Posted on 03/21/2008 2:01:20 AM PDT by Swordmaker
It is a fairly easy demonstration that nothing any larger than the largest elephants could live in our world today, and that the largest dinosaurs survived ONLY because the nature of the world and of the solar system was then such that they did not experience gravity as we do at all; they'd be crushed by their own weight, collapse in a heap, and suffocate within minutes were they to.
A look at sauropod dinosaurs as we know them today requires that we relegate the brontosaur, once thought to be one of the largest sauropods, to welterweight or at most middleweight status. Fossil finds dating from the 1970's dwarf him. The Avon field Guide to Dinosaurs shows a brachiosaur (larger than a brontosaur), a supersaur, and an ultrasaur juxtaposed, and the ultrasaur dwarfs the others. Christopher McGowan's "DINOSAURS, SPITFIRES, & SEA DRAGONS", Harvard, 1991 cites a 180 ton weight estimate for the ultrasaur (page 118), and (page 104) describes the volume-based methods of estimating dinosaur weights. McGowan is Curator of Vertebrate Paleontology at the Royal Ontario Museum.
This same look requires that dinosaur lifting requirements be compared to human lifting capabilities. One objection which might be raised to this would be that animal muscle tissue was somehow "better" than that of humans. This, however, is known not to be the case; for instance, from Knut Nielson's, "Scaling, Why is Animal size So Important", Cambridge Univ Press, 1984, page 163, we have:
"It appears that the maximum force or stress that can be exerted by any muscle is inherent in the structure of the muscle filaments. The maximum force is roughly 4 to 4 kgf/cm2 cross section of muscle (300 - 400 kN/m2). This force is body-size independent and is the same for mouse and elephant muscle. The reason for this uniformity is that the dimensions of the thick and thin muscle filaments, and also the number of cross-bridges between them are the same. In fact the structure of mouse muscle and elephant muscle is so similar that a microscopist would have difficulty identifying them except for a larger number of mitrochondria in the smaller animal. This uniformity in maximum force holds not only for higher vertebrates, but for many other organisms, including at least some, but not all invertebrates."
Another objection might be that sauropods were aquatic creatures. Nobody believes that anymore; they had no adaptation for aquatic life, their teeth show wear and tear which does not come from eating soft aquatic vegetation, and trackways show them walking on land with no difficulty.
A final objection would be that dinosaurs were somehow more "efficient" than top human athletes, or had better "leverage". Superposed images of sauropods and powerlifters at roughly equal-weight sizes show the sauropod's legs to be puny compared to the human athletes', as one would expect, since the sauropod's body was mostly digestive system, the humans's mostly muscle. The better-leverage argument would require the sauropod to be a spectacularly knob-kneed sort of a creature whose knees and other joints were wider than those of the human athletes, even though the rest of their legs were spindly by contrast with the humans. A quick look at the pictures dispels this.
By "scaled lift", I mean of course a lift record divided by the two-thirds power of the athlete's body weight. As creatures get larger, weight, which is proportional to volume, goes up in proportion to the cube of the increase in dimension. Strength, on the other hand, is known to be roughly proportional to cross section of muscle for any particular limb, and goes up in proportion to the square of the increase in dimension. This is the familiar "square-cube" problem. The normal inverse operator for this is to simply divide by [the] 2/3 power of body weight, and this is indeed the normal scaling factor for all weight lifting events, i.e. it lets us tell if a 200 lb. athlete has actually done a "better" lift than the champion of the 180 lb. group. For athletes roughly between 160 and 220 lbs, i.e. whose bodies are fairly similar, these scaled lift numbers line up very nicely. It is then fairly easily seen that a lift for a scaled up version of one particular athlete can be computed via this formula, since the similarity will be perfect, scaling being the only difference.
Consider the case of Bill Kazmaier, the king of the power lifters in the seventies and eighties. Power lifters are, in the author's estimation, the strongest of all athletes; they concentrate on the three most difficult total-body lifts, i.e. benchpress, squat, and dead-lift. They work out many hours a day and, it is fairly common knowledge, use food to flavor their anabolic steroids with. No animal the same weight as one of these men could be presumed to be as strong. Kazmaier was able to do squats and dead lifts with weights between 1000 and 1100 lb. on a bar, assuming he was fully warmed up.
