1676

Events in 1676 2

• 1675 – 1676 Römer measures the speed of light Light travels at finite speed — first measurement In 1675-1676, Danish astronomer Ole Rømer observed that the timing of Jupiter's moon Io eclipses varied depending on Earth's distance from Jupiter. He correctly deduced that light travels at finite speed and estimated it at approximately 220,000 km/s — within 25% of the correct value of 299,792 km/s. This was the first demonstration that light has a measurable, finite speed.
• 1676 Boyle's law and the birth of chemistry The relationship between gas pressure and volume Robert Boyle's work in the 1660s-70s, including his law (pressure and volume of a gas are inversely proportional at constant temperature), helped transform alchemy into chemistry. He defined the chemical element, insisted on experiment over theory, and demonstrated the role of air in combustion, sound, and respiration. His book The Sceptical Chymist (1661) is considered the founding document of modern chemistry.