At the end of the 18th century, the famous scientists Galvani and Volta discovered electricity in animals. The first animals on which scientists experimented to confirm their discovery were frogs.Electricity generates the nerve, muscle and glandular cells of all living creatures, but this ability is most developed in fish.
It is currently known that out of 20 thousand modern fish species, about 300 are capable of creating and using bioelectric fields.
Based on the nature of the discharges generated, such fish are divided into highly electric and weakly electric. The former include freshwater South American electric eels, African electric catfish and marine electric rays. These fish generate very powerful discharges: eels, for example, with a voltage of up to 600 volts, catfish - 350. The current voltage of large sea rays is low, since sea water is a good conductor, but the current strength of their discharges, for example, the Torpedo ray, sometimes reaches 60 amperes.
Fish of the second type, for example, Mormyrus, Gnatonemus, Gymnarchus and other representatives of the beaked whales do not emit separate discharges. They send a series of almost continuous and rhythmic signals (pulses) of high frequency into the water, creating an electric field around their body. The configuration of this field appears in the form of so-called lines of force. If an object that differs in its electrical conductivity from water enters an electric field, the configuration of the field changes: objects with greater conductivity concentrate the power lilies around themselves, and those with less conductivity disperse them. Fish perceive these changes using electrical receptors, located in most fish in the head area, and determine the location of the object. Thus, these fish perform true electrical location.
Beaked fish live in Africa, in slow-moving muddy rivers, as well as in lakes and swamps, almost all of them hunt mainly at night. Some of them have poor eyesight, which is why, in the process of long evolution, these fish have developed such a perfect method for detecting food, enemies, and various objects at a distance.
The techniques used by electric fish when catching prey and defending against enemies suggest technical solutions to humans when developing installations for electrofishing and repelling fish. Modeling of electrical fish location systems opens up exceptional prospects. In modern underwater location technology, there are no search and detection systems that would work in the same way as electrolocators created in nature’s workshop. Scientists from many countries are working hard to create such equipment.
Slide 2
History of the discovery of electrical phenomena
Thales of Miletus was the first to draw attention to electric charge 600 years BC. He discovered that amber, rubbed with wool, will acquire the properties of attracting light objects: fluff, pieces of paper. Later it was believed that only amber had this property. In the middle of the 17th century, Otto von Garicke developed an electric friction machine. In addition, he discovered the property of electrical repulsion of unipolarly charged objects, and in 1729 the English scientist Stephen Gray discovered the division of bodies into conductors of electric current and insulators. Soon his colleague Robert Simmer, observing the electrification of his silk stockings, came to the conclusion that electrical phenomena are caused by the separation of bodies into positive and negative charges. When bodies rub against each other, they cause electrification of these bodies, that is, electrification is the accumulation of a charge of the same type on a body, and charges of the same sign repel, and charges of different signs attract each other and are compensated when connected, making the body neutral (uncharged). In 1729, Charles Dufay discovered that there are two types of charges. Experiments conducted by Du Fay said that one of the charges is formed by rubbing glass on silk, and the other by rubbing resin on wool. The concept of positive and negative charge was introduced by the German naturalist Georg Christoph. The first quantitative researcher was the law of interaction of charges, experimentally established in 1785 by Charles Coulomb using the sensitive torsion balance he developed.
Slide 3
Why do electrified people's hair rise up?
The hair is electrified with the same charge. As you know, like charges repel each other, so hair, like the leaves of a paper plume, diverges in all directions. If any conducting body, including a human body, is isolated from the ground, then it can be charged to a high potential. Thus, with the help of an electrostatic machine, the human body can be charged to a potential of tens of thousands of volts.
Slide 4
Does an electric charge placed on the human body in this case have an effect on the nervous system?
The human body is a conductor of electricity. If it is isolated from the ground and charged, then the charge is located exclusively on the surface of the body, so charging to a relatively high potential does not affect the nervous system, since the nerve fibers are located under the skin. The influence of an electric charge on the nervous system is felt at the moment of discharge, during which a redistribution of charges occurs on the body. This redistribution is a short-term electric current passing not along the surface, but inside the body.