Any animal has to be able to lift its own weight off the ground, i.e. stand up, with no more difficulty than Kazmaier experiences doing a 1000 lb. squat. Consider, however, what would happen to Mr. Kazmaier, were he to be scaled up to 70,000 lb., the weight commonly given for the brontosaur. Kazmaier's maximum effort at standing, fully warmed up, assuming the 1000 lb. squat, was 1340 lb. (1000 for the bar and 340 for himself). The scaled maximum lift would be a solution to:
1340/340.667 = x/70,000.667 or 47,558 lb..
He'd not be able to lift his weight off the ground!
A sauropod dinosaur had four legs you might say; what happens if Mr. Kazmaier uses arms AND legs at 70,000 lb.. The truth is that the squat uses almost every muscle in the athlete's body very nearly to the limits, but in this case, it doesn't even matter. A near maximum benchpress effort for Mr. Kazmaier would fall around 600 lb.. This merely changes the 1340 to 1940 in the equation above, and the answer comes out as 68,853. Even using all muscles, some more than once, the strongest man who we know anything about would not be able to lift his own weight off the ground at 70,000 lb.!
Moreover, Kazmaier is using glutteal and lower back muscles in the squat, and pectorals in the benchpress, i.e. extra muscle groups which the sauropod he is being compared to would not be assisted by in standing. Any tiny advantage in leverage which a sauropod might have over the human lifter for any reason, would be overwhelmed by the huge edge in available musculature and the usage of the extra muscle groups on the part of the human in the comparison.
To believe then, that a brontosaur could stand at 70,000 lb., one has to believe that a creature whose weight was largely gut and the vast digestive mechanism involved in processing huge amounts of low-value foodstuffs, was somehow stronger than a creature its size which was almost entirely muscle, and that far better trained and conditioned than would ever be found amongst grazing animals. That is not only ludicrous in the case of the brontosaur, but the calculations only get worse when you begin trying to scale upwards to the supersaur and ultrasaur at their sizes.
How heavy can an animal still get to be in our world, then? How heavy would Mr. Kazmaier be at the point at which the square-cube problem made it as difficult for him just to stand up as it is for him to do 1000 lb. squats at his present size of 340 lb.? The answer is simply the solution to:
1340/340.667 = x/x.667
or just under 21,000 lb.. In reality, elephants do not appear to get quite to that point. McGowan (DINOSAURS, SPITFIRES, & SEA DRAGONS, p. 97) claims that a Toronto Zoo specimen was the largest in North America at 14,300 lb., and Smithsonian personnel once informed the author that the gigantic bush elephant specimen which appears at their Museum of Natural History weighed around 8 tons.
Again, in all cases, we are comparing the absolute max effort for a human weight lifter to lift and hold something for two seconds versus the sauropod's requirement to move around and walk all day long with scaled weight greater than these weights involved in the maximum, one-shot, two-second effort. That just can't happen.
A second category of evidence for attenuated felt effect of gravity in antediluvian times arises from the study of sauropod dinosaurs' necks. Scientists who study sauropod dinosaurs are now claiming that they held their heads low, because they could not have gotten blood to their brains had they held them high. McGowan (again, DINOSAURS, SPITFIRES, & SEA DRAGONS) goes into this in detail (pages 101 - 120). He mentions the fact that a giraffe's blood pressure, at 200 - 300 mm Hg, far higher than that of any other animal, would probably rupture the vascular system of any other animal, and is maintained by thick arterial walls and by a very tight skin which apparently acts like a jet pilot's pressure suit. A giraffe's head might reach to 20'. How a sauropod might have gotten blood to its brain at 50' or 60' is the real question.
