LIGHT AND RADIO WAVES TRAVEL AT 186,000 MILES PER SECOND? (William J. Beaty)
November 15, 2010 2 Comments
No. They only travel at 186,000 miles per second while in a perfect vacuum. Light waves travel a bit slower in the air, and it travels LOTS slower when inside glass. Radio waves move much slower than 186,000 miles/sec when they travel within plastic-insulated coaxial cable. The term “speed of light” is misleading, because the complete term actually reads “speed of light in a vacuum.” There actually is no set “speed of light,” for light waves and light (and electrical energy) can travel at many different speeds depending on the medium through which the waves propagate.