Slide 5
Why do birds land on high-voltage transmission wires with impunity?
The body of a bird sitting on a wire is a branch of a circuit connected parallel to the section of the conductor between the bird’s legs. When two sections of a circuit are connected in parallel, the magnitude of the currents in them is inversely proportional to the resistance. The resistance of a bird's body is huge compared to the resistance of a short length of conductor, so the amount of current in the bird's body is negligible and harmless. It should also be added that the potential difference in the area between the bird’s legs is small.
Slide 6
Fish and electricity.
Pisces use discharges: to illuminate their path; to protect, attack and stun the victim; - transmit signals to each other and detect obstacles in advance
Slide 7
The most famous electric fish are the electric eel, electric ray and electric catfish. These fish have special organs for storing electrical energy. Small tensions arising in ordinary muscle fibers are summed up here due to the sequential inclusion of many individual elements, which are connected by nerves, like conductors, into long batteries.
Slide 8
Stingrays.
“This fish freezes the animals it wants to catch, overpowering them with the force of the blow that lives in its body.” Aristotle
Slide 9
Som.
Electrical organs are located almost along the entire length of the fish’s body and produce discharges with voltages of up to 360 V.
Slide 10
ELECTRIC EEL
The most powerful electrical organs are found in eels that live in the rivers of tropical America. Their discharges reach a voltage of 650 V.
Slide 11
Thunder is one of the most dangerous phenomena.
Thunder and lightning are one of the menacing but majestic phenomena with which man has been prepared since ancient times. A raging element. It fell upon him in the form of blinding giant lightning, menacing thunderclaps, downpour and hail. In fear of the thunderstorm, people deified it, considering it an instrument of the gods.
Slide 12
Lightning
Most often we observe lightning that resembles a winding river with tributaries. Such lightning is called linear; when discharged between clouds, their length reaches more than 20 km. Lightning of other types can be seen much less frequently. An electrical discharge in the atmosphere in the form of linear lightning is an electric current. Moreover, the current strength changes in 0.2 - 0.3 seconds. Approximately 65% of all lightning. Which we observe have a current value of 10,000 A, but rarely reach 230,000 A. The lightning channel through which the current flows becomes very hot and shines brightly. The temperature of the channel reaches tens of thousands of degrees, the pressure rises, the air expands, and it’s like an explosion of hot gases. We perceive this as thunder. A lightning strike to a ground object can cause a fire.
Slide 13
When lightning strikes, for example, a tree. It heats up, the moisture evaporates from it, and the pressure of the resulting steam and heated gases lead to destruction. To protect buildings from lightning discharges, lightning rods are used, which are a metal rod that rises above the protected object.
Slide 14
Lightning.
In deciduous trees, the current passes inside the trunk through the core, where there is a lot of sap, which boils under the influence of the current and the vapors tear the tree apart.
View all slides
Theme of my work: Living electricity
The goal of the work was to identify ways to obtain electricity from plants and experimental confirmation of some of them.
We have set ourselves the following tasks:
To achieve the objectives, the following research methods were used: literature analysis, experimental method, comparison method.
Before electric current reaches our home, it travels a long way from the place where the current is received to the place where it is consumed. Current is generated in power plants. Power plant - an electrical station, a set of installations, equipment and apparatus used directly for the production of electrical energy, as well as the necessary structures and buildings located in a certain area.
"WORK LIVE ELECTRICITY"
Ministry of Education, Science and Youth of the Republic of Crimea
Crimean competition of research works and projects for schoolchildren in grades 5-8 “Step into Science”
Topic: Living electricity
Work completed:
Asanova Evelina Asanovna
5th grade student
Scientific supervisor:
Ablyalimova Lilya Lenurovna,
biology and chemistry teacher
MBOU "Veselovskaya Secondary School"
With. Veselovka – 2017
1.Introduction……………………………………………………………..…3
2. Sources of electric current…………………………..…….……4
2.1. Non-traditional energy sources………………………….…..4
2.2. “Living” sources of electric current………………………...4
2.3. Fruits and vegetables as sources of electric current…………...5
3. Practical part……………………………..………….…………6
4. Conclusion……………………………………………………………….………..…..8
List of references……………………………………………………….9
INTRODUCTION
Electricity and plants - what could they have in common? However, back in the middle of the 18th century, natural scientists understood: these two concepts are united by some kind of internal connection.
