Ole Rømer

Ole Rømer was a Danish astronomer, physicist and mathematician, born on 25 September 1644 in Aarhus, Denmark. He is best known for having determined the speed of light, which he discovered using a so-called penduluhr telescope and observations of Jupiter's moon Io.

Rømer was educated in Paris and then worked at the observatory in Paris. He was later appointed as an astronomer at the King's Observatory in Copenhagen, where he worked for the rest of his life.

Rømer's discovery of the speed of light was one of the most significant in early modern science and opened the way for further research into the properties of light. His work also led to the development of modern metrology, or the science of measurement.

Rømer died on 23 September 1710 in Copenhagen. He will forever be remembered for his significant contribution to the science of light and astronomy.