Ultima Thule

In ancient times the northernmost region of the habitable world - hence, any distant, unknown or mysterious land.

Thursday, August 31, 2006

Could it pick up Raquel? Not in a million years



By Aussiegirl

From the article: The results may even be of interest to film buffs. Prof Neill Alexander, of Leeds University, once calculated that a scene in the film "One Million Years BC", in which Raquel Welch is carted off by the flying reptile, is inaccurate. Even if humans had been alive then, a pterosaur would have been too feeble to lift her, he concluded. However, with his model, Dr Wilkinson can now reconsider this question. "Perhaps Raquel would like to take part in our experiments."
This is the second time that Raquel has appeared in Ultima Thule. The first time was as part of an article on the Casimir effect -- it might be noted, for all my red-blooded male readers, that an attractive photo of her accompanies this first article. Here the earnest professor grapples with the question, Could a pterodactyl have been able to carry her? I found a good illustration for the present article, in which Raquel stands, scantly clad in her best cave-girl outfit, unaware that a pterodactyl is flying towards her, ready to pick her up -- or can he? That's the point of the experiment.

Telegraph | Connected | Could it pick up Raquel? Not in a million years

Could it pick up Raquel? Not in a million years

The mysteries of how the pterodactyl stayed airborne against the odds could be solved by flying a model over the Fens, finds Roger Highfield.

The largest flying creature ever to have lived could soon be swooping around the skies over Cambridge, after an absence of millions of years.

The creatures, the first with backbones to take to the air, ruled the skies during the days of the dinosaurs and died out with them some 65 million years ago. Called the pterosaurs, (or pterodactyls) they came in a huge range of sizes.

There were gull-sized creatures, giants such as Anhanguera ("Old Devil") and Tupuxuara with wing spans of about four metres, and massive flyers like Quetzalcoatlus, with wingspans of more than 10 metres.

Now Dr Matthew Wilkinson, of Cambridge University, with the German model builder Vivian Bock, have finished the most accurate model of Anhanguera ultra ever built to test ideas about how it was able to fly, until this particular species died out about 100 million years ago.

Scientists have argued for years about how these giants could take off and land, given that their size should have made their minimum flight speed dangerously high and hindered their ability to take off to throwing themselves off a cliff face.

Much debate has centred on whether their wings were narrow and bird-like, leaving their hind limbs free, or wide, incorporating the hind limbs, which would have limited their running.

In earlier work, Dr Wilkinson showed how the biggest pterosaurs got into a flap, solving the enduring problem of how these giants could get off the ground if their wings were tethered to the legs - a fourth finger sported a thin membrane connected to the body and the hind legs, akin to the wing of a bat.

With Prof Charles Ellington, of Cambridge, and Dr David Unwin, in Berlin, he found that the secret was a unique bone called the pteroid, which was like a thumb, only it sprouted from the creature's wrist.

The traditional view is that this bone pointed towards the shoulder of the creature, and supported a skin-like forewing in front of the arm.

Thus the forewing, which scientists called the propatagium, was slim, short and ineffectual.

However, exceptionally well-preserved fossils from Brazil of Ahanguera and its relatives indicate that the pteroid could have pointed forwards, giving a much larger forewing with a far greater range of movement, rather like the leading edge flap of a modern aircraft.

The wings "could not be vigorously flapped", Dr Wilkinson said. But having large, relatively moveable forewings meant that they could always catch the air - crucial for take-off - and fits in with the discovery of fossilised footprints of larger species, which suggest that they took off from flat ground.

Dr Wilkinson's results indicate that the biggest might have merely needed to spread their wings while facing into a moderate breeze for lift-off. Wind-tunnel tests of models incorporating the forward pteroids performed much better than the traditional narrow version, showing the creatures were efficient and agile fliers, not just ineffectual gliders.

As a consequence, it was likely that this design feature made it possible for the creatures to grow to such a huge size, Dr Wilkinson said.

Yet not everyone is convinced that a forward-facing pteroid could cope with the stresses of flying, so flying the model pterosaur, will put his theories to the test.

Military and hang-glider enthusiasts were also interested in seeing the robo-pterosaur, which will glide and twist its wings initially as it soars over the fens, but may be able to flap in later versions, he said.

The results may even be of interest to film buffs. Prof Neill Alexander, of Leeds University, once calculated that a scene in the film One Million Years BC, in which Raquel Welch is carted off by the flying reptile, is inaccurate.

Even if humans had been alive then, a pterosaur would have been too feeble to lift her, he concluded. However, with his model, Dr Wilkinson can now reconsider this question. "Perhaps Raquel would like to take part in our experiments."

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