Is the speed of light infinite?

The speed of light is not infinite. Its determination was calculated more than three centuries ago by the Danish astronomer Ole Christensen Rømer, and celebrates today its 340th anniversary.

December 7th, 2016 | OPTIS group

The speed of light is not infinite.

In 1676, Ole Christensen Rømer, a Danish astronomer, determined for the first time a calculation to know the speed of light. He undertook experimental work based on ancient studies and theories of Empedocles, Alhazen and Roger Bacon. Studying the motion of the eclipses of lo, one of the natural satellites of Jupiter, he predicted that the next eclipse, scheduled for the 9th of November 1676, would occur ten minutes after the hour which has been deduced from the previous eclipses. Reality confirming his prediction, the astronomer was able to calculate and explain that the speed of light is such, that takes it about 22 minutes to travel the distance corresponding to the diameter of the orbit of Earth around the Sun - the exact value is now estimated at 17 minutes. He thus demonstrated the finite speed of light as opposed to the idea that light traveled instantaneously. 


The astronomer Christiaan Huygens took up the controversial theory of Rømer in his Traité de la Lumière (Treatise on Light) in 1690, in order to evaluate the speed of light - at 220 000 000 meters / second. The famous Isaac Newton then used Rømer's calculations of the finite speed of light, indicating the light would take seven or eight minutes to travel from the Sun to the Earth. James Bradley, an English astronomer, finally confirmed Rømer's theory in 1729 by explaining the astronomical phenomenon of the aberration of light. The speed of light, denoted c, has since been specified with more modern and precise tools, evaluated at 299 792 458 meters / second. 


3 centuries after, the great discoveries of these prominent scientists today enable OPTIS to offer accurate and physics-based solutions, dedicated to the simulation of any industrial optical challenge and their lit appearance.


Click here to learn more about lighting phenomena and their simulation!


Photo Credit:©