Question

can electromagnetic waves travel in a vacuum? no, they cannot travel in a vacuum yes, they actually travel fastest in a vacuum

Explanation:

Electromagnetic waves are composed of electric and magnetic fields. They do not require a medium (like air or water) to propagate. In a vacuum, there are no particles to interfere with their movement. According to Maxwell's equations and the theory of electromagnetic radiation, the speed of electromagnetic waves in a vacuum ($c = 3\times10^{8}\ m/s$) is their maximum speed. In media with refractive index $n> 1$ (such as glass, $n\approx1.5$), the speed of electromagnetic waves is $v=\frac{c}{n}

Answer:

yes, they actually travel FASTEST in a vacuum