Borodina Olga 8 “A” grade, school No. 11 Teacher Bobrysheva M.S. Hypothesis The main path of development of science is not straightforward; this is typical both for science as a whole and for its individual branches. Objectives 1. Using the example of the development of ideas about temperature, trace the path of development of human thought seeking truth and methods of achieving it. 2. Find out: when and who first came up with the idea of measuring the degree of heating of bodies. 3. Monitor how quickly science received a device suitable for accurately measuring temperature. “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 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. 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 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. The most common method used to measure temperature is volume change. 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, 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. 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. the temperature of the mixture of water, ice and table salt - zero degrees 2. 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. 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 device for thermal measurements, physicists were able to begin to study 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. Conclusion The movement of science forward is not straightforward, science develops in a tortuous way, through trial and error, creating many models of Truth, but in the end only one model remains - the correct one. 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
The history of the thermometer
Prepared the presentation
student of the 10th academic class
Davydovich Yana
Thermoscope In 1592, Galileo Galilei created the first instrument for observing temperature changes, calling it a thermoscope. The thermoscope was a small glass ball with a soldered glass tube. The ball was heated and the end of the tube was dipped into water. When the ball cooled, the pressure in it decreased, and the water in the tube, under the influence of atmospheric pressure, rose to a certain height. As the weather warmed, the water level in the tubes dropped. Santorio Thermometer In 1626, an Italian scientist named Santorio from the city of Padua, who served as a professor at the local university, created his own version of the thermometer. With its help, it became possible to measure human body temperature. However, the device did not find practical application because it was extremely bulky. The device was so impressive in size that it had to be taken out into the yard to take measurements. In 1657, the Florentine Academy of Experiments 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. In 1657, the Florentine Academy of Experiments 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. Fahrenheit's thermometer In 1714, D. G. Fahrenheit made a mercury thermometer. He marked three fixed points on the scale: the bottom, 32°F, is the freezing point of the saline solution, 96°, the human body temperature, and the top, 212°F, the boiling point of water. The Fahrenheit thermometer was used in English-speaking countries until the 70s of the 20th century, and is still used in the USA. Reaumur scale Another scale was proposed by the French scientist Reaumur in 1730. He experimented with an alcohol thermometer and came to the conclusion that a scale could be constructed in accordance with the thermal expansion of alcohol. Having established that the alcohol he used, mixed with water in a ratio of 5:1, expands in a ratio of 1000:1080 when the temperature changes from the freezing point to the boiling point of water, the scientist proposed using a scale from 0 to 80 degrees. Taking the melting temperature of ice as 0°, and the boiling temperature of water at normal atmospheric pressure as 80°. Celsius scale In 1742, the Swedish scientist Andres Celsius proposed a scale for the mercury thermometer, in which the interval between the extreme points was divided into 100 degrees. At the same time, at first the boiling point of water was designated as 0°, and the melting temperature of ice as 100°. However, in this form the scale turned out to be not very convenient, and later astronomer M. Stremer and botanist K. Linnaeus decided to swap the extreme points. Kelvin scale In 1848, the English scientist Lord Kelvin proposed an absolute thermodynamic scale. At the same time, Kelvin substantiated the concept of absolute zero, denoting the temperature at which the thermal movement of molecules ceases. In Celsius it is -273.15°C. Thank you for your attention
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
Slide 5
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. Temperature
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 device for thermal measurements, physicists were able to begin to study 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
View all slides
“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,
what the thermometer shows."
Joseph Black
Intuitive understanding of temperature
develops from the first days of our life. However
the challenges facing science require more and more
accurate interpretations of what we perceive through the senses.
Thus, an important stage in the development of the doctrine of thermal
phenomena was to identify differences between concepts
"heat" and "temperature". The first one to clearly
formulated the idea of the need to distinguish them,
was Black. Interesting and informative history of creation
and the use of temperature measuring instruments –
thermometers.
Today, liquid and gas thermometers, semiconductor and
optical. And the variety of temperatures now introduced in science is great:
distinguish between electronic and ion temperatures, brightness and color,
noise and antenna, etc.
Chronology of the creation of the thermometer
In 1597, Galileo Galilei came up with the firstchange observation device
temperature (thermoscope)
In 1657, Galileo's thermoscope was
improved by Florentine
scientists.
The thermometer's constant points were
installed in the 18th century.
In 1714, the Dutch scientist D. Fahrenheit
made a mercury thermometer.
In 1730, the French physicist R. Reaumur
suggested an alcohol thermometer.
In 1848, English physicist William Thomson
(Lord Kelvin) proved the possibility
creating an absolute temperature scale.
William Thomson Temperature
This is a thermodynamic quantity that determines the degree of heating of a body. bodies,
those having a higher temperature are hotter. According to
According to the second law of thermodynamics, spontaneous heat transfer is possible
only from bodies with higher to bodies with lower temperature. Able
thermal equilibrium, the temperature is equalized in all parts arbitrarily
complex system.
A measure of changes in body temperature can be a change in any
properties that depend on it, for example volume, electrical resistance, etc.
