In Pursuit of the Unknown: 17 Equations That Changed the World

  Ian Stewart

February 22nd 2020


In Pursuit of the Unknown: 17 Equations That Changed the World is written by the mathematician Ian Stewart and by far the most difficult book I have read. I didn't understand majority of the ideas involved in each equation. It is insane how mathematicians have come up with these equations and ideas when I can’t even understand it after being dumbed down on so many levels. Without any further ado and embarrasing myself, the following are the 17 equations.

  1. Pythagorean theorem
    Led to : surveying, navigation and more recently special and general relativity.
  2. Logarithms
    Led to : Efficient method for calculating astronomical phenomena such as eclipses and planetary orbits.
  3. Calculus
    Led to : Newton’s law of motion and differential equations.
  4. Newton's Law of Universal Gravitation
    Led to : Accurate prediction of eclipses, planetary orbits, return of comets and rotation of galaxies.
  5. Complex Numbers
    Led to : More powerful methods to understand waves, heat, electricity and magnetism. Mathematical basis for quantum mechanics.
  6. Euler's formula for polyhedra
    Led to : Topology, helps us understand how enzymes act on DNA in a cell and why motion of the celestial body can be chaotic.
  7. The Normal Distribution
    Led to : Test of the significance of experimental results such as medical trials, the concept of the ‘average man.’
  8. The Wave Equation
    Led to : Big advances in our understanding of water, sound and light waves. Oil companies use it to find oil.
  9. The Fourier transform
    Led to : Image processing and quantum mechanics. Analyze earthquakes and used in storing fingerprint data efficiently.
  10. The Navier-Stokes equations
    Led to : Modern passenger jets, fast and quiet submarines. Medical advances on blood flow in veins and arteries.
  11. Maxwell's equations
    Led to : Motivated the invention of radio, radar, television, wireless connections for computer equipment and most modern communications.
  12. Second law of thermodynamics
    Led to : Better Steam Engines, estimates of the efficiency of renewable energy. Proof that matter is made of atoms and paradoxical connections with the arrow of time.
  13. Einstein's theory of relativity
    Led to : Nuclear weapons (to some extent though not as directly as the urban myth (claims). Black holes, the Big Bang, GPS and satnav.
  14. The Schrödinger equation
    Led to : A radical revision of the physics of the world at a very small scale. Today’s computer chips and lasers wouldn’t work without it. We wouldn’t have the Avenger’s End Game.
  15. Shannon's information theory
    Led to : Efficient error-detecting and error correcting codes, used in everything from CDs to space probes.
  16. Chaos Theory
    Led to : innumerable applications throughout the sciences including the motion of planets, weather forecasting, population dynamics in ecology and earthquakes modelling.
  17. The Black–Scholes model
    Led to : Massive growth of the financial sector, surges in economic prosperity punctuated by crashes, the turbulent stock markets of the 1990s and the 2008-09 financial crisis.

Author Ian Nicholas Stewart.