Need help understand electro magnetic waves

[Anzas]

How do electro magnetic waves travel?
if i am not mistaken waves are defiend as disturbances in a medium
so do electro magnetic waves travel through a certain medium? if so how is this medium formed or does it exist every where in the universe and does not need to be formed ?

 

[russ_watters]

Electromagnetic radiation is different from other waves in that it does not require a separate medium on which to propogate. Part of the implication of this is that the speed of light is observed to be constant by all observers regardless of a frame of reference (as opposed to the speed of the car next to yours, which depends on your speed/frame of reference).

 

[Integral]

Electromagnetic waves are self propagating. According to Maxwell's equations a Magnetic field is created by a changing Electric field, and an Electric field is created by a changing Magnetic field. This interaction propagates through space exchanging energy between the electric and magnetic fields.

 

[HallsofIvy]

"if i am not mistaken waves are defiend as disturbances in a medium"

You are mistaken. "waves" are defined as anything that obeys the "wave equation" partial differential equation. That does not require a medium.