We all often use such a device as a thermometer in our lives, but few people know the history of its invention and improvement. It is generally accepted that the thermometer was invented by Galileo Galilei back in 1592. The design of the thermoscope (that’s what the thermometer was called then) was primitive (see figure below): a thin glass tube was soldered to a glass ball of small diameter and placed in a liquid.

The air in the glass ball was heated by means of a burner or by simply rubbing it with the palms, as a result of which it began to displace the liquid in the glass tube, thereby showing the degree of temperature increase: the higher the air temperature in the glass ball became, the lower the water level in the tube dropped. An important role was played by the ratio of the volume of the ball to the diameter of the tube: by creating a thinner tube, it was possible to monitor more minor changes in temperature in the ball.

Subsequently, the design of Galileo's thermoscope was modified by one of his students, Fernando Medici. The basic idea remained the same, but Fernando made significant changes that made the thermoscope more similar to a modern mercury thermometer. A glass ball and a thin tube were also used (see figure above), but now the tube was soldered not from the bottom, but from the top, and the liquid was poured into the glass ball, while the top of the tube was open. Changing the temperature of the poured liquid (at that time wine alcohol was used) led to an increase in its level in the tube. Later, divisions were applied to the tube, i.e. The thermometer was first calibrated.

A lot of time has passed since then, and during this period the thermometer has been improved and modernized more than once. Recent advances in the fields of physics have enabled the development of new approaches to temperature measurement. Today, various digital thermometers have been created, which are based on the principle of changing the resistance of a substance with a change in temperature (electric thermometers) or the principle of changing the level of luminosity, spectrum and other quantities with a change in temperature (optical thermometers).

This is a thermodynamic quantity that determines the degree of heating of a body. Bodies that have a higher temperature are hotter. According to the second law of thermodynamics, spontaneous transfer of heat is possible only from bodies with a higher temperature to bodies with a lower temperature. In a state of thermal equilibrium, the temperature is equalized in all parts of an arbitrarily complex system. A measure of a change in body temperature can be a change in any property that depends on it, for example, volume, electrical resistance, etc. Most often, a change in volume is used to measure temperature. The device of thermometers is based on this. The first thermometer was invented by Galileo around 1600. Water was used as a thermometric substance, that is, a body that expands when heated. To determine body temperature, the thermometer is brought into contact with the body; Once thermal equilibrium is achieved, the thermometer shows body temperature. To change the temperature, you can use a bimetallic strip. Such a plate consists of two metals, for example, a strip of iron and a strip of zinc riveted to it. Iron and zinc expand differently. So, 1 m of iron wire when heated by 100 degrees lengthens by 1 mm, and 1 m of zinc wire - by 3 mm. Therefore, if you heat a bimetallic strip, it will begin to bend towards the iron.

Slide 2

There are many temperature scales. A device for measuring temperature was created a long time ago and it was called a thermometer.

Slide 3

An intuitive idea of temperature develops from the first days of our lives. However, the challenges facing science require increasingly precise interpretations of what we perceive with our senses. Thus, an important stage in the development of the doctrine of thermal phenomena was the identification of the difference between the concepts of “heat” and “temperature”. The first person to clearly formulate the idea of the need to distinguish them was Black. The history of the creation and use of instruments for measuring temperature - thermometers - is interesting and informative. “We must accept as one of the most general laws of heat, that “all bodies” freely communicating with each other and not subject to unequal external influences acquire the same temperature, as shown by the thermometer.” Joseph Black Today, liquid and gas thermometers, semiconductor and optical thermometers are known. And the variety of temperatures now introduced in science is great: they distinguish between electron and ion temperatures, brightness and color, noise and antenna, etc.

