Yes, in a vacuum, all forms of electromagnetic radiation, including light, travel at the same speed, which is approximately 299,792,458 meters per second (or about 186,282 miles per second), denoted by the symbol "c." This speed is often referred to as the speed of light in a vacuum.
According to the theory of special relativity, proposed by Albert Einstein, the speed of light in a vacuum is an absolute constant and is independent of the frequency, wavelength, or energy of the light. This means that whether it is visible light, radio waves, X-rays, gamma rays, or any other form of electromagnetic radiation, they all propagate through a vacuum at the same speed.
However, it's important to note that the speed of light can be influenced by the medium through which it travels. When light passes through a material medium, such as air, water, or glass, its speed can be reduced due to interactions with atoms or molecules in the medium. This reduction in speed leads to phenomena like refraction. The speed of light in a medium is typically denoted by "v" and is slower than the speed of light in a vacuum.
In summary, while the speed of light in a vacuum is constant for all forms of electromagnetic radiation, the speed of light in a material medium can vary depending on the properties of that medium.