Light is slower in glass than in air. https://micro.magnet.fsu.edu/primer/java/speedoflight/index.html https://micro.magnet.fsu.edu/primer/java/speedoflight/in

Light is slower in glass than in air. https://micro.magnet.fsu.edu/primer/java/speedoflight/index.html https://micro.magnet.fsu.edu/primer/java/speedoflight/index....