
