People encountered “living” electricity at the dawn of civilization: they knew the ability of some fish to hit prey with the help of some kind of internal force. This is evidenced by cave paintings and some Egyptian hieroglyphs depicting an electric catfish. And he wasn’t the only one singled out on this basis then. Roman doctors managed to use the “strikes” of stingrays to treat nervous diseases. Scientists have done a lot in studying the amazing interaction between electricity and living things, but nature still hides a lot from us.
Thales of Miletus was the first to draw attention to electric charge 600 years BC. He discovered that amber, rubbed with wool, will acquire the properties of attracting light objects: fluff, pieces of paper. Later it was believed that only amber had this property. The first chemical source of electric current was invented by accident, at the end of the 17th century, by the Italian scientist Luigi Galvani. In fact, the goal of Galvani’s research was not at all the search for new sources of energy, but the study of the reaction of experimental animals to various external influences. In particular, the phenomenon of the generation and flow of current was discovered when strips of two different metals were attached to the frog's leg muscle. Galvani gave an incorrect theoretical explanation for the observed process. Being a doctor, not a physicist, he saw the reason in the so-called “animal electricity”. Galvani confirmed his theory with reference to well-known cases of discharges that some living beings, for example, “electric fish,” are capable of producing.
In 1729, Charles Dufay discovered that there are two types of charges. Experiments conducted by Du Fay said that one of the charges is formed by rubbing glass on silk, and the other by rubbing resin on wool. The concept of positive and negative charge was introduced by the German naturalist Georg Christoph. The first quantitative researcher was the law of interaction of charges, experimentally established in 1785 by Charles Coulomb using the sensitive torsion balance he developed.
SOURCES OF ELECTRIC CURRENT
Before electric current reaches our home, it travels a long way from the place where the current is received to the place where it is consumed. Current is generated in power plants. Power plant - an electrical station, a set of installations, equipment and apparatus used directly for the production of electrical energy, as well as the structures and buildings necessary for this, located in a certain territory. Depending on the energy source, there are thermal power plants (TPPs), hydroelectric power plants (HPPs), pumped storage power plants, and nuclear power plants (NPPs).
NON-CONVENTIONAL ENERGY SOURCES
In addition to traditional current sources, there are many non-traditional sources. Electricity, in fact, can be obtained from almost anything. Non-traditional sources of electrical energy, where irreplaceable energy resources are practically not wasted: wind energy, tidal energy, solar energy.
There are other objects that at first glance have nothing to do with electricity, but can serve as a source of current.
“LIVING” SOURCES OF ELECTRIC CURRENT
There are animals in nature that we call “living powerhouses.” Animals are very sensitive to electric current. Even a small current is fatal for many of them. Horses die even from a relatively weak voltage of 50-60 volts. And there are animals that not only have high resistance to electric current, but also generate current in their body. These fish are electric eels, stingrays, and catfish. Real living powerhouses!
The source of the current is special electrical organs located in two pairs under the skin along the body - under the caudal fin and on the upper part of the tail and back. In appearance, such organs are an oblong body, consisting of a reddish-yellow gelatinous substance, divided into several thousand flat plates, cells, longitudinal and transverse partitions. Something like a battery. More than 200 nerve fibers approach the electrical organ from the spinal cord, branches from which go to the skin of the back and tail. Touching the back or tail of this fish produces a powerful discharge that can instantly kill small animals and stun large animals and humans. Moreover, current is transmitted better in water. Large animals stunned by eels often drown in the water.
