Radio waves were created by men before they were “found.”
Magnetic fields are “observed” by their very measurable effects on objects.
You can’t say that about this ‘shield.’
Claiming to know where it is, even though its nature is unknown? Doesn’t make any sense! Its as though they are claiming its existence based on something they think should be coming through but isn’t.
Not exactly. It took them a while to figure out what the phenomenon was and to repeat it on purpose.
This was 'observed' by it's measurable effects on something or some radiation.
That doesn't make it 'visible'.
Invisible means something specific.
What makes you think it's nature is unknown? It is known to stop certain particles.
/johnny