Boyle (UK)-1662 & Mariotte (FR)-1676
Ideal Gas Law: P V = RT
Amontons-1702
Absolute Zero—
Temperature at which
Pressure goes to zero at fixed Volume
Amontons
Also proposed Theory of
Friction
11/8/2011
• Daniel Gabriel Fahrenheit
(1686-1736)
• German physicist
• invented alcohol thermometer (1709)
• Hg thermometer in (1714)
• Introduced temperature scale Fahrenheit Scale-in
1724 .
Celsius Scale-1742
• On Fahrenheit scale, two very significant things for humans happened at two very insignificant points. The temperature at which water freezes is at 32 degrees and the temperature at which water boils is at 212.
• Why did Mr. F. do this?
• Why not, Celsius thought, simplify things a bit and call the freezing point zero and the boiling point
100.
Anders Celsius
Johann Lambert-1779
• In 1779 Joseph Lambert proposed a definition for absolute zero on the temperature scale that was based on the straightline relationship between the temperature and pressure of a gas.
What is the difference between this and what Amontons conjectured in 1702?
William Thomson Kelvin-1848
(1824 - 1907)
• Proposed an absolute scale of temperature in
1848.
• The absolute scale that he proposed was based on his studies of the theory of heat, in particular the theory proposed by Sadi
Carnot
It was Thomson's studies in thermodynamics though which led him to propose his absolute scale of temperature in 1848.
Kelvin is an absolute scale in that temperatures below 0K (absolute zero) do not exist anywhere in the universe. Equivalent to -273.15° Celsius or -
459.67° Fahrenheit, 0K is the temperature at which molecular energy is a minimum i.e. all molecular motion would cease.
He developed it by 'extrapolating' backwards on volume-temperature and pressure-temperature graphs. He discovered that the temperature axis was cut at -273°C. Kelvin was also aided in the developing of his scale by a 'carnot engine'. Kelvin defined his thermodynamic scale so that a Kelvin was exactly the same as one degree Celsius.
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• Invented an absolute temperature based on the interval of one degree
Fahrenheit termed the
Rankine temperature scale.
• 1850 – “ Mechanical Action of
Heat.” –formulated heat theory.
1852
11/8/2011
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