Two articles which mention this problem appeared in the 12/91 issue of Natural History. In "Sauropods and Gravity", Harvey B. Lillywhite of Univ. Fla., Gainesville, notes:
"...in a Barosaurus with its head held high, the heart had to work against a gravitational pressure of about 590 mm of mercury (Hg). In order for the heart to eject blood into the arteries of the neck, its pressure must exceed that of the blood pushing against the opposite side of the outflow valve. Moreover, some additional pressure would have been needed to overcome the resistance of smaller vessels within the head for blood flow to meet the requirements for brain and facial tissues. Therefore, hearts of Barosaurus must have generated pressures at least six times greater than those of humans and three to four times greater than those of giraffes."
In the same issue of Natural History, Peter Dodson ("Lifestyles of the Huge and Famous"), mentions that:
"Brachiosaurus was built like a giraffe and may have fed like one. But most sauropods were built quite differently. At the base of the neck, a sauropod's vertebral spines unlike those of a giraffe, were weak and low and did not provide leverage for the muscles required to elevate the head in a high position. Furthermore, the blood pressure required to pump blood up to the brain, thirty or more feet in the air, would have placed extraordinary demands on the heart (see opposite page) [Lillywhite's article] and would seemingly have placed the animal at severe risk of a stroke, an aneurysm, or some other circulatory disaster. If sauropods fed with the neck extended just a little above heart level, say from ground level up to fifteen feet, the blood pressure required would have been far more reasonable."
Dodson is neglecting what appears to be a dilemma in the case of the brachiosaur, but there are at least two far greater dilemmas here. One is that the good leaves were, in all likelihood, above the 20' mark; holding his head out at 20', an ultrasaur would, in all likelihood, starve.
Moreover, it turns out that a problem every bit as bad or worse than the blood pressure problem would arise, perceived gravity being what it is now, were sauropods to hold their heads out just above horizontally as Dodson and others are suggesting. Try holding your arm out horizontally for more than a minute or two, and then imagine your arm being 40' long and 30,000 lb......
An ultrasaur or seismosaur with a neck 40' - 60' long and weighing 25000 - 40000 lb., would be looking at 400,000 to nearly a million foot pounds of torque were one of them to try to hold his neck out horizontally. That's crazy. You don't hang a 30,000 lb load 40' off into space even if it is made out of wood and structural materials, much less flesh and blood. No building inspector in America could be bribed sufficiently to let you build such a thing.
In fact, a cursory look at an Elephant's skeleton
reveals a structural system much like Roman archicture with one and only one purpose in mind, i.e. bearing the elephant's great weight. The legs are columns and the spine is a Roman arch. 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. That doesn't leave much.
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. or so. Modern birds of prey (the Argentinean teratorn) weighing 170 -200 lb. with wingspans of 30' also flew; within recorded history, central Asians have been trying to breed hunting eagles for size and strength, and have not gotten them beyond 25 lb. or thereabouts. At that point they are able to take off only with the greatest difficulty. Something was vastly different in the pre-flood world.
Nothing much larger than 30 lb. or so flies anymore, and those creatures, albatrosses and a few of the largest condors and eagles, are marginal. 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. pterosaur which scientists used to believe to be the largest creature which ever flew:
"Pteranodon had lost its teeth, tail and some flight musculature, and its rear legs had become spindly. 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. Barnum Brown of the American Museum reported an armbone fragment of an unknown species of pterosaur from the Upper Cretaceous of Texas in which 'the culmination of the pterosaur... the acme of light construction' was achieved. 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. of flight muscles as efficient as those in humming birds. But it had reduced its musculature to about 8 lb., so it is inconceivable that Pteranodon could have taken off actively.
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. With a weight of only 40 lb. the wing loading was only I lb. per square foot. 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. per square foot. 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. Cherrie Bramwell of Reading University has calculated that it could remain aloft at only 15 m.p.h. So takeoff would have been relatively easy. All Pteranodon needed was a breeze of 15 m.p.h. when it would face the wind, stretch its wings and be lifted into the air like a piece of paper. No effort at all would have been required. 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. It seems strange that an animal that had gone to such great lengths to reduce its weight to a minimum should have evolved an elongated bony crest on its skull."
Desmond has mentioned some of the problems which even the pteranodon faced at fifty lb. or so; no possibility of flapping the wings for instance. The giant teratorn finds of Argentina were not known when the book was written... they came out in the eighties in issues of Science Magazine and other places.
