These firewalls retard our own discovery and advancement of knowledge with this limited perspective and limited scope of possibilities.
***You set up your own firewalls of IGNORance by IGNORing the evidence that flying saucers are just secret weapons based on suction boundary layer control experiments from almost a hundred years ago by Oscar Schrenk and Ludwig Prandtl.
https://www.amazon.com/Intercept-UFO-Renato-Vesco/dp/B001Q3ZOCY
“***You set up your own firewalls of IGNORance by IGNORing the evidence that flying saucers are just secret weapons based on suction boundary layer control experiments from almost a hundred years ago by Oscar Schrenk and Ludwig Prandtl.”
Except for the fact that these craft and entities have been documented since before any written language. They have always been here, as long as history has been recorded.