Slide 4

Chronology of the creation of the thermometer

In 1597, Galileo Galilei invented the first instrument for observing temperature changes (thermoscope). In 1657, Galileo's thermoscope was improved by Florentine scientists. Permanent thermometer points were established in the 18th century. In 1714, the Dutch scientist D. Fahrenheit made a mercury thermometer. In 1730, the French physicist R. Reaumur proposed an alcohol thermometer. In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale. William Thomson

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Slide 6

Different bodies expand differently when heated, so the thermometer scale depends on the thermometric substance. For practical purposes, thermometers are graded according to melting or boiling points or some other point, as long as the process occurs at a constant temperature. The most widespread is the centigrade scale (or the Celsius scale, named after the Swedish physicist who proposed it). On this scale, ice melts at 0 degrees and water boils at 100 degrees, and the distance between them is divided into one hundred parts, each of which is considered a degree. In England and the USA, the Fahrenheit scale is sometimes used, in which the melting point of ice is 32 degrees, and the boiling point of water is 212 degrees; in France, using the Reaumur scale: 0 degrees and 80, respectively. Now some practical advice. Take strips of iron and zinc about 5 mm thick, 15-20 cm long and 1 cm wide. Connect them with rivets every 1.5-2 cm. Clamp one end of the bimetallic strip in a vice and heat it over the gas. The plate will bend.

Slide 7

Invention of the thermometer

Scientists began to think about what heat is a very long time ago. Even ancient Greek philosophers pondered this question. But they were unable to express anything other than the most general assumptions. In the Middle Ages, too, almost no intelligent ideas were expressed. The doctrine of thermal phenomena began to develop only in the middle of the 18th century. The impetus for the development of this doctrine was the invention of the thermometer. Many scientists worked on the invention of the thermometer. The first of them was Galileo Galilei. At the end of the 16th century. Galileo became interested in thermal phenomena. To measure the heat of a body, Galileo decided to take advantage of the property of air to expand when heated. He took a thin glass tube, one end of which ended in a ball, and lowered the other open end into a vessel of water. At the same time, he achieved such a position that the water partially filled the tube. Now, when the air in the ball heated up or cooled down, the water level in the tube fell or rose, and by the water level one could judge the “heating” of the body. Galileo's device was very imperfect. Firstly, it was not graduated, there were no divisions on the tube. Secondly, the water level in the tube depended not only on the air temperature in the glass ball, but also on atmospheric pressure.

Slide 8

Improving the Thermometer

After Galileo, many scientists were involved in the invention of instruments with which it would be possible to determine the thermal state of bodies. Gradually the device design was improved. In the middle of the 17th century. The Florence Academy of Experience proposed the device shown in the figure. The device was a glass tube ending in a ball at the bottom. The upper end of the tube was sealed. The ball and part of the tube were filled with alcohol, and beads were placed along the tube, forming a scale for reading the temperature. The readings of this device no longer depended on the value of atmospheric pressure. There were other thermometers. In particular, one of the first designers was the Italian doctor Santorio, who used his device to measure temperature in patients. This was probably the first practical use of a thermometer. Despite the successes in the design of thermometers, these instruments were still very imperfect: a common temperature scale had not been established; for various thermometers it was set arbitrarily; different thermometers showed different temperatures under the same conditions.

Slide 9

Fahrenheit thermometer

In his last scale, the main temperature points were as follows: the temperature of the mixture of water, ice and table salt - zero degrees; the temperature of the mixture of ice and water - 32 degrees. The temperature of the human body on the Fahrenheit scale was 96 degrees. Fahrenheit considered this temperature the third main point. The boiling point of water turned out to be 180 degrees on his scale. Thermometers made by Fahrenheit gained fame and came into use. The Fahrenheit scale has been used in some countries until our time. For the first time, thermometers suitable for practical purposes began to be produced by a master glassblower from Holland Fahrenheit at the beginning of the 18th century. By this time, scientists already knew that some physical processes always occur at the same degree of heating. The Fahrenheit thermometer looked the same as a modern simple thermometer. Fahrenheit first used alcohol as an expanding body, and then, in 1714, mercury. He used different scales...

Slide 10

Reaumur and Celsius

After Fahrenheit, many other thermometer scales and designs were proposed. Of all these scales, two have survived to this day. The first scale: 0 degrees – the temperature of a mixture of water and ice and 80 degrees – the boiling point of water was proposed by the French scientist Reaumur in 1730 and bears his name. The second scale is not quite correctly named after the Swedish astronomer Celsius. Celsius in 1742 proposed a centigrade temperature scale, in which the boiling point of water was taken as 0 degrees, and the melting point of ice as 100 degrees. The modern centigrade scale, called the Celsius scale, was proposed somewhat later. As you know, it came into use and is currently used. Celsius already knew that the boiling point of water and the melting point of ice depend on air pressure. After the invention of the thermal measurement device, physicists were able to begin studying thermal phenomena.

