I guess that ' s an explanation on using alien tech but still being ancient . Let us , for argument ' s sake , assume we do in fact have an alien crafts that crashed or were gained by whatever means you wish , and our engineers have been going over them for decades . Roswell was in 1947 so we can theoretically say we ' ve had at least that long of a time to spend with alien tech . Perhaps the design of the craft itself wouldn ' t be ideal for military use but the propulsion system could be used in anything . But we still use jet tech from the 40 s . Yes , they are crazy powerful and pretty efficient , but still basically from the 1940 s . If ET can get here and back home again , and we had his propulsion system , I refuse to believe we wouldn ' t be 25 hours a day 8 days a week , working on that . I don ' t for a second think our military would sit on something until they had a ' better understanding of it '. To have a propulsion system that can go interstellar without using huge amounts of fuel would be the biggest thing possible to achieve . Just mining materials from other planets or meteors would be financially unsurpassed if we could do it . We could leave the Earth completely alone and get what we needed from dead areas . Earthicans could take over the galaxy or at least take a look at it . Just mounting an attack anywhere on Earth in a matter of seconds . Of course , the fuel material could be impossible for us to produce here , and that would always be the fallback story for a person making up tales of Area 51 firsthand knowledge . The packaging of the product isn ' t what makes me skeptical of all of it . I don ' t think we should have flying saucers , per se , but there hasn ' t been a massive leap forward in anything . You can see where materials were developed over time using conventional means and by pure accident . They can show their work . The average American isn ' t impressive , but our smart people are , and we have good funding for them . Until ET lands at my front door at noon on Tuesday , I will not believe they have ever been here . There may be tales of wackiness that can ' t be explained and spooky lights in the sky , but aliens will always be last on my list of reasons . We may be on the cusp of greatness , but it will be due to us , not them .