The terotorn was a 160 - 200 lb eagle with a 27' wingspan, a modern bird whose existence involved flapping wings, aerial maneuver etc. How so? 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.
There is one other problem. Desmond notes a fairly reasonably modus operandi for the pteranodon, i.e. that it had a throat pouch like a pelican, has been found with fish fossils indicating a pelican-like existence, soaring over the waves and snapping up fish without landing. 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. But high places safe from flooding were always there; oceans were always there and fish were always there. The pteranodon's way of life should have been impervious to all mishap; the notion that pteranodon died out when the felt effect of gravity on earth changed after the flood is the only good explanation.
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. With each increase in size, and therefore also weight, a flying animal needs a concomitant increase in power (to beat the wings in a flapper and to hold and maneuver them in a glider), but power is supplied by muscles which themselves add still more weight to the structure.-- The larger a flyer becomes the disproportionately weightier it grows by the addition of its own power supply. There comes a point when the weight is just too great to permit the machine to remain airborne. Calculations bearing on size and power suggested that the maximum weight that a flying vertebrate can attain is about 50 lb.: Pteranodon and its slightly larger but lesser known Jordanian ally Titanopteryx were therefore thought to be the largest flying animals."
Notice that the calculations mentioned say about 50 lb. is max for either a flier or a glider, and that experience from our present world absolutely coincides with this and, in fact, don't go quite that high; the biggest flying creatures which we actually see are albatrosses, geese etc. at around 30 - 35 lb.. Similarly, my calculations say that about 20000 lb. would be the largest theoretically possible land animal in our present world, and Jumbo the stuffed elephant which I've mentioned, the largest known land animal from our present world, was around 16000.
"But in 1972 the first of a spectacular series of finds suggested that we must drastically rethink our ideas on the maximum size permissible in flying - vertebrates. 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 ancient entombing sediments are thought to have been made instead by floodplain silting. 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; as flappers, the Texas pterosaurs would have needed very tall stilt-like legs to raise the body enough to allow the 24-foot wings to clear the ground The main objection, however, still rests in the lack of adequate musculature for such an operation. 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. Dinosaur carcasses imply the presence of dinosaurs. 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. Only continued research will provide the answers."
Note that Desmond mentions a number of ancillary problems, any of which would throw doubt on the pterosaur's ability to exist as mentioned, and neglects the biggest question of all: the calculations which say 50 lb. are max have not been shown to be in error; we have simply discovered larger creatures. Much larger. This is what is called a dilemma.
Then I come to what Robert T. 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 were attacked by aeronautical engineers who simply could not believe that the big Bend dragon had a wingspan of forty feet or more. Such dimensions broke all the rules of flight engineering; a creature that large would have broken its arm bones if it tried to fly... Under this hail of disbelief, Langston and his crew backed off somewhat. Since the complete wing bones hadn't been discovered, it was possible to reconstruct the Big Bend Pterodactyl [pterosaur] with wings much shorter than fifty feet."
The original reconstruction had put wingspan for the pterosaur at over 60'. Bakker goes on to say that he believes the pterosaurs really were that big and that they simply flew despite our not comprehending how, i.e. that the problem is ours. He does not give a solution as to what we're looking at the wrong way.
So much for the idea of anything RE-EVOLVING into the sizes of the flying creatures of the antedeluvian world. What about the possibility of man BREEDING something like a teratorn? Could man actively breed even a 50 lb. eagle?
David Bruce's "Bird of Jove", Ballentine Books, 1971, describes the adventures of Sam Barnes, one of England's top falconers at the time, who actually brought a Berkut eagle out of Kirghiz country to his home in Pwllheli, Wales. Berkuts are the biggest eagles, and Atlanta, the particular eagle which Barnes brought back, at 26 lb. in flying trim, is believed to be as large as they ever get. These, as Khan Chalsan explained to Barnes, have been bred specifically for size and ferocity for many centuries. They are the most prized of all possessions amongst nomads, and are the imperial hunting bird of the turko-mongol peoples.
