LostInThought7
Registered Senior Member
I may be remembering incorrectly, but wasn't the scrap of text talking about the ancient mass destructive weapons, the text referenced earlier...wasn't it found to be a hoax? A forgery?
Lynn White, Jr., the unassumingly great historian of medieval technology (1907-1987), mentions in a monograph written in 1961 probably the first person to attempt flight -- a Muslim who lived in Andalus (Islamic Spain) in the middle of the 9th century A.D. by the name of Ibn Firnas.
According to a Moroccan historian al-Maqqari (writing some 750 years later), White reports, Ibn Firnas “covered himself with feathers for the purpose, attached a couple of wings to his body, and, getting on an eminence, flung himself down into the air, when, according to the testimony of several trustworthy writers who witnessed the performance, he flew a considerable distance, as if he had been a bird, but, in alighting again on the place whence he had started, his back was very much hurt, for not knowing that birds when they alight come down upon their tails, he forgot to provide himself one.”
Let it go. There were no planes in India or Egypt or anywhere. If there were planes then there should have been some solid evidence except the pictures on the wall.
Sounds like a fairy tale to me. A hang glider has about 150 sq ft to allow a person to not drop like a rock and basically be held aloft by upslope winds. So if we were to convert this to 3 foot wide wings this would mean that we would need a wing span of 50 ft. What possible material could be used in a ancient time to construct this. How could somebody possible maneuver (or even hold them up) something of that size and weight. So he took off flew around and landed with no tail and fifty foot wings.
You believe that story?:shrug:
Surely a person can hang-glide for a while after jumping off a high cliff, especially if the winds are right. That sounds like what Ibn Firnas did.
i hope this is a joke.. the models are pretty solid evidence.. when blown up to scale actually fly very far
Well, if we want to be charitable, in older days precise observation and reporting was prioritized way below a good story, so what might have happened is that he jumped off a cliff and managed enough lift to not get himself killed, as most trying that stunt have.Sounds like a fairy tale to me. A hang glider has about 150 sq ft to allow a person to not drop like a rock and basically be held aloft by upslope winds. So if we were to convert this to 3 foot wide wings this would mean that we would need a wing span of 50 ft. What possible material could be used in a ancient time to construct this. How could somebody possible maneuver (or even hold them up) something of that size and weight. So he took off flew around and landed with no tail and fifty foot wings.
You believe that story?:shrug:
That's ridiculous. You can't take a device that uses an airfoil for flotation and "blow it up" proportionally and expect it to float.i hope this is a joke.. the models are pretty solid evidence.. when blown up to scale actually fly very far
That's ridiculous. You can't take a device that uses an airfoil for flotation and "blow it up" proportionally and expect it to float.
The mass of an object dictates how much force is needed to lift it, and mass is proportional to the cube of linear dimension. The surface area of the airfoil dictates how much force is available to lift it, and surface area is only proportional to the square of linear dimension.
So if you take any arbitrary flying object and expand it proportionally by, say, doubling its linear dimensions, you end up with an enlarged version that has eight times the original mass. However, the airfoils will only have four times their original area. The linear dimensions of the airfoils must be expanded by an additional 41.4% before they can provide the force necessary to support the mass.
If you multiply linear dimension by 10, you increase the weight by a factor of 1000, so you need to increase the linear dimensions of the wings by the square root of 1000, which is about 32.
This is why the largest birds like the 300lb/135kg ostrich can't fly. It would need something like a 90ft/27m wingspan. Even to glide on thermals it would need a significant fraction of that.
So anyone who claims that he "blew up" a tiny toy flying machine and got it to fly is just telling a tall tale.
Either you didn't read what Fraggle wrote, or you didn't understand it. Either way you are wrong. (To see why read and understand Fraggle's last post.), if what you have is a scale model, and you blow it back up to full size, presumably it can fly, if the original could.
India is expected by most of the gurues to be ahead of China by 2025..
Hahahaaaa.. A country with 18 ( eighteen ) official languages .. No infrastructure.. Squillions of religions.. Millions of children begging daily on the streets..
This is all going to change in 25 years ??..
Yeah right ( Tui Ad ).. )
Either you didn't read what Fraggle wrote, or you didn't understand it. Either way you are wrong. (To see why read and understand Fraggle's last post.)
Okay. But that wasn't how I read it. I thought they were flying toys, not non-flying scale models of workable vehicles.Actually, I don't think sifreak21 quite knows what he is talking about, but to be fair, if what you have is a scale model, and you blow it back up to full size, presumably it can fly, if the original could.
So the model needs to be launched at approximately the same speed as the full-size prototype? Wow!Anyway, the problem is more complex than this, because speed is an important factor in creating lift, and speed doesn't scale. If you make a 100th scale model of a medium-sized jet liner, you get a model that is 45cm in wing-span and weighs 8kg. This will fly if you can launch it at some 300 knots! (160kts if you fitted flaps and slats.)
No, he's right. He is postulating that the Indians built a full size flying machine that actually worked. It has not survived, and all that has been passed down to us are small scale models. As he explained, these cannot fly. It's just the opposite of my scenario: the small one flies because it was designed to, but the blown-up model does not.Either you didn't read what Fraggle wrote, or you didn't understand it.
The point is, you've got three scenarios:It is not possible for both to fly.
- The large one can fly but the small one cannot.
- The small one can fly but the large one cannot.
- Neither one can fly.