Slide 11

It's interesting that...

...in fact, the Swedish astronomer and physicist Celsius proposed a scale in which the boiling point of water was designated by the number 0, and the melting point of ice by the number 100. Somewhat later, the Celsius scale was given a modern look by his compatriot Stroemer. ...Fahrenheit got the idea to make a thermometer himself when he read about the discovery of the French physicist Amonton, “that water boils at a fixed degree of heat.” ...by the end of the 18th century the number of temperature scales reached two dozen. ...at one time in physics laboratories they used the so-called weighing thermometer. It consisted of a hollow platinum ball filled with mercury, in which there was a capillary hole. The change in temperature was judged by the amount of mercury flowing out of the hole. ...with a decrease in the temperature of the globe by just one degree, energy would be released that would be approximately a billion times greater than that produced annually by all the power plants in the world.

Slide 12

Conclusion

The first thermometer was created in the 16th century by Galileo. The most widely used temperature scales are Fahrenheit and Celsius.

Slide 13

Sources used: B.I. Spassky “Physics in its development”, M. “Enlightenment”, 1979 “Physics for the young”, compiled by M.N. Alekseeva, M. “Enlightenment”, 1980 A.A. Leonovich “Physical Kaleidoscope”, M. “Bureau Quantum”, 1994 “Encyclopedic Dictionary of a Young Physicist”, M. “Pedagogy”, 1984

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An intuitive idea of temperature develops from the first days of our lives. However, the challenges facing science require increasingly precise interpretations of what we perceive with our senses. Thus, an important stage in the development of the doctrine of thermal phenomena was the identification of the difference between the concepts of “heat” and “temperature”. The first person to clearly formulate the idea of the need to distinguish them was Black. The history of the creation and use of instruments for measuring temperature - thermometers - is interesting and informative. Today, liquid and gas thermometers, semiconductor and optical thermometers are known. And the variety of temperatures now introduced in science is great: they distinguish between electron and ion temperatures, brightness and color, noise and antenna, etc. “We must accept as one of the most general laws of heat, that “all bodies” freely communicating with each other and not subject to unequal external influences acquire the same temperature, as shown by the thermometer.” Joseph Black Joseph Black

Chronology of the creation of the thermometer In 1597, Galileo Galilei invented the first device for observing temperature changes (thermoscope). In 1657, Galileo's thermoscope was improved by Florentine scientists. Permanent thermometer points were established in the 18th century. In 1714, the Dutch scientist D. Fahrenheit made a mercury thermometer. In 1730, the French physicist R. Reaumur proposed an alcohol thermometer. In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale. William Thomson

TEMPERATURE This is a thermodynamic quantity that determines the degree of heating of a body. Bodies that have a higher temperature are hotter. According to the second law of thermodynamics, spontaneous transfer of heat is possible only from bodies with a higher temperature to bodies with a lower temperature. In a state of thermal equilibrium, the temperature is equalized in all parts of an arbitrarily complex system. A measure of a change in body temperature can be a change in any property that depends on it, for example, volume, electrical resistance, etc. Most often, a change in volume is used to measure temperature. The device of thermometers is based on this. The first thermometer was invented by Galileo around 1600. Water was used as a thermometric substance, that is, a body that expands when heated. To determine body temperature, the thermometer is brought into contact with the body; Once thermal equilibrium is achieved, the thermometer shows body temperature. To change the temperature, you can use a bimetallic strip. Such a plate consists of two metals, for example, a strip of iron and a strip of zinc riveted to it. Iron and zinc expand differently. So, 1 m of iron wire when heated by 100 degrees lengthens by 1 mm, and 1 m of zinc wire - by 3 mm. Therefore, if you heat a bimetallic strip, it will begin to bend towards the iron.