The eagle Barnes brought back had a disease for which no cure was available in Kirghiz, and was near to death then, otherwise there would have been no question of his having her. Chalsan explained that a Berkut of Atlanta's size would normally be worth more than a dozen of the most beautiful women in his country.
The killing powers of a big eagle are out of proportion to its size. Berkuts are normally flown at wolves, deer, and other large prey. Barnes witnessed Atlanta killing a deer in Kirghiz, and Chalsan told him of her killing a black wolf a season earlier. Mongols and other nomads raise sheep and goats, and obviously have no love for wolves. A wolf might be little more than a day at the office for Atlanta with her 11" talons, however, a wolf is a major-league deal for an average sized Berkut at 15 - 20 lb.. Chalsan explained that wolves occasionally win these battles, and that he had once seen a wolf kill three of the birds before the fourth killed him. Quite obviously, there would be an advantage to having the birds be bigger, i.e. to having the average berkut be 25 lb., and a big one be 40 or 50.
It has never been done, however, despite all of the efforts since the days of Chengis Khan. We have Chengis Khan's famous "What is best in life..." quote, and the typical Mongol reply from one of his captains involved falconry. They regarded it as important. Chengis Khan, Oktai, Kuyuk, Hulagu, Batui, Monke, Kubilai et. al. were all into this sport big time, they all wanted these birds big, since they flew them at everything from wolves and deer (a big berkut like Atlanta can drive its talons in around a wolf's spine and snap it) to leopards and tigers, and there was no lack of funds for the breeding program involved. Chengis Khan did not suffer from poverty.
Moreover, the breeding of berkuts has continued apace from that day to this, including a 200 year stretch during which those people ruled almost all of the world which you'd care to own at the time, and they never got them any bigger than 25 lb. or so.
Remember Desmond's words regarding the difficulty which increasingly larger birds will experience getting airborne from flat ground? Atlanta was powerful enough in flight, but she was not easily able to take off from flat ground. Barnes noted one instance in which a town crank attacked Atlanta with a cane and the great bird had to frantically run until it found a sand dune from which to launch herself. This could mean disaster in the wild. A bird of prey will often come to ground with prey, and if she can't take off from flat ground to avoid trouble once in awhile... it would only take once. Khan Chalsan had explained the necessity of having the birds in captivity for certain periods, and nesting wild at other times. A bird bigger than Atlanta would not survive the other times.
One variety of teratorn, however, judging from pictures which have appeared in the December 1980 issue of "Bioscience" magazine, was very nearly a scaled-up golden eagle weighing 170 lb. or so, with a wingspan of 25' as compared to Atlanta's 10. In our world, that can't happen.
Yes it is... but the loading is more consistent with birds that flap their wings to maintain flight... not with the birds that share body morphology with the Teratorn... the soaring birds.
Now put an engine on that wing... one that can keep it flying. One of the other scientific papers I linked on this discussion reported that the energy necessary to keep the Argentavis flying as a soarer, not even as a flapper, was about 600 Watts - but the Teratorn was only capable of producing 130 Watts - and that calculation was based on using a wing loading similar to a modern Condor of about 7 Kg/M2 not the 11.5Kg/M2.
As for not flapping for take off, there is a technical term for birds who have to wait for wind to take off... Lunch.
I’m going to ask again: there are many extinct bird species; do you have any evidence that average or typical wing loading has changed since the age of the dinosaurs? Have you even bothered to consider the question? If not, why not?
I have considered it... and the evidence is that the morphology of the Teratorn is essentially identical with a modern Condor... but scaled up without the necessary physiological changes in musculature and skeleton to support the additional weight.
By the way, the Argentavis magnificens lived and flew and died to extinction a little over six million years ago... nowhere near the time of the dinosaurs. But there is evidence that gravity may have been even more attenuated when dinosaurs roamed the earth...
Take, for example, the Hatzegopteryx thambema, the largest known species of Pterosaur with a wing span that reached 12 - 15 meters (40 - 50 feet). It's skull was nine meters long... Estimated mass was 400 - 500Kg. (880 - 1100 Lbs) with a wing load of 9.1 Kg/M2.
