Measurement forms an essential part of our view of the world. Our world is measured and calibrated, and we are all subject to the tyranny of these numbers. In this updated and extended edition, the author outlines the history of measurement; particularly of the International System of units (SI). Since the previous edition, the base units of the SI have been redefined; realising a 150-year-old dream for a measurement system based on unchanging, fundamental quantities of Nature. This change has created a new SI, a Quantum-SI, which will significantly change the way we look at Nature in a quantitative manner, and greatly facilitate the advance of science. Key Features Significantly updated and extended new edition of a popular book The first book including the new quantum SI base units definitions Features wider societal and philosophical implications of a move away from physical standards Outlines the history of the science of measurement, and the origin of the Metric System More than a textbook of metrology, It is also a history of how we have arrived at the Quantum-SI
Author(s): Jeffrey H. Williams
Edition: 2
Publisher: Iop Publishing
Year: 2020
Language: English
Pages: 186
City: Bristol
PRELIMS.pdf
Preface
Acknowledgements
Author biography
Jeffrey Huw Williams
Further reading
CH001.pdf
Chapter 1 Measurement in antiquity
1.1 Man is the measure of all things
1.2 Seeds and cosmic forces
1.3 The Bronze-Age
1.4 Ancient time metrology: the calendar
1.5 The Roman Empire
Further reading
CH002.pdf
Chapter 2 Measurement in the early modern period
2.1 ‘Measured by the King’s iron rod’
2.2 Measuring the world
2.3 The pendulum: the world’s first precision measuring device
2.4 ‘Dear boy …’
Further reading
CH003.pdf
Chapter 3 Measurement in the modern world (I)
3.1 Surveying and measuring the Earth
3.2 The circumference of the Earth
3.3 The Chinese survey
3.4 La Révolution Française
3.5 Defining the size of the world
3.6 The metric survey
3.7 The error in all things
Further reading
CH004.pdf
Chapter 4 Measurement in the modern world (II)
4.1 Envy, money, terror, and the Metric System
4.2 The endgame
4.3 Avez-vous l’heure s’il vous plait?
4.4 Falling out of favour with the Metric System
Further reading
CH005.pdf
Chapter 5 Creating the language that is science
5.1 Dividing apples with oranges to make … something different
5.2 The consequences of mixing units
5.3 Derived units
5.4 A final comment on the value of a quantity
Further reading
CH006.pdf
Chapter 6 What was not in the original Metric System?
6.1 Energy, work, and power
6.2 Electricity
6.3 The molecule meme
6.4 Unit conversion in electromagnetism
Further reading
CH007.pdf
Chapter 7 Measurement in the age of scientific certainty
7.1 The Convention du mètre
7.2 Conférence générale des poids et mesures (CGPM)
7.3 Comité international des poids et mesures (CIPM)
7.4 Bureau international des poids et mesures (BIPM)
Further reading
CH008.pdf
Chapter 8 A true universal language: the SI
8.1 Even scientists cannot always agree on units
Further reading
CH009.pdf
Chapter 9 20th Century confusions and refinements in measurement
9.1 International politics
9.2 Events at the BIPM during the Fall of France, June 1940
9.3 Two peoples separated by a common system of weights and measures
Further reading
CH010.pdf
Chapter 10 The birth of the Quantum-SI
10.1 The need for change
10.2 The problem that was the kilogram
10.2.1 The ‘smoking gun’
10.3 The background to the redefinition
Further reading
CH011.pdf
Chapter 11 The base units of the Système International des Unites (I)
11.1 The base unit of length is the metre (m)
11.2 The base unit of mass is the kilogram (kg)
11.3 The base unit of electric current is the ampere (A)
11.3.1 The Kibble balance
11.4 The base unit of thermodynamic temperature is the kelvin (K)
11.4.1 The Boltzmann constant
11.5 The base unit of light intensity is the candela (cd)
11.6 The base unit of amount of substance is the mole (mol)
Further reading
CH012.pdf
Chapter 12 The base units of the Système International des Unites (II)
12.1 The base unit of time is the second (s)
12.1.1 Atomic time
12.1.2 High-resolution atomic spectroscopy and time metrology
12.1.3 The width of an observed absorption
12.1.4 Hydrogen maser
12.1.5 Caesium beam oscillator
12.1.6 Caesium fountain oscillator
12.2 The future of frequency standards
12.3 The mechanism of an optical clock
12.3.1 Femtosecond comb
12.3.2 Optical clocks
12.4 Secondary representations of the second
12.5 Possible applications of optical clocks
Further reading
CH013.pdf
Chapter 13 The new Système international des unites
13.1 Some further details of the Quantum-SI
13.2 Experimental measurements of the elementary charge, e
13.2.1 In terms of the Avogadro constant and Faraday constant
13.2.2 Oil-drop experiment
13.2.3 Shot noise
13.2.4 The Josephson and von Klitzing constants
13.3 The problem of the permeability of space in the new SI
13.4 Determination of the Planck constant
13.4.1 Josephson constant
13.4.2 Kibble balance
13.5 Measurement of NA by x-ray diffraction
Further reading
CH014.pdf
Chapter 14 For this is science
14.1 Units of measurement must evolve, because science evolves
14.2 The constants of Nature
14.3 Final thoughts on the evolution of units of measurement
