Hugh Longbourne Callendar facts for kids
Quick facts for kids
Hugh Longbourne Callendar
|
|
|---|---|
 |
|
| Born | 18 April 1863 Hatherop, England
|
| Died | 21 January 1930 (aged 66) Ealing, England
|
| Spouse(s) | Victoria Mary Stewart |
| Children | 4, including Guy Stewart Callendar |
| Awards | Duddell Medal and Prize Rumford Medal |
| Scientific career | |
| Fields | Thermodynamics Temperature measurement Climatology X-ray imaging |
| Institutions | University of Cambridge Royal Holloway College |
Hugh Longbourne Callendar FRS (born April 18, 1863 – died January 21, 1930) was a British physicist. He is famous for his important work in measuring temperature and understanding how heat and energy work (called thermodynamics).
Callendar was the first to create a very accurate platinum resistance thermometer that scientists and engineers could actually use. This new tool helped them get consistent and correct results. He also did many experiments on thermodynamics. He created and published reliable tables about the properties of steam, which were used for important calculations. During World War I, Callendar helped the Navy by researching and developing useful tools.
He received several awards, including the Rumford Medal in 1906. He became a member of the Royal Society, a group for top scientists. Callendar was even nominated for the Nobel Prize in Physics three times!
He passed away at his home in Ealing, England, in 1930 after an operation.
Contents
Early Life and Education
Hugh Callendar was born in Hatherop, England. He was the oldest son of Reverend Hugh Callendar, a local church leader. From a young age, Hugh was very good at languages and math. He built many devices, like induction coils and generators. By age 10, he had even taught himself Morse code.
At age 11, Callendar started studying at Marlborough College. He played football and was part of the shooting and gymnastics teams.
In 1882, Callendar began studying at Trinity College, Cambridge. He first earned a top degree in Classics in 1884. Then, in 1885, he graduated with top honors in mathematics. In the same year, he started studying experimental physics at the Cavendish Laboratory. He worked under the famous physicist J. J. Thomson. Even though he had no real experience in physics, he developed his main project on platinum thermometers there. In 1886, he became a Fellow of Trinity College. While at Cambridge, he also invented a new way of writing quickly, called shorthand, which J.J. Thomson learned and used.
Family and Personal Life
Hugh Callendar married Victoria Mary Stewart in England in 1894. They had four children: a daughter named Cecil (born 1895), and three sons, Leslie Hugh (born 1896), Guy Stewart Callendar (born 1898), and Maxwell Victor (born 1905). His son, Guy Stewart, later suggested that carbon dioxide from human activities could affect the climate. This idea is sometimes called 'The Callendar Effect'.
Callendar loved cars and engines. He researched internal combustion engines. In 1902, he bought a motorcycle and made his own improvements to it. In 1904, he bought a car and changed it for family trips around England. Hugh also enjoyed astronomy, studying nature, competitive shooting, gymnastics, soccer, tennis, and making things with his hands, including car mechanics. He wrote books about his "Cursive Shorthand" and even suggested ways to change English spelling.
Career and Discoveries
Measuring Temperature Accurately
Before Callendar's work, it was hard to measure temperature very accurately and reliably. The gas thermometer was the main tool, but it was expensive and big. Mercury thermometers were also used, but they couldn't measure a wide range of temperatures and broke easily.
At Cavendish Laboratory, Callendar was advised to study how the electrical resistance of metals changes with temperature. Another scientist, Werner von Siemens, had suggested using a platinum resistance thermometer in 1860, but his device wasn't stable. Callendar created an equation that showed how the resistance of metal changed with temperature. This equation was very accurate. It helped create a standard scale for temperature that was accepted internationally in 1899.
By 1886, Callendar had designed an accurate platinum resistance thermometer. He fixed the problems Siemens had faced. His thermometer could measure temperatures from -190 °C to 660 °C with great accuracy. J. J. Thomson praised Callendar's work, saying it provided a new tool to measure temperatures "with an ease and accuracy never obtainable before." Callendar later improved his thermometer to measure temperatures from -200 °C up to 1000 °C. His design was tested thoroughly and proved to be very reliable.
Callendar’s platinum thermometer could even measure the melting point of metals. This made it useful in creating metal alloys. The Cambridge Instrument Company started making these thermometers for sale. Modern platinum thermometers are still based on Callendar’s design, with continuous improvements. His work also led to the development of rolling-chart thermometers, which can record climate temperature over time.
Even today, platinum resistance thermometers are used. They are often used to calibrate other devices because they are so accurate and stable.
Understanding Heat and Energy
From 1891 to 1893, Callendar worked as a physics professor at Royal Holloway College. In 1893, he moved to McGill University in Montreal, Canada. While at McGill, Callendar researched two main areas in thermodynamics, which is the study of how heat and energy move and change.
First, he studied steam engines with Professor John Thomas Nicolson. Second, he explored electrical and thermal units using calorimetry techniques with Howard Turner Barnes. A calorimeter is a device used to measure heat.
He also studied and published papers on the heat of gases. He calculated the boiling point of sulfur. His value was very close to the one accepted internationally years later.
Work on Steam
In 1900, Callendar developed a formula for the heat of steam. This formula showed how steam's heat changed based on pressure and temperature. He was able to get experimental results that matched his formula. From this, he created tables about the properties of steam. These tables were very important for calculations in science and engineering because there wasn't a standard set of steam tables before.
His Callendar Steam Tables were published multiple times (1915, 1922, 1927). He also published The Properties of Steam and Thermodynamic Theory of Turbines in 1920. Companies that made turbines used Callendar’s steam tables to design new steam machinery.
In 1929, Callendar and his son attended the first International Steam Conference. This meeting aimed to fix differences between steam tables used around the world. After Callendar's death, his son Guy Stewart continued his work on steam properties.
Work on Calorimetry
In 1902, Callendar and Barnes created the continuous-flow calorimeter. This device was used to measure the heat capacity of liquids. They used it to compare electrical and thermal units. They calculated a value for one calorie that is very close to the value we accept today. Callendar’s continuous-flow calorimeter was improved over time and became widely used in laboratories. It helped scientists determine the heat capacity of liquids and gases, and study combustion gases.
Other Important Work
In 1896, Callendar was the first person in Canada to perform X-ray experiments. His method produced good images that could be used in hospitals.
Later in his career, Callendar also worked on fuels. He helped write a paper in 1926 about the detonation (or explosion) of fuels. In 1927, he published another paper on the detonation of paraffin fuels.
Contributions During World War 1
During World War I, Callendar worked as a consultant for the Board of Invention and Research (BIR). He mainly helped with finding and destroying submarines.
He was also a member of the Air Inventions Committee (AIC), along with his son Guy Stewart. There, they used radiography (like X-rays) to examine equipment and aircraft engines. This helped them find defects and cracks.
Awards and Recognitions
Callendar was chosen as a Fellow of the Royal Society in 1894. He was also president of the Physical Society of London from 1910 to 1912. In 1920, he was made a Commander of the British Empire (C.B.E) for his work during World War 1. He received many other honors and awards, including:
- Watt Medal (1898)
- Rumford Medal (1906)
- Hawksley Gold Medal (1915)
- Duddell Medal and Prize (1923)
The Institute of Measurement and Control gives out The Callendar Medal each year. It is awarded for outstanding contributions to the art of instruments or measurement.
Images for kids
-
Illustration of a calorimeter by H.L. Callendar
See also
In Spanish: Hugh Longbourne Callendar para niños