It was larger than the Quetzalcoatlus Northropi, with its 8 - 10 meter wingspan, whose mounted skeleton is pictured here:
Any problems getting airborne the Argentavis magnificens would have these creatures would have ... in spades.
They are not found with aquatic fossils, but rather with coniferous forest fossils. They are not adapted for water... their foot bones are definitely those of land walkers, not mire plodders.
Wing flapping is nice, but it isn’t the only way of getting airborne, particularly in a region with strong prevailing winds.
You have the same approach to reality as all kooks and conspiracy theorists. Any lack of information about history supports theory X, which requires abandonment of all conventional knowledge.
It’s in line with those who can’t imagine how pyramids or Stonehenge could be built with muscle power; therefore they must have been built with alien technology.
You could do some actual research on the engineering requirements, or you could sit on your ass and assert that you are smarter than all the physicists and cosmologists who have ever lived.
Your claims boil down to which propositions are most reasonable and likely:
1. You are smarter that Einstein and Newton and Kelvin. Vast changes in the rotation rate of the earth over short periods of time have no consequenses except to allow for the existence of one or two large animals. No kinetic energy accounting needed.
2. You have made an elementary error in estimating the weight of a complex animal from a bone fragment, and an elementary error in assuming that a bird with standard wing loading is impossible because it couldn’t leap into the air from a standstill.
3. You are correct in ignoring the fact that no class of animal in the fossil record shows evidence of adaptation to varying gravity. Tens of thousands of complete fossils can be ignored because you have one or two magic bone fragments.
You have returned to ad hominem attacks and misrepresentations of what I wrote.
I really can’t help it if you present yourself as an idiot.
Life size animatronic models have been built of some of the larger dinos, particularly the ones we have complete skeletons of. If you have something to say about structural impossibilities, I suggest you build a model and test your engineering hypotheses.
My own experience leads me to think that living creatures are stronger and more agile than animatronics. In any case, it would be fairly easy to test your hypothesis about maximum neck length.
http://www.youtube.com/watch?v=m_9GnP-lhaY
Some of the smaller ones are obviously costumes worn by people, but the principle remains the same: if you want to demonstrate that a structure is impossible, build one.
So i am insane, a kook, a conspiracy theorist, and now an idiot. How far do you intend to extend you ad hominem attacks?
You claim I made errors on the weights of megafauna. You can find those quoted weights in any text book or reference book on dinosaurs. In fact, except for the original article that started this thread, I have posted only references from recognized experts in their sciences taken from peer reviewed scientific journals. Weights when presented were also extracted from recognized resources in paleontology and are the accepted weights for the animals to which they refer.
Your idea that “lifesize animatronic models” of some of the dinosaurs could be used to “test” whether they could move is absurd. Those models are merely a synthetic skin over a metal frame with some hydraulic actuators which have no relationship to the real thing made of dense muscle, skin, tendons, and bone that weighs many times more than the model.
You continue to ignore the well established Square Cube LAW (where is that reference to it only applying to “idealized spheres?” I’m still waiting for that ) and now you want us to believe a basically air filled model with steel or aluminum bones, hydraulic “muscles,” and steel cable “sinews and tendons” is the same as the real thing for determining whether a flesh and blood animal muscle could lift a mass of muscle and bone at the end of a very long lever. Who’s the idiot here? It’s not me.
Evidence for the difference in weight? Or is discussing actual numbers beneath your dignity?
My comments on your credibility are restrained. I have at least suggested putting my skepticism to the test with engineering mock-ups.
You did point out an error that I made, the posting of a mis-labelled skeleton picture. I agreed that it was probably mis-labelled and thanked you for finding the error. I am still not certain that the picture which I have found in several articles on the internet about Teratorns is not what it claims to be, a Teratorn. But I have agreed with you on this thread until I can find an answer to what it is. You have not offered the same courtesy to me when I have pointed out errors that you have made.
You have demanded that I answer questions, which I have. On the other hand, you have ignored every question I have posed to you. Again you do not extend to me the same courtesy I have extended to you.
