How We Came to Know the Cosmos:
Space & Time

by Dr Helen Klus

# Chapter 31. List of symbols

### 31.0.1 Numerical Constants

 c Speed of light = 299,792,458 m/s (first used in Chapter 7) e Elementary charge = 1.602×10-19 C (to 3dp) (first used in Chapter 13) G Gravitational constant = 6.674×10-11 m3 kg-1 s-2 (to 3dp) (first used in Chapter 5) H0 Hubble parameter = 67.8 km s-1 Mpc-1 (to 1dp) (first used in Chapter 9) h Planck’s constant = 6.626×10-34 Js (to 3 dp) (first used in Chapter 7) ħ ħ = h/2π, where h is Planck’s constant (first used in Chapter 13) me Electron mass = 9.109×10-31 kg (to 3dp) (first used in Chapter 13) π π = C/D = 3.142 (to 3 dp), where C is the circumference of a circle, C = 2πr, and D is the diameter of a circle, D = 2r (first used in Chapter 2)

### 31.0.2 Other symbols

 A Surface area (first used in Chapter 4) a Acceleration (first used in Chapter 3) ac Centripetal acceleration (first used in Chapter 3) B Magnetic field (first used in Chapter 13) C Circumference (first used in Chapter 3) D Diameter (first used in Chapter 7) d Distance (first used in Chapter 3) E Total energy (first used in Chapter 4) erel Relativistic energy (first used in Chapter 7) e0 Rest energy (first used in Chapter 7) Ecyc Cyclotron energy (first used in Chapter 13) F Force (first used in Chapter 4) Fc Centripetal force (first used in Chapter 5) GPE Gravitational potential energy (first used in Chapter 4) Gμν Einstein tensor (first used in Chapter 8) gμν Metric tensor for Minkowski space (first used in Chapter 8) g Acceleration due to gravity (first used in Chapter 2) HV Heating value (first used in Chapter 6) h Height (first used in Chapter 4) KE Kinetic energy (first used in Chapter 4) L Angular momentum (first used in Chapter 4) L Luminosity (first used in Chapter 6) ℓ Length (first used in Chapter 2) ℓrel Relativistic length (first used in Chapter 7) m Mass (first used in Chapter 4) m1 Mass of the less massive object (first used in Chapter 5) m2 Mass of the more massive object (first used in Chapter 5) n Shell number (first used in Chapter 13) P Period (first used in Chapter 2) Pr Pressure (first used in Chapter 4) p Momentum (first used in Chapter 4) Rcom Rate of combustion (first used in Chapter 6) Rμν Ricci tensor (first used in Chapter 8) r Radius (first used in Chapter 3) rSch Schwarzschild radius (first used in Chapter 14) Tμν Energy-momentum tensor (first used in Chapter 8) t Time (first used in Chapter 3) trel Relativistic time (first used in Chapter 7) V Volume (first used in Chapter 4) v Velocity (first used in Chapter 3) vesc Escape velocity (first used in Chapter 14) W Work (first used in Chapter 4) x Position (first used in Chapter 3) γ Lorentz factor (first used in Chapter 7) Δ ‘Change in’ (first used in Chapter 3) θ Angular size (first used in Chapter 30) λ Wavelength (first used in Chapter 7) ν Frequency (first used in Chapter 7) ρ Density (first used in Chapter 4) τ Torque (first used in Chapter 4) Ω Energy density (first used in Chapter 9)