In a vacuum, electromagnetic waves, including light waves, travel at a constant speed known as 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).
The speed of light can also be related to the wavelength (λ) and frequency (f) of the electromagnetic wave using the following formula:
c = λf
Where: c = Speed of light in a vacuum λ = Wavelength of the wave f = Frequency of the wave
This formula shows that the speed of light is equal to the product of the wavelength and the frequency of the electromagnetic wave. As a constant in a vacuum, the speed of light remains the same regardless of the wavelength or frequency of the light wave.