It's not that I don't believe the ancients could have had the technology to fly - I just think that if they did, their flying craft would probably be completely different to the aircraft we have today. I have a personal suspicion that more advanced types of aircraft probably exist today, but because they don't rely on scarce fuel resources and would therefore be much cheaper to operate, and would put the big oil producers and aerospace firms out of business, they kept from the masses, and when they are spotted, they are referred to as "UFOs". This is just my own little conspiracy theory. Maybe the ancients used cleaner and more natural technologies for flying too. Maybe they had airships, using non-flammable fuels. Or "magic carpets". Or something that modern scientists haven't even thought up yet!