Berkeley CSUA MOTD:Entry 18388
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2025/07/09 [General] UID:1000 Activity:popular
7/9     

2000/6/2 [Computer/Theory] UID:18388 Activity:high
6/1     Dinosaurs and antigravity:
        http://www.bearfabrique.org/sauropods/biganims.html
        \_ it was once "proven" that you would suffocate if you moved
           faster than 20 miles per hour. What a load of crap.
        \_ /.
           \_ It's \. not /. -- bill gates
           \_ Yeah, but read it.  It proves that at one time the earth's
              gravitational pull was much lower.
              \_ No it doesn't.  Read the responses in /. and you'll see
                 refutation of the numbers.
                 \_ Not surprisingly, slashdotters are wrong.  Bad math.
                    \_ I can't find anything on http://slashdot.org searching for
                       dinasour.  However it seems highly unlikely that they
                       would screw up the trivial math.  It is not the math
                       that is problematic but the underlying assumptions.
                        \_ maybe that's because its spelled DINOSAUR!
              \_ Maybe the atmosphere was richer in oxygen such that muscles
                 could grow much stronger and withstand a much higher force-
                 per-unit-area than those in modern animals.  Maybe the winds
                 blew much stronger than nowadays such that a glider could
                 take off easily.  Just some idea.  -- yuen
                 \_ Wind might help the flyers but doesn't help a 70+ ton
                    beast stand up.  I don't know enough anatomy/biology to
                    say anything about your oxygen theory.  Where's a bio-
                    dynamics major when you need one?
2025/07/09 [General] UID:1000 Activity:popular
7/9     

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www.bearfabrique.org/sauropods/biganims.html
A sauropod's neck, however, particularly in the case of the recent ultrasaur and seismosaur finds, weighed several times the weight of a large elephant and, if held outwards horizontally, would actually arch downwards (the wrong way). Reconstructions actually depict them like that, no thought whatever having been taken as to the consequences, either by the scientists or the artists involved. And so, sauropods (in our gravity) couldn't hold their heads up, and they couldn't hold them out either. Antediluvian Flying Creatures A third category of evidence for attenuated felt effect of gravity in antediluvian times arises from studies of creatures which flew in those times, and of creatures which fly now. In the antediluvian world, 350 lb flying creatures soared in skies which no longer permit flying creatures above 30 lb. Modern birds of prey (the Argentinean teratorn) weighing 170 -200 lb. At that point they are able to take off only with the greatest difficulty. Albatrosses in particular are called "gooney birds" by sailors because of the extreme difficulty they experience taking off and landing, their landings being (badly) controlled crashes, and all of this despite long wings made for maximum lift. The felt effect of the force of gravity on earth was much less in remote times, and only this allowed such giant creatures to fly. No flying creature has since RE-EVOLVED into anything like former sizes, and the one or two birds which have retained such sizes have forfeited any thought of flight, their wings becoming vestigial. A book of interest here is Adrian Desmond's "The Hot Blooded Dinosaurs. Desmond has a good deal to say about the pteranodon, the 40 - 50 lb. It was, however, in the actual bones that the greatest reduction of weight was achieved. The wing bones, backbone and hind limbs were tubular, like the supporting struts of an aircraft, which allows for strength yet cuts down on weight. In Pteranodon these bones, although up to an inch in diameter, were no more than cylindrical air spaces bounded by an outer bony casing no thicker than a piece of card. Here, the trend had continued so far that the bone wall of the cylinder was an unbelievable one-fiftieth of an inch thick Inside the tubes bony crosswise struts no thicker than pins helped to strengthen the structure, another innovation in aircraft design anticipated by the Mesozoic pterosaurs. The combination of great size and negligible weight must necessarily have resulted in some fragility. It is easy to imagine that the paper-thin tubular bones supporting the gigantic wings would have made landing dangerous. How could the creature have alighted without shattering all of its bones How could it have taken off in the first place It was obviously unable to flap twelve-foot wings strung between straw-thin tubes. Many larger birds have to achieve a certain speed by running and flapping before they can take off and others have to produce a wing beat speed approaching hovering in order to rise. To achieve hovering with a twenty-three foot wingspread, Pteranodon would have required 220 lb. Pteranodon, then, was not a flapping