I suspect this anon is concerned not to dox themself. Knowing too much about this subject might ID the anon.
^^^^ this
>mechanical
It was artificial but not necessarily mechanical.
Again for the 4th time
please see 1904 Whittaker papers
explaining how the superposition of 2 waves can create a powerful standing wave or soliton, described by non-linear optics. The transmitters can be electromagnetic but their combined function does something new that current science chooses to ignore.