The beginning of the 2nd video already cuts some stuff about aerodynamics, plus, some things they say are not totally acurate.
Like, the negative dihedral on the bird is actually against the stability of such gliders. It's only useful in some designs which are not related to such a glider. Also, all planes don't have a fin like they say. Some complex ones don't have one, just like birds (like the B2). And they say they could have been launched by a catapult, but there is no way it would launch even a modern glider with enough potential energy (modern catapults are 1 to 2000m long to have the glider reach 400m of altitude which is needed in order to have enough time to). To balance the fact it wouldn't be left at such an altitude, it would need a crazy fast release speed to give it enough energy to go that high (a totally irrealistic one). So maybe they have attempted that, but it has certainly failed, and surely killed the pilots if there were some.
Also they totally forgot to talke about the most important part : the controls
I believe the crafter of those toys had a certain understanding of basic aerodynamics (and it just needs experimenting with paper for some time) but imagining they have made gliders is not realistic, not with the info we have at least.
It's not the idea itself that is bad, it's the way it's totally biased which is not, and the fact they keep with their "scientific" attitude, which would require more objectivity in the way they talk about a subject.
Also, no, the space shuttle design is NOT intended to fly in relative high airspeed. It actually glides at around a few hundreds of mph only (a war war II plane with regular wings actually fly faster, in equivalent airspeed) (don't remember the value but it's not really more than that of indicated in the space shuttle) in equivalent airspeed which is equivalent to a ground speed of several thousands mph to 300 at sea level because of the density of the air to be really low at 100km of altitude. The actual goal of the shuttle during the reentry into the atmosphere is to break its kinetic energy by having totally crazy angle of attach and bank angles (like, 70 degrees from the balistic direction) thus creating only friction and therefore drag, and if it keeps too much speed, it means it's creating lift and so it's not doing good, and it would bounce on the atmosphere and be lost in space. Aerodynamically, from the beginning to the end it glides more or less at the same speed, and its design which is more or less the same as a brick with tiny wings makes it possible to have stupid angles and not explode, and be able smoothly to recover from it. It's the relative high speed to the air molecules that cause temperature rise and thereferore those crazy "flames" during the reentry. On an aerodynamical level, the space shuttle does nothing "that" complicated, it's even designed to be manually controlled (and out of the hundreds times it came back to earth, I think it happened once and went well). It's the technicall challenge to make it able to stand those temperatures as well, and the computer calculations, that were totally awesome.
The argument of the engineer is valid, but not the way he explains it with the shuttle, at least the way he tries to say it (talking about high speed aircraft designed objects).
The space shuttle is only there cause it's a "space" shuttle cause for example the object looks more like a 60's F4 phantom.
the 11:50 radio controlled miniature version is totally bullshit and proves nothing, you can make any type of wing fly as long as the center of gravity lies in a certain range, by adjusting the horizontal stabilizer. Easy to understand : create a paper plane, and control it's horizontal stability by placing a lest at different distances from its nose until you found the best place. Done. So they copied the design and made it fly ? The only thing it says is that they had the good idea of fin + horizontal stabilizer, not that the design is viable. Not to mention, with a propeller in such a light object (max a few pounds), the object is pulled, and its stability is tremendous. The wings don't even need to have a good lift efficient design, if its all flat it would work, as long as the stabilizer is in control. But if you put the propeller in the back, pushing and not pulling, it would certainly be much more difficult for the crafter of that radio controlled object to make it viable (because the horizontal stabilizer is too close to the wing). It can work, but is far from "perfect" has they say a few second laters. With its tremendous fin it would have good lateral stability, but the stabilizer is stupidly placed. If those ancients knew that well about aerodynamics, they would understand the principle of component arm and arm moment ! And not place a stabilizer so close it's in the wing's downwash or stuff like that.
It's totally possible that ancients had some cool ideas about flying, after all this is said to be the oldest dream of the human kind, but saying they had modern jets given or explained by aliens is just thinking too fast and is total confirmation bias.
I would LOVE to do researches about the subject, but without that bullshit confirmation bias they all have. I would have no problem finding no evidence, because that's how it works, and someone has to do it. But to those people : if your goal is to bring something to science, stop, if your goal is to entertain us in documentaries, go on
EDIT: and big lol at the "Shakuna Vimana". I had forgoten this one, big big joke here
And gosh, I'm only at 1/4 of the video
But the question is not that one. It is :