Electric organs are a means not only for protection from enemies, but also for obtaining food. Electric eels hunt at night. Approaching the prey, it randomly discharges its “batteries”, and all living things - fish, frogs, crabs - are paralyzed. The action of the discharge is transmitted over a distance of 3-6 meters. All he can do is swallow the stunned prey. Having used up the supply of electrical energy, the fish rests for a long time and replenishes it, “charging” its “batteries”.
2.3. FRUITS AND VEGETABLES AS SOURCES OF ELECTRIC CURRENT
After studying the literature, I learned that electricity can be obtained from certain fruits and vegetables. Electric current can be obtained from lemon, apples and, most interestingly, from ordinary potatoes - raw and boiled. Such unusual batteries can work for several days and even weeks, and the electricity they generate is 5-50 times cheaper than that obtained from traditional batteries and at least six times more economical than a kerosene lamp when used for lighting.
Indian scientists have decided to use fruits, vegetables and their waste to power simple household appliances. The batteries contain a paste made from processed bananas, orange peels and other vegetables or fruits, in which zinc and copper electrodes are placed. The new product is designed primarily for residents of rural areas, who can prepare their own fruit and vegetable ingredients to recharge unusual batteries.
PRACTICAL PART
Sections of leaves and stems are always negatively charged relative to normal tissue. If you take a lemon or an apple and cut it, and then apply two electrodes to the peel, they will not detect a potential difference. If one electrode is applied to the peel and the other to the inside of the pulp, a potential difference will appear, and the galvanometer will note the appearance of current.
I decided to test it experimentally and prove that there is electricity in vegetables and fruits. For research I chose the following fruits and vegetables: lemon, apple, banana, tangerine, potato. She noted the readings of the galvanometer and, indeed, received a current in each case.
As a result of the work done:
1. I studied and analyzed scientific and educational literature about sources of electric current.
2. I got acquainted with the progress of work on obtaining electric current from plants.
3. She proved that there is electricity in the fruits of various fruits and vegetables and obtained unusual current sources.
Of course, the electrical energy of plants and animals currently cannot replace full-fledged powerful energy sources. However, they should not be underestimated.
CONCLUSION
To achieve the goal of my work, all the research tasks have been solved.
Analysis of scientific and educational literature led to the conclusion that there are a lot of objects around us that can serve as sources of electric current.
During the work, methods for producing electric current were considered. I learned a lot of interesting things about traditional power sources - various kinds of power plants.
With the help of experience, I have shown that it is possible to obtain electricity from some fruits; of course, this is a small current, but the very fact of its presence gives hope that in the future such sources can be used for their own purposes (to charge a mobile phone, etc.). Such batteries can be used by residents of rural areas of the country, who can themselves prepare fruit and vegetable ingredients to recharge bio-batteries. The used battery composition does not pollute the environment like galvanic (chemical) cells and does not require separate disposal in designated areas.
LIST OF REFERENCES
Gordeev A.M., Sheshnev V.B. Electricity in plant life. Publisher: Nauka - 1991
Magazine "Science and Life", No. 10, 2004.
Magazine. "Galileo" Science by experiment. No. 3/ 2011 “Lemon Battery”.
Magazine “Young Erudite” No. 10 / 2009 “Energy from nothing.”
Galvanic cell - article from the Great Soviet Encyclopedia.
V. Lavrus “Batteries and accumulators.”
View document contents
"THESIS"
Topic: Living electricity
Scientific supervisor: Lilya Lenurovna Ablyalimova, teacher of biology and chemistry, Veselovskaya Secondary School
Relevance of the chosen topic: currently in Russia there is a trend of rising prices for energy resources, including electricity. Therefore, the issue of finding cheap energy sources is important. Humanity is faced with the task of developing environmentally friendly, renewable, non-traditional energy sources.
Purpose of the work: identifying ways to obtain electricity from plants and experimental confirmation of some of them.
Study and analyze scientific and educational literature about sources of electric current.
Familiarize yourself with the progress of work on obtaining electric current from plants.
Prove that plants have electricity.