Different bodies expand differently when heated, so the thermometer scale depends on the thermometric substance. For practical purposes, thermometers are graded according to melting or boiling points or some other point, as long as the process occurs at a constant temperature. The most widespread is the centigrade scale (or the Celsius scale, named after the Swedish physicist who proposed it). On this scale, ice melts at 0 degrees and water boils at 100 degrees, and the distance between them is divided into one hundred parts, each of which is considered a degree. In England and the USA, the Fahrenheit scale is sometimes used, in which the melting point of ice is 32 degrees, and the boiling point of water is 212 degrees; in France, using the Reaumur scale: 0 degrees and 80, respectively. Now some practical advice. Take strips of iron and zinc about 5 mm thick, cm long and 1 cm wide. Connect them with rivets every cm. Clamp one end of the bimetallic strip in a vice and heat it over the gas. The plate will bend.

Invention of the thermometer Scientists began to think about what heat is a very long time ago. Even ancient Greek philosophers pondered this question. But they were unable to express anything other than the most general assumptions. In the Middle Ages, too, almost no intelligent ideas were expressed. The doctrine of thermal phenomena began to develop only in the middle of the 18th century. The impetus for the development of this doctrine was the invention of the thermometer. Many scientists worked on the invention of the thermometer. The first of them was Galileo Galilei. At the end of the 16th century. Galileo became interested in thermal phenomena. To measure the heat of a body, Galileo decided to take advantage of the property of air to expand when heated. He took a thin glass tube, one end of which ended in a ball, and lowered the other open end into a vessel of water. At the same time, he achieved such a position that the water partially filled the tube. Now, when the air in the ball heated up or cooled down, the water level in the tube fell or rose, and by the water level one could judge the “heating” of the body. Galileo's device was very imperfect. Firstly, it was not graduated, there were no divisions on the tube. Secondly, the water level in the tube depended not only on the air temperature in the glass ball, but also on atmospheric pressure.

Improving the thermometer After Galileo, many scientists were involved in the invention of instruments with which it would be possible to determine the thermal state of bodies. Gradually the device design was improved. In the middle of the 17th century. The Florence Academy of Experience proposed the device shown in the figure. The device was a glass tube ending in a ball at the bottom. The upper end of the tube was sealed. The ball and part of the tube were filled with alcohol, and beads were placed along the tube, forming a scale for reading the temperature. The readings of this device no longer depended on the value of atmospheric pressure. There were other thermometers. In particular, one of the first designers was the Italian doctor Santorio, who used his device to measure temperature in patients. This was probably the first practical use of a thermometer. Despite the successes in the design of thermometers, these instruments were still very imperfect: a common temperature scale had not been established; for various thermometers it was set arbitrarily; different thermometers showed different temperatures under the same conditions.

Fahrenheit thermometer For the first time, thermometers suitable for practical purposes began to be produced by a master glassblower from Holland Fahrenheit at the beginning of the 18th century. By this time, scientists already knew that some physical processes always occur at the same degree of heating. The Fahrenheit thermometer looked the same as a modern simple thermometer. Fahrenheit first used alcohol as an expanding body, and then, in 1714, mercury. He used various scales. In his last scale, the main temperature points were as follows: 1. temperature of the mixture of water, ice and table salt – zero degrees 2. temperature of the mixture of ice and water – 32 degrees. The temperature of the human body on the Fahrenheit scale was 96 degrees. Fahrenheit considered this temperature the third main point. The boiling point of water turned out to be 180 degrees on his scale. Thermometers made by Fahrenheit gained fame and came into use. The Fahrenheit scale has been used in some countries until our time.

Réaumur and Celsius After Fahrenheit, many other thermometer scales and designs were proposed. Of all these scales, two have survived to this day. The first scale: 0 degrees – the temperature of a mixture of water and ice and 80 degrees – the boiling point of water was proposed by the French scientist Reaumur in 1730 and bears his name. The second scale is not quite correctly named after the Swedish astronomer Celsius. Celsius in 1742 proposed a centigrade temperature scale, in which the boiling point of water was taken as 0 degrees, and the melting point of ice as 100 degrees. The modern centigrade scale, called the Celsius scale, was proposed somewhat later. As you know, it came into use and is currently used. Celsius already knew that the boiling point of water and the melting point of ice depend on air pressure. After the invention of the thermal measurement device, physicists were able to begin studying thermal phenomena.

