It is a complete sentence because it has an agreeing noun and verb and isn’t missing any grammer.
"the cats fur is as smooth as silk is a metaphor
Who is Melinda and heather ??
The electromagnetic wave is self propagating, what I mean by that is, an electric field generates a magnetic field at 90 degree phase angle, and the magnetic wave you get as a result generates the electric wave at the same phase angle. The interchange of electric to magnetic and vice versa continues and lets the electromagnetic waves to travel without any medium. Quite interesting, really!
