i think that most everyone want to believe that extraordinary thing exist and this film show no restraint in try to exploit that to the full . the presentation be very interesting and well present and the graphic be state of the art and but from a scientific point of view it just doesn not work . hydrogen fill fly bladder . they would need to be the size of a mack truck to be useful . and then there the ever present possibility of a catastrophic explosion . i have no problem with fantasy and just do not try to pass it off a fact . some folk will always misunderstand . all in all the film be entertain and but i constantly find myself say oh brother and what a load of . if you want a fake documentary and watch this be spinal tap instead . or at the very least turn the sound off .