The energy concept
The energy concept has a long history of development:
Isaac Newton (1642-1727) formulated laws of motion and defined
potential and kinetic energy.
Fahrenheit (F) and Celsius (C ) invented temperature scales.
A long debate took place regarding what was heat.
Quantities of heat measured, with the help of temperature scales.
Thompson (1753-1814) discovered conversion of mechanical work to heat,
while making cannons.
Thomas Young (1773-1829) coined the term
energy in 1807 from the Greek words energia
(in work) to unify many aspects of energy.
James P. Joule (1818-1889) determined energy equivalence of heat,
and work equivalence of electric energy (1 cal= 4.184 J).
Max Planck (1858-1947) explained the energy aspect of light.
Albert Einstein developed the special theory of relativity
and gave the energy equivalence of mass, E = m c2
(rest mass of electron = 511 keV).