It is curious that... ...in fact, the Swedish astronomer and physicist Celsius proposed a scale in which the boiling point of water was designated by the number 0, and the melting point of ice by the number 100. Somewhat later, the Celsius scale was given a modern look by his compatriot Stroemer. ...Fahrenheit got the idea to make a thermometer himself when he read about the discovery of the French physicist Amonton, “that water boils at a fixed degree of heat.” ...by the end of the 18th century the number of temperature scales reached two dozen. ...at one time in physics laboratories they used the so-called weighing thermometer. It consisted of a hollow platinum ball filled with mercury, in which there was a capillary hole. The change in temperature was judged by the amount of mercury flowing out of the hole. ...with a decrease in the temperature of the globe by just one degree, energy would be released that would be approximately a billion times greater than that produced annually by all the power plants in the world.

Literature B.I. Spassky “Physics in its development”, M. “Enlightenment”, 1979 “Physics for the young”, compiled by M.N. Alekseeva, M. “Enlightenment”, 1980 A.A. Leonovich “Physical Kaleidoscope”, M. “Bureau Quantum”, 1994 “Encyclopedic Dictionary of a Young Physicist”, M. “Pedagogy”, 1984

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“We must accept as one of the most general laws of heat that “all bodies” freely communicating with each other and not subject to unequal external influences acquire the same temperature, as shown by the thermometer.” Joseph Black The intuitive idea of temperature has been formed since the first days of our lives. However, the challenges facing science require ever more precise interpretations of what we perceive with our senses. Thus, an important stage in the development of the doctrine of thermal phenomena was the identification of the difference between the concepts of “heat” and “temperature”. The first person to clearly formulate the idea of the need to distinguish them was Black. The history of the creation and use of instruments for measuring temperature - thermometers - is interesting and informative. Today, liquid and gas thermometers, semiconductor and optical thermometers are known. And the variety of temperatures now introduced in science is great: they distinguish between electron and ion temperatures, brightness and color, noise and antenna, etc.

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Slide description:

Chronology of the creation of the thermometer In 1597, Galileo Galilei invented the first device for observing temperature changes (thermoscope). In 1657, Galileo's thermoscope was improved by Florentine scientists. Constant points of the thermometer were established in the 18th century. In 1714, the Dutch scientist D. Fahrenheit made mercury thermometer. In 1730, the French physicist R. Reaumur proposed an alcohol thermometer. In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale. William Thomson

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Slide description:

Temperature This is a thermodynamic quantity that determines the degree of heating of a body. Bodies that have a higher temperature are hotter. According to the second law of thermodynamics, spontaneous transfer of heat is possible only from bodies with a higher temperature to bodies with a lower temperature. In a state of thermal equilibrium, the temperature is equalized in all parts of an arbitrarily complex system. A measure of a change in body temperature can be a change in any property that depends on it, for example, volume, electrical resistance, etc. Most often, a change in volume is used to measure temperature. The device of thermometers is based on this. The first thermometer was invented by Galileo around 1600. Water was used as a thermometric substance, that is, a body that expands when heated. To determine body temperature, the thermometer is brought into contact with the body; Once thermal equilibrium is achieved, the thermometer shows the body temperature. You can use a bimetallic strip to change the temperature. Such a plate consists of two metals, for example, a strip of iron and a strip of zinc riveted to it. Iron and zinc expand differently. So, 1 m of iron wire when heated by 100 degrees lengthens by 1 mm, and 1 m of zinc wire - by 3 mm. Therefore, if you heat a bimetallic strip, it will begin to bend towards the iron.