creature, it had neither the muscles nor the resistance to the resulting stress. Its long, thin albatross-like wings betray it as a glider, the most advanced glider the animal kingdom has produced. This gave it a slower sinking speed than even a man-made glider, where the wings have to sustain a weight of at least 4 lb. The ratio of wing area to total weight in Pteranodon is only surpassed in some of the insects. Pteranodon was constructed as a glider, with the breastbone, shoulder girdle and backbone welded into a box-like rigid fuselage, able to absorb the strain from the giant wings. The low weight combined with an enormous wing span meant that Pteranodon could glide at ultra-low speeds without fear of stalling. Again, if it was forced to land on the sea, it had only to extend its wings to catch the wind in order to raise itself gently out of the water. The terotorn was a 160 - 200 lb eagle with a 27' wingspan, a modern bird whose existence involved flapping wings, aerial maneuver etc. There are a couple of other problems which Desmond does not mention, including the fact that life for a pure glider would be almost impossible in the real world, and that some limited flying ability would be necessary for any aerial creature. Living totally at the mercy of the winds, a creature might never get back home to its nest and children given the first contrary wind. That should indicate that, peculiarly amongst all of the creatures of the earth, the pteranodon should have been practically IMMUNE from the great extinctions of past ages. Velikovsky noted that large animals had the greatest difficulty getting to high ground and other safe havens at the times of floods and the global catastrophes of past ages and were therefore peculiarly susceptible to extinction. Ovid notes (Metamorphoses) that men and animals hid on mountain tops during the deluge, but that most died from lack of food during the hard year following. The pteranodon's way of life should have been impervious to all mishap; Back to Adrian Desmond for more on size as related to pterosaurs now: "It would be a grave understatement to say that, as a flying creature, Pteranodon was large. Indeed, there were sound reasons for believing that it was the largest animal that ever could become airborne. There comes a point when the weight is just too great to permit the machine to remain airborne. Although excavations are still in progress, three seasons' digging - from 1972 to 1974 - by Douglas A. Lawson of the University of California has revealed partial skeletons of three ultra-large pterosaurs in the Big Bend National Park in Brewster County, Texas These skeletons indicate creatures that must have dwarfed even Pteranodon. Lawson found the remains off four wings, a long neck, hind legs and toothless jaws in deposits that were non-marine; The immense size of the Big Bend pterosaurs, which have already become known affectionately in the palaeontological world as '747s' or 'Jumbos', may be gauged by setting one of the Texas upper arm bones alongside that of a Pteranodon: the 'Jumbo' humerus is fully twice the length of Pteranodon's. Lawson's computer estimated wingspan for this living glider is over fifty feet It is no surprise, says Lawson announcing the animal in Science in 1975, that the definitive remains of this creature were found in Texas. Unlike Pteranodon, these creatures were found in rocks that were formed 250 miles inland of the Cretaceous coastline. The lack of even lake deposits in the vicinity militates against these particular pterosaurs having been fishers. Lawson suggests that they were carrion feeders, gorging themselves on the rotting mounds of flesh left after the dismembering of a dinosaur carcass. Perhaps, like vultures and condors, these pterosaurs hung in the air over the corpse waiting their turn. Having alighted on the carcass, their toothless beaks would have restricted them to feeding upon the soft, pulpy internal organs. How they could have taken to the air after gorging themselves is something of a puzzle. Wings of such an extraordinary size could not have been flapped when the animal was grounded. Since the pterosaurs were unable to run in order to launch themselves they must have taken off vertically. Pigeons are only able to takeoff vertically by reclining their bodies and clapping the wings in front of them; Is the only solution to suppose that, with wings fully extended and elevators raised, they were lifted passively off the ground by the wind? If Lawson is correct and the Texas pterosaurs were carrion feeders another problem is envisaged. The ungainly Brobdignagian pterosaurs were vulnerable to attack when grounded, so how did they escape the formidable dinosaurs? Left at the mercy of wind currents, takeoff would have been a chancy business. Lawson's exotic pterosaurs raise some intriguing questions. Bakker has to say about the Texas Pterosaurs ("The Dinosaur heresies", Zebra Books, pp 290-291: "Immediately after their paper came out in Science, Wann Langston and his students w...
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