The most common method used to measure temperature is volume change. On this
Thermometer device was founded. The first thermometer was invented by Galileo
around 1600. As a thermometric substance, i.e. a body,
expanding when heated, it used water. For determining
body temperature thermometer is brought into contact with the body; By
When thermal equilibrium is reached, the thermometer shows body temperature.
To change the temperature, you can use a bimetallic
plate. 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
not the same. So, 1 m of iron wire when heated to 100 degrees
lengthens by 1 mm, and 1 m of zinc wire - by 3 mm. Therefore, if you heat
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
For practical purposes, thermometers are graded according to melting points
or boiling or any other, as long as the process
occurred at a constant temperature. Greatest
The centigrade scale (or 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 scale is sometimes used
Fahrenheit, in which the melting point of ice is 32
degrees, and the boiling point of water is 212 degrees; in France - scale
Reaumur: 0 degrees and 80 respectively.
Now some practical advice.
Take strips of iron and zinc about 5 mm thick, length
15-20 cm and 1 cm wide. Connect them every 1.5-2 cm
with rivets. Clamp one end of the bimetallic
plate and heat it over 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 reasonable
ideas. The doctrine of thermal phenomena begins to develop only
mid-18th century The impetus for the development of this doctrine was
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
thermal phenomena. To measure the heating of a body Galileo
decided to take advantage of the property of air to expand when
heating. He took a thin glass tube, one end of which
ended in a ball, and lowered the other open end into a container with
water. At the same time, he achieved such a position that the water
partially filled the tube. Now that the air in the balloon was heating up
or cooled, the water level in the tube fell or rose, and
by the water level one could judge the “heat” of the body.
Galileo's device was very imperfect. First of all, he wasn't
graduated, there were no divisions on the tube. Secondly,
the water level in the tube depended not only on the air temperature in
glass ball, but also from atmospheric pressure.
Improving the Thermometer
After Galileo, many scientists were involved in the invention of instruments, withwith the help of 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
drawing. The device was a glass tube ending
below with a ball. The upper end of the tube was sealed. Ball and tube part
filled with alcohol, and beads were placed along the tube, forming a scale
for temperature reading. The readings of this device no longer depended on
atmospheric pressure values.
There were other thermometers. In particular, one of the first designers
there was an Italian doctor Santorio, who used his device for
measuring temperature in patients. This was probably the first practical use of a thermometer.
Despite advances in the design of thermometers, these instruments were
are still very imperfect: the general temperature has not been established
scales; for various thermometers it was set arbitrarily; different
thermometers showed different values under the same conditions
temperature.
Fahrenheit thermometer
Thermometers suitable for practical purposes for the first timebegan to be produced by a master glassblower from Holland
Fahrenheit at the beginning of the 18th century. By this time scientists had already
knew that some physical processes take place
always at the same degree of heating.
The Fahrenheit thermometer looked the same as the modern one
simple thermometer. As an expanding body
Fahrenheit first consumed alcohol, and then, in 1714, mercury.
He used different scales...
In his last scale, the main temperature points were as follows:
1. the temperature of the mixture of water, ice and table salt is zero degrees
2. the temperature of the mixture of ice and water is 32 degrees. Human temperature
body on the Fahrenheit scale turned out to be equal to 96 degrees.
Fahrenheit considered this temperature the third main point. Temperature
The boiling point of water turned out to be 180 degrees on his scale.
Thermometers made by Fahrenheit gained fame and entered into
use. The Fahrenheit scale was used in some countries until
until now
Reaumur and Celsius
Many other scales have been proposed since Fahrenheitand thermometer designs. From all these scales to ours
It's been two hours. First scale: 0 degrees – temperature
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 worn quite correctly
name of the Swedish astronomer Celsius. Celsius in 1742
proposed a centigrade temperature scale, at which 0
degrees the boiling point of water was taken, and 100
degrees – melting temperature of ice. Modern
The centigrade scale, called the Celsius scale, was
proposed a little later. As you know, she entered
used and is currently in use.
Celsius already knew that the boiling point of water and
The melting temperature of ice depends on air pressure.
After the invention of the device for thermal measurements of physics
were able to begin studying thermal phenomena.
It's interesting that...
...in fact, the Swedish astronomer and physicist Celsius proposed a scalein which the boiling point of water was designated by the number 0, and the point
melting ice - number 100. Somewhat later, the Celsius scale was given
the modern look is his compatriot Stromer.
... Fahrenheit got the idea to make a thermometer himself when he read
about the discovery of the French physicist Amonton, “that water boils at
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. About
temperature changes were judged by the amount of mercury flowing out of
holes.
…when the temperature of the globe drops by just one degree
energy would be released, approximately a billion times greater than
generated annually by all power plants in the world.
