The sequence of topics in the table of contents freaked me out a little:

  III.1 Benford’s Law 135 
  III.2 Bessel Functions 137 
  III.3 The Black–Scholes Equation 137 
  III.4 The Burgers Equation 138 
  III.5 The Cahn–Hilliard Equation 138 
  III.6 The Cauchy–Riemann Equations 139 
  III.7 The Delta Function and Generalized Functions 139 
  III.8 The Diffusion Equation 142 
  III.9 The Dirac Equation 142 
  III.10 Einstein’s Field Equations 144 
  III.11 The Euler Equations 146 
  III.12 The Euler–Lagrange Equations 147 
  III.13 The Gamma Function 148

Benford's law, and then Bessel functions, and then Black-Scholes? The reason is that some sections are in alphabetical order, encyclopedia-style.

But the pace is blistering. About a half page on the Diffusion Equation.