Formulate directions for the beneficial use of the results obtained.
Research methods: literature analysis, experimental method, comparison method.
View presentation content
"PRESENTATION"
Live electricity Work completed: Asanova Evelina, 5th grade student MBOU "Veselovskaya Secondary School"
Relevance of the work:
Currently, there is a tendency in Russia to increase prices for energy resources, including electricity. Therefore, the issue of finding cheap energy sources is important.
Humanity is faced with the task of developing environmentally friendly, renewable, non-traditional energy sources.
Purpose of the work:
Identification of ways to obtain electricity from plants and experimental confirmation of some of them.
- Study and analyze scientific and educational literature about sources of electric current.
- Familiarize yourself with the progress of work on obtaining electric current from plants.
- Prove that plants have electricity.
- Formulate directions for the beneficial use of the results obtained.
- Literature analysis
- Experimental method
- Comparison method
Introduction
Our work is devoted to unusual energy sources.
Chemical current sources play a very important role in the world around us. They are used in mobile phones and spaceships, in cruise missiles and laptops, in cars, flashlights and ordinary toys. Every day we come across batteries, accumulators, and fuel cells.
Modern life is simply unthinkable without electricity - just imagine the existence of humanity without modern household appliances, audio and video equipment, an evening with a candle and a torch.
Living power plants
The most powerful discharges are produced by the South American electric eel. They reach 500-600 volts. This kind of tension can knock a horse off its feet. The eel creates a particularly strong electric current when it bends in an arc so that the victim is between its tail and head: a closed electric ring is created .
Living power plants
Stingrays are living powerhouses, producing a voltage of about 50-60 volts and delivering a discharge current of 10 amperes.
All fish that produce electrical discharges use special electrical organs for this.
Something about electric fish
Pisces use discharges:
- to illuminate your path;
- to protect, attack and stun the victim;
- transmit signals to each other and detect obstacles in advance.
Non-traditional current sources
In addition to traditional current sources, there are many non-traditional ones. It turns out that electricity can be obtained from almost anything.
Experiment:
Electricity can be obtained from some fruits and vegetables. Electric current can be obtained from lemon, apples and, most interestingly, from ordinary potatoes. I conducted experiments with these fruits and actually received a current.
- As a result of the work done:
- 1. I studied and analyzed scientific and educational literature about sources of electric current.
- 2. I got acquainted with the progress of work on obtaining electric current from plants.
- 3. She proved that there is electricity in the fruits of various fruits and vegetables and obtained unusual current sources.
CONCLUSION:
To achieve the goal of my work, all the research tasks have been solved. Analysis of scientific and educational literature led to the conclusion that there are a lot of objects around us that can serve as sources of electric current.
During the work, methods for producing electric current were considered. I learned a lot of interesting things about traditional power sources - various kinds of power plants.
Through experiments, I have shown that it is possible to obtain electricity from some fruits; of course, this is a small current, but the very fact of its presence gives hope that in the future such sources can be used for their own purposes (to charge a mobile phone, etc.). Such batteries can be used by residents of rural areas of the country, who can themselves prepare fruit and vegetable ingredients to recharge bio-batteries. The used battery composition does not pollute the environment like galvanic (chemical) cells and does not require separate disposal in designated areas.
We use it daily. It is part of our daily life, and very often the nature of this phenomenon is unknown to us. We are talking about electricity.
Few people know that this term appeared almost 500 years ago. The English physicist William Gilbert studied electrical phenomena and noticed that many objects, like amber, attract smaller particles after rubbing. Therefore, in honor of the fossil resin, he named this phenomenon electricity (from the Latin Electricus - amber). By the way, long before Gilbert, the ancient Greek philosopher Thales noticed the same properties of amber and described them. But the right to be called a discoverer still went to William Gilbert, because in science there is a tradition - whoever began to study first is the author.
The people who tamed electricity
However, things did not go further than descriptions and primitive research. Only in the 17th–18th centuries did the issue of electricity receive significant coverage in the scientific literature. Among those who, after W. Gilbert, studied this phenomenon, one can name Benjamin Franklin, who is known not only for his political career, but also for his research into atmospheric electricity.
