The speed of radio waves and the speed of light in a vacuum are the same. Both radio waves and light waves are part of the electromagnetic spectrum, which encompasses a wide range of electromagnetic waves with varying frequencies and wavelengths.
In a vacuum, electromagnetic waves, including radio waves and light waves, all travel at the speed of light, denoted by the symbol 'c'. The speed of light in a vacuum is approximately 299,792,458 meters per second (or about 186,282 miles per second).
This fundamental constant, the speed of light, represents the maximum possible speed at which information or energy can be transmitted through space. It is a fundamental property of the nature of electromagnetic waves, including radio waves and light waves. Regardless of their frequency or wavelength, all electromagnetic waves, including radio waves, travel at this constant speed when not influenced by a medium.
Therefore, when we refer to the speed of radio waves, we are essentially referring to the speed of light, as they both propagate at the same speed in a vacuum.