Energy and Human Ambitions on a Finite Planet, 2021a

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Notation
This list describes several symbols that are commonly used within the body of the book.
c
ε
Speed of light in a vacuum inertial frame: 2.99792458 × 10 8 m/s ≈ 3 × 10 8 m/s
Efficiency; typically 0 ≤ ε ≤ 1; unitless
g acceleration due to gravity: 9.8 m/s 2 or ≈10 m/s 2
h
k B
N A
ΔQ
R ⊕
R ⊙
r ⊕⊙
Planck’s constant: 6.626 × 10 −34 J · s
Boltzmann’s constant: 1.38 × 10 −23 J/K
Avogadro’s number: 6.022 × 10 23 particles per mole
Change in thermal energy,inJoules
Radius of Earth: 6,378 km
Radius of Sun: 695,700 km
Earth–Sun distance (1 AU): 149.6 million km
σ Stefan-Boltzmann constant: 5.67 × 10 −8 W/K/m 2
ΔS
ΔT
ΔW
Change in entropy,inJ/K
Change in temperature, typically in ◦ C or Kelvin (K)
Change in energy—work performed, in Joules
Scale Factor Prefixes
Factor Letter Prefix Factor Letter Prefix
10 −21 z zepto 10 21 Z zetta
10 −18 a atto 10 18 E exa
10 −15 f femto 10 15 P peta
10 −12 p pico 10 12 T tera
10 −9 n nano 10 9 G giga
10 −6 μ micro 10 6 M mega
10 −3 m milli 10 3 k kilo
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.; Freely available at:
https://escholarship.org/uc/energy_ambitions.