Short answers, pulled from the story.
Christiaan Huygens was born on the 14th of April 1629 in The Hague. He grew up in a family home that provided access to a vast library and intellectual circles including Galileo Galilei and René Descartes.
Christiaan Huygens published Theoremata de Quadratura Hyperboles Ellipsis et Circuli in 1651 followed by De Circuli Magnitudine Inventa which narrowed the calculation of pi. He later released De Ratiociniis in Ludo Aleae in 1657 introducing expected values to mathematics.
The pendulum clocks invented by Christiaan Huygens lost only about fifteen seconds per day while older verge and foliot clocks lost fifteen minutes daily. These mechanisms remained accurate enough to last almost three hundred years until the 1930s despite failures in marine use trials.
Christiaan Huygens communicated his wave theory of light to the Académie des sciences in Paris in 1678. He subsequently published this idea in Traité de la Lumière in 1690 as a treatise on light propagation.
Christiaan Huygens discovered Titan using a refracting telescope with forty-three times magnification in 1655. He also observed and sketched the Orion Nebula and estimated the Martian day at twenty-four and a half hours based on observations of Syrtis Major.