The unit of measurement of electric charge and the law of interaction of electric charges are named after the French physicist Charles Coulomb. No less significant contributions were made by Luigi Galvani, Alessandro Volt, Michael Faraday and Andre Ampere. All these names have been known since school. Our compatriot Vasily Petrov, who discovered the voltaic arc at the beginning of the 19th century, also conducted his research in the field of electricity.
"Volta Arc"
We can say that, starting from this time, electricity ceases to be the machinations of natural forces and gradually begins to enter the lives of people, although to this day mysteries remain in this phenomenon.
We can definitely say: if electrical phenomena did not exist in nature, then it is possible that nothing like this would have been discovered until now. In ancient times, they frightened the fragile mind of man, but over time he tried to tame electricity. The results of these actions are such that it is no longer possible to imagine life without him.
Humanity was able to “tame” electricity
How does electricity manifest itself in nature?
Naturally, when the conversation turns to natural electricity, lightning immediately comes to mind. The above-mentioned American politician was the first to study them. By the way, there is a version in science that lightning had a significant impact on the development of life on Earth, since biologists have established the fact that the synthesis of amino acids requires electricity.
Lightning is a powerful discharge of electricity
Everyone knows the feeling when, when you touch someone or something, an electrical discharge occurs, causing slight inconvenience. This is a manifestation of the presence of electrical currents in the human body. By the way, the nervous system functions due to electrical impulses that come from the irritated area to the brain.
Signals are transmitted electrically within brain neurons
But not only humans generate electric currents within themselves. Many inhabitants of the seas and oceans are capable of generating electricity. For example, an electric eel is capable of creating a voltage of up to 500 volts, and the charging power of a stingray reaches 0.5 kilowatts. In addition, certain types of fish use an electric field that they create around themselves, with the help of which they can easily navigate in muddy water and at depths where sunlight does not penetrate.
Amazon River electric eel
Electricity at the service of man
All this became the prerequisites for the use of electricity for domestic and industrial purposes. Already in the 19th century, it began to be used regularly, primarily for indoor lighting. Thanks to him, it became possible to create equipment for transmitting information over vast distances using radio, television and telegraph.
Electricity for transmitting information
Nowadays it is difficult to imagine life without electric current, because all the usual devices operate exclusively on it. Apparently, this was the impetus for the creation of electrical energy storage devices (batteries) and electric generators for those places where high-voltage poles have not yet reached.
In addition, electricity is the engine of science. Many instruments that scientists use to study the world around them are also powered by it. Gradually, electricity is conquering space. Powerful batteries are installed on spaceships, and solar panels are being built on the planet and wind turbines are installed, which receive energy from nature.
Electricity engine science
And yet this phenomenon is still shrouded in mystery and darkness for many people. Even despite school education, some admit that they do not fully understand the principles of how electricity works. There are also those who are confused about the terms. They are not always able to explain the difference between voltage, power and resistance.
In living nature there are many processes associated with electrical phenomena. Let's look at some of them.
Many flowers and leaves have the ability to close and open depending on the time and day. This is caused by electrical signals representing an action potential. Leaves can be forced to close using external electrical stimuli. In addition, many plants experience damage currents. Sections of leaves and stems are always negatively charged relative to normal tissue.
If you take a lemon or an apple and cut it, and then apply two electrodes to the peel, they will not detect a potential difference. If one electrode is applied to the peel and the other to the inside of the pulp, a potential difference will appear, and the galvanometer will note the appearance of current.
The change in the potential of some plant tissues at the moment of their destruction was studied by the Indian scientist Bose. In particular, he connected the outer and inner parts of the pea with a galvanometer. He heated the pea to a temperature of up to 60C, and an electrical potential of 0.5 V was recorded. The same scientist examined a mimosa pad, which he irritated with short current pulses.
