While studying the colors of light, it is very important to understand the facts about the speed of light because light exhibits different colors due to variations in its wavelength, with red light having longer wavelengths than blue light. Following are the facts which need to be understood:        Following are the facts which need to be understood: 
-    The speed of light is denoted by the symbol “c”. The constant “c” is a limiting speed, meaning nothing with mass can travel at or exceed this speed.
-    In a vacuum, the speed of light is approximately 299,792 kilometers per second (km/s) or about 186,282 miles per second (mi/s).
-    The speed of light is constant and does not depend on the motion of the source or observer. It is considered as a fundamental constant of nature.
-    Light travels in the form of electromagnetic waves. The speed of light is the fastest speed at which information or energy can travel in the universe.
-    In different mediums (like air, water, or glass), light travels at different speeds, but it is always slower than in a vacuum. The speed of light in air is slightly slower than in a vacuum, approximately 299,702 km/s. In a vacuum, light can travel around the earth’s equator about 7.5 times in one second.
-    It takes light about 8 minutes and 20 seconds to travel from the sun to earth. The time it takes for light to travel from moon to earth is about 1.28 seconds
-    The speed of light was first accurately measured by Danish astronomer Ole Romer in 1676. The metric unit for the speed of light is meters per second (m/s).