Relevant Pioneer Quotes – James Prescott Joule




After the knowledge of, and obedience to, the will of God, the next aim must be to know something of His attributes of wisdom, power and goodness as evidenced by His handiwork.

– James Prescott Joule, as quoted in Clifford A. Pickover’s work Archimedes to Hawking: Laws of Science and the Great Minds Behind Them (2008)



Source of Quotes/Source of Image

English physicist James Prescott Joule (1818 – 1889) contributed greatly to the world’s understanding of electricity and thermodynamics

  • In 1839, his work went a long way in establishing that various forms of energy (electrical, mechanical, and heat) are essentially the same and can be changed one into another 1

One of the foundational laws of physics (and electromagnetism) was founded and named for him, Joule’s Law:

  • “A conductor carrying a current generates heat at a rate proportional to the product of the resistance (R) of the conductor and the square of the current (I)” 2

He worked very closely with Lord Kelvin and established what proved to be a foundational concept behind thermodynamics.  This is known as the Joule-Thomson Effect:

  • “At constant temperature the internal energy of an ideal gas is independent of volume. Real gases change their internal energy with volume as a result of intermolecular forces”
  • In short, they discovered that the temperature of gas falls as it expands without any external work” 3

James Joule had a unit of electrical energy named after him, called the Joule. The Joule is equal to 1 watt-second, and 3600 joules is 1 watt-hour. 4