The thing is, if there's no sound comng from them and no blinking lights like are requred by law, they are NOT any known airplane that is legally meant to be in the air.
And if they were military, i don't understand how they could be so damn stupid to be doing tests out in the open like that, unless they do it to be funny and intentionally cause a stir.
But if indeed it's military, id like to know how theyre flying shit that fast that doesnt make sounds.
if I had a shoulder mounted rocket i'd attempt to shoot the damn thing down even if just to see if it had any defensive capabilities. if not and it went boom, o well, then we will see what's up when it hits the ground, id be on that crash site with a vid cam like i dunno what.