Here's why:
* Electromagnetic waves are self-propagating: They don't need a medium to travel. They consist of oscillating electric and magnetic fields that create and sustain each other.
* Speed of light in a vacuum: The speed of light in a vacuum (approximately 299,792,458 meters per second) is a fundamental constant. All electromagnetic waves, including radio waves, microwaves, visible light, X-rays, and gamma rays, travel at this speed in a vacuum.
While the frequency and wavelength of different electromagnetic waves vary, their speed in a vacuum remains constant.