Conclusion
The first thermometer was created in16th century Galileo
Most widespread
received temperature scales
Fahrenheit and Celsius Used sources:
B.I. Spassky “Physics in its development”, M. “Prosveshcheniye”, 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
On March 29, 1561, the Italian doctor Santorio was born - one of the inventors of the first mercury thermometer, a device that was an innovation for that time and which no person can do without today. Santorio was not only a doctor, but also an anatomist and physiologist. He worked in Poland, Hungary and Croatia, actively studied the breathing process, “invisible evaporations” from the surface of the skin, and conducted research in the field of human metabolism. Santorio conducted experiments on himself and, studying the characteristics of the human body, created many measuring instruments - a device for measuring the force of pulsation of arteries, scales for monitoring changes in human weight, and the first mercury thermometer.
Three inventors It is quite difficult to say today who exactly created the thermometer. The invention of the thermometer is attributed to many scientists at once - Galileo, Santorio, Lord Bacon, Robert Fludd, Scarpi, Cornelius Drebbel, Porte and Salomon de Caus. This is due to the fact that many scientists simultaneously worked on creating a device that would help measure the temperature of air, soil, water, and humans. There is no description of this device in Galilean's own writings, but his students testified that in 1597 he created a thermoscope - an apparatus for raising water by heating. The thermoscope was a small glass ball with a glass tube soldered to it. The difference between a thermoscope and a modern thermometer is that in Galileo's invention, instead of mercury, air expanded. Also, it could only be used to judge the relative degree of heating or cooling of the body, since it did not yet have a scale. Greenhouse thermometer, 1798. Santorio from the University of Padua created his own device with which it was possible to measure the temperature of the human body, but the device was so bulky that it was installed in the courtyard of a house. Santorio's invention had the shape of a ball and an oblong winding tube on which divisions were drawn; the free end of the tube was filled with tinted liquid. His invention dates back to 1626. In 1657, Florentine scientists improved the Galileo thermoscope, in particular by equipping the device with a bead scale. Later, scientists tried to improve the device, but all thermometers were air, and their readings depended not only on changes in body temperature, but also on atmospheric pressure. The first liquid thermometers were described in 1667, but they burst if the water froze, so they began to use wine alcohol to create them. The invention of a thermometer, the data of which would not be determined by changes in atmospheric pressure, occurred thanks to the experiments of the physicist Evangelista Torricelli, a student of Galileo. As a result, the thermometer was filled with mercury, turned upside down, colored alcohol was added to the ball, and the upper end of the tube was sealed. Greenhouse thermometer, 1798. Photo:
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 first calibration of the thermometer was made.
A single scale and mercury For a long time, scientists could not find starting points, the distance between which could be divided evenly. The initial data for the scale were the thawing points of ice and melted butter, the boiling point of water, and some abstract concepts like “a significant degree of cold.” A thermometer of a modern form, most suitable for household use, with an accurate measurement scale was created by the German physicist Gabriel Fahrenheit. He described his method for creating a thermometer in 1723. Initially, Fahrenheit created two alcohol thermometers, but then the physicist decided to use mercury in the thermometer. The Fahrenheit scale was based on three established points: the first point was zero degrees - this is the temperature of the composition of water, ice and ammonia; the second, designated 32 degrees, is the temperature of the mixture of water and ice; the third, the boiling point of water, was 212 degrees. The scale was later named after its creator. But it was the Swedish astronomer, geologist and meteorologist Anders Celsius who finally established both constant points - melting ice and boiling water - in 1742. He divided the distance between points into 100 intervals, with the number 100 marking the melting point of ice, and 0 the boiling point of water. Today, the Celsius scale is used inverted, that is, the melting point of ice is taken as 0°, and the boiling point of water as 100°.
Versions. According to one version, the scale was “turned over” by his contemporaries and compatriots, the botanist Carl Linnaeus and the astronomer Morten Stremer, after the death of Celsius, but according to another, Celsius himself turned over his scale on Stremer’s advice. In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale, where the reference point is the value of absolute zero: -273.15 ° C - at this temperature further cooling of bodies is no longer possible. Already in the middle of the 18th century, thermometers became an item of trade, and they were made by artisans, but thermometers came to medicine much later, in the middle of the 19th century.
Modern thermometers If in the 18th century there was a “boom” of discoveries in the field of temperature measurement systems, today work is increasingly underway to create methods for measuring temperature. The scope of application of thermometers is extremely wide and is of particular importance for modern human life. A thermometer outside the window reports the temperature outside, a thermometer in the refrigerator helps control the quality of food storage, a thermometer in the oven allows you to maintain the temperature when baking, and a thermometer measures body temperature and helps assess the causes of poor health. A thermometer is the most common type of thermometer, and it is the one that can be found in every home. However, mercury thermometers, which were once a brilliant discovery by scientists, are now gradually becoming a thing of the past as unsafe. Mercury thermometers contain 2 grams of mercury and have the highest accuracy in determining temperature, but you not only need to handle them correctly, but also know what to do if the thermometer suddenly breaks. Read more about how to properly dispose of mercury from a thermometer. Mercury thermometers are being replaced by electronic or digital thermometers, which operate on the basis of a built-in metal sensor. There are also special thermal strips and infrared thermometers.