Slide no. 6

Slide description:

Different bodies expand differently when heated, so the thermometer scale depends on the thermometric substance. For practical purposes, thermometers are graded according to melting or boiling points or some other point, as long as the process occurs at a constant temperature. The most widespread is the centigrade scale (or the Celsius scale, named after the Swedish physicist who proposed it). On this scale, ice melts at 0 degrees and water boils at 100 degrees, and the distance between them is divided into one hundred parts, each of which is considered a degree. In England and the USA, the Fahrenheit scale is sometimes used, in which the melting point of ice is 32 degrees, and the boiling point of water is 212 degrees; in France - the Reaumur scale: 0 degrees and 80, respectively. Now some practical advice. Take strips of iron and zinc about 5 mm thick, 15-20 cm long and 1 cm wide. Connect them with rivets every 1.5-2 cm. Clamp one end of the bimetallic strip in a vice and heat it over the gas. The plate will bend.

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Slide description:

Invention of the thermometer Scientists began to think about what heat is a very long time ago. Even ancient Greek philosophers pondered this question. But they were unable to express anything other than the most general assumptions. In the Middle Ages, almost no reasonable ideas were expressed either. The doctrine of thermal phenomena began to develop only in the middle of the 18th century. The impetus for the development of this doctrine was the invention of the thermometer. Many scientists worked on the invention of the thermometer. The first of them was Galileo Galilei. At the end of the 16th century. Galileo became interested in thermal phenomena. To measure the heat of a body, Galileo decided to take advantage of the property of air to expand when heated. He took a thin glass tube, one end of which ended in a ball, and lowered the other open end into a vessel of water. At the same time, he achieved such a position that the water partially filled the tube. Now, when the air in the ball heated up or cooled down, the water level in the tube fell or rose, and by the water level one could judge the “heating” of the body. Galileo's device was very imperfect. Firstly, it was not graduated, there were no divisions on the tube. Secondly, the water level in the tube depended not only on the air temperature in the glass ball, but also on atmospheric pressure.

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Fahrenheit thermometer For the first time, thermometers suitable for practical purposes began to be produced by a master glassblower from Holland Fahrenheit at the beginning of the 18th century. By this time, scientists already knew that some physical processes always occur at the same degree of heating. The Fahrenheit thermometer looked the same as a modern simple thermometer. Fahrenheit first used alcohol as an expanding body, and then, in 1714, mercury. He used various scales.. In his last scale, the main temperature points were as follows: the temperature of the mixture of water, ice and table salt - zero degrees, the temperature of the mixture of ice and water - 32 degrees. The temperature of the human body on the Fahrenheit scale was 96 degrees. Fahrenheit considered this temperature the third main point. The boiling point of water turned out to be 180 degrees on his scale. Thermometers made by Fahrenheit gained fame and came into use. The Fahrenheit scale has been used in some countries until our time

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Slide description:

Reaumur and Celsius After Fahrenheit, many other scales and thermometer designs were proposed. Of all these scales, two have survived to this day. The first scale: 0 degrees – the temperature of a mixture of water and ice and 80 degrees – the boiling point of water, was proposed by the French scientist Reaumur in 1730 and bears his name. The second scale is not quite correctly named after the Swedish astronomer Celsius. Celsius in 1742 proposed a centigrade temperature scale, in which the boiling point of water was taken as 0 degrees, and the melting point of ice as 100 degrees. The modern centigrade scale, called the Celsius scale, was proposed a little later. As you know, it came into use and is currently used. Celsius already knew that the boiling point of water and the melting point of ice depend on air pressure. After the invention of the thermal measurement device, physicists were able to begin studying thermal phenomena.

Slide no. 11

Slide description:

It is curious that... ...in fact, the Swedish astronomer and physicist Celsius proposed a scale in which the boiling point of water was designated by the number 0, and the melting point of ice by the number 100. Somewhat later, the Celsius scale was given a modern look by his compatriot Stroemer....Fahrenheit was inspired by the idea himself make a thermometer when I read about the discovery of the French physicist Amonton, “that water boils at a fixed degree of heat.”...by the end of the 18th century, the number of temperature scales reached two dozen...at one time in physics laboratories they used the so-called gravimetric thermometer. It consisted of a hollow platinum ball filled with mercury, in which there was a capillary hole. The change in temperature was judged by the amount of mercury flowing out of the hole... lowering the temperature of the globe by just one degree would release energy that would be approximately a billion times greater than that produced annually by all the power plants in the world.