When stimulated, an action potential arose. The mimosa's reaction was not instantaneous, but delayed by 0.1 s. In addition, another type of excitation, the so-called slow wave, which appears when damaged, propagated in the mimosa pathways. This wave passes along the buds, reaching the stem, causing an action potential to occur, transmitted along the stem and leading to the lowering of nearby leaves. Mimosa reacts by moving the leaf to irritation of the pad with a current of 0.5 μA. The sensitivity of the human tongue is 10 times lower.
No less interesting phenomena related to electricity can be found in fish. The ancient Greeks were wary of meeting fish in the water, which made animals and people freeze. This fish was an electric stingray and its name was a torpedo.
The role of electricity is different in the life of different fish. Some of them use special organs to create powerful electrical discharges in the water. For example, a freshwater eel creates tension of such strength that it can repel an enemy attack or paralyze the victim. The electric organs of fish are made up of muscles that have lost the ability to contract. Muscle tissue serves as a conductor, and connective tissue serves as an insulator. Nerves from the spinal cord go to the organ. But in general it is a fine-plate structure of alternating elements. The eel has from 6,000 to 10,000 elements connected in series to form a column, and about 70 columns in each organ, located along the body.
In many fish (hymnarch, fish knife, gnatonemus), the head is charged positively and the tail is negatively charged, but in the electric catfish, on the contrary, the tail is positively charged and the head is negatively charged. Fish use their electrical properties both for attack and defense, as well as to find prey, navigate in troubled water, and identify dangerous opponents.
There are also weakly electric fish. They do not have any electrical organs. These are ordinary fish: crucian carp, carp, minnows, etc. They sense the electric field and emit a weak electrical signal.
First, biologists discovered the strange behavior of a small freshwater fish - the American catfish. He felt a metal stick approaching him in the water at a distance of several millimeters. The English scientist Hans Lissmann enclosed metal objects in paraffin or glass shells and lowered them into water, but he was unable to deceive the Nile catfish and gymnarchus. The fish felt metal. Indeed, it turned out that fish have special organs that perceive weak electric field strength.
Testing the sensitivity of electroreceptors in fish, scientists conducted an experiment. They covered the aquarium with the fish with a dark cloth or paper and moved a small magnet nearby through the air. The fish felt the magnetic field. Then the researchers simply moved their hands near the aquarium. And she reacted even to the weakest bioelectric field created by a human hand.
Fish register the electric field no worse, and sometimes even better, than the most sensitive instruments in the world and notice the slightest change in its intensity. Fish, as it turns out, are not only floating “galvanometers,” but also floating “electric generators.” They emit an electric current into the water and create an electric field around themselves that is much stronger than that that arises around ordinary living cells.
With the help of electrical signals, fish can even “talk” in a special way. Eels, for example, when they see food, begin to generate current pulses of a certain frequency, thereby attracting their fellows. And if two fish are placed in one aquarium, the frequency of their electrical discharges immediately increases.
Pisces rivals determine the strength of their opponent by the strength of the signals they emit. Other animals do not have such feelings. Why are only fish endowed with this property?
Fish live in water. Sea water is an excellent conductor. Electric waves propagate in it, without attenuation, for thousands of kilometers. In addition, fish have physiological characteristics of muscle structure, which over time have become “living generators.”
The ability of fish to accumulate electrical energy makes them ideal batteries. If it were possible to understand in more detail the details of their operation, there would be a revolution in technology in terms of creating batteries. Electrolocation and underwater communication of fish allowed the development of a system for wireless communication between a fishing vessel and a trawl.
It would be appropriate to end with a statement that was written next to an ordinary glass aquarium with an electric stingray, presented at the exhibition of the Royal Society of England in 1960. Two electrodes were lowered into the aquarium, to which a voltmeter was connected. When the fish was at rest, the voltmeter showed 0 V, when the fish was moving - 400 V. Man still cannot unravel the nature of this electrical phenomenon, observed long before the organization of the Royal Society of England. The mystery of electrical phenomena in living nature still excites the minds of scientists and requires a solution.