In science, Christian Huygens (1629-1695) was a Dutch physicist noted for his 1669 determination that the quantity of the mass of an object multiplied by its velocity squared mv² remains constant during perfectly elastic collisions, such as between steel balls, and for his 1674 work with French physicist Denis Papin on vacuum pumps. Huygens’ quantity was later called vis viva by German mathematician Gottfried Leibniz in 1886. [1]

Vacuum pump
In circa 1645, German engineer Otto Guericke invented a vacuum pump to disprove Greek philosopher Parmenides' circa 485 BC hypothesis that “nature abhorred a vacuum”. The invention was described in the 1657 book Mechanical Hydraulic Pneumatics by German scientist Gaspar Schott, a correspondent of Guericke. [2] Among those to have read the book were Huygens and his associate Irish physicist Robert Boyle, who each built or acquired pumps of their own.

Some time prior to 1674, French physicist Denis Papin moved to Paris and assisted Huygens in his experiments with the air-pump and gunpowder piston and cylinder engines, the results of which (Experiences du Vuide) were published at Paris in that year, and also in the form of five papers by Huygens and Papin jointly, in the Philosophical Transactions for 1675. This association was a precursor to Papin’s later invention of the first steam engine in 1690.

References
1. Hokikian, Jack. (2002). The Science of Disorder: Understanding the Complexity, Uncertainty, and Pollution in Our World (pg. 3-4). Los Feliz Publishing.
2. Schott, Gaspar. (1657). Mechanical Hydraulic Pneumatics (Mechanicahydraulica-pneumatica). Würtzburg.

External links
● Christiaan Huygens – Wikipedia.