In a vacuum, all types of light, regardless of their wavelengths or frequencies, travel at the same speed. According to the theory of relativity, the speed of light in a vacuum is a constant value, denoted by "c," which is approximately 299,792,458 meters per second (or about 186,282 miles per second).
This means that whether you're considering visible light, radio waves, microwaves, X-rays, or any other form of electromagnetic radiation, they all travel at the same speed when moving through a vacuum. This constant speed of light is one of the fundamental principles of physics and has been extensively confirmed by experimental observations.
However, it's important to note that when light passes through a medium other than a vacuum, such as air, water, or glass, its speed can be reduced due to interactions with the atoms or molecules in that medium. This reduction in speed is responsible for phenomena like refraction and can vary depending on the specific properties of the medium and the wavelength of light.