Now for your straw-man arguments that you posted:
Your claims boil down to which propositions are most reasonable and likely:
1. You are smarter that Einstein and Newton and Kelvin. Vast changes in the rotation rate of the earth over short periods of time have no consequenses except to allow for the existence of one or two large animals. No kinetic energy accounting needed.
Where have I claimed to be smarter than Einstein, Newton, and Kelvin?
And I told you I did not subscribe to that theory. Don't you read what I post? The person who posted that hypothesis did indeed account for the kinetic energy... he said it tossed the moon into orbit. Whether it balanced or not, I can't say. Ask him.
2. You have made an elementary error in estimating the weight of a complex animal from a bone fragment, and an elementary error in assuming that a bird with standard wing loading is impossible because it couldn’t leap into the air from a standstill.
I have made an error? These extrapolations of the beasts involved were done by experts in paleontology and are the accepted weights. A few have been challenged (which I pointed out) but they are mostly well within the "ballpark" of the weights ALL paleontologists claim for megafauna.
Loons and Albatrosses, birds with large wings with loadings around 9 Kg/M2 compared to the much heavier and relatively weaker Teratorn's 11.5 Kg/M2, do indeed get into the air by talking running starts, but they do so in areas where they have no natural predators... and over water... and have a much lower minimum glide rates. The Teratorn's lived in a time and area where Thylacosmilus (a marsupial Sabre-tooth predator), Saber-toothed cats, and Bear-dogs hunted... all primary predators capable of taking a grounded Teratorn down and eating it if it could not get into the air quickly enough.
By the way, you claimed the Teratorn's 11.5 Kg/M2 wing loading is in the middle of modern bird wing loading... and therefore not a problem. Not true. The much smaller and lighter Wandering Albatross, Diomedea Exolans, has a wing loading of ~9Kg and a maximum wing span of about 10 feet. Another one of those inconvenient to your position scientific papers, this one from Stanford University states:
"The wing loading of albatrosses is very high also. Indeed, it is thought that albatrosses are close to the structural limits of wing length and wing loading."
How does that fit with your unsupported claim? How does that fit with a 170 lb bird with a 28 foot wingspan and an 11.5 Kg/m2 wing load? Do you perhaps think that it would be beyond the "structural limits of wing length and wing loading?"
I also provided you with a peer reviewed scientific article written by a paleontologist, an aeronautical engineer, and an ornithologist, published in the Proceedings of the American Academy of Science, which included the information that the Teratorn would have required a 39 mph (60 feet per second) glide rate and to launch itself into flight would have to fall from a 65 foot height to acquire his glide rate (at which he would still drop ~2 feet for every second of glide). So did this bird have to "leap" 65 feet into the air so it could fall to gain its flight speed? Or did leaping into the air only work with constant 39 mph prevailing winds? As an alternative launching technique, the article also proposed that the bird would have to run for about 100 yards in an attempt to attain a 30 mph speed (~45 feet per second) to take off into a convenient 10 mph headwind on a 10% downslope... right. sure. The world record 100 yard dash for a human, an animal that is evolved for running as a biped, is 9.4 seconds and the athlete who made that record was running at an average of ~31 feet per second. Yet these scientists propose that the Argentavis magnificens was running 50% faster than a champion human athlete into a 10mph head wind merely to achieve his minimum glide rate to take off into the air? Don't these guys look at the implications of what their conclusions mean?
I think, that based on this evidence, it is a proper conclusion that a bird of the size of the Teratorn would have distinct multiple flight problems relating to its weight... problems that would dissipate if you adjust gravity downward.
3. You are correct in ignoring the fact that no class of animal in the fossil record shows evidence of adaptation to varying gravity. Tens of thousands of complete fossils can be ignored because you have one or two magic bone fragments.
I am ignoring your "fact" because it isn't a fact. It's an assertion you are making absent proof or evidence.
You fail to see the evidence in front of your face that a four foot wingspan dragonfly IS proof of a fossil showing varying gravity because it has no adaptation for larger muscles and increased wing area over its much smaller modern descendent to support the greater weight IF it lived in a 1G environment. There are thousands of fossils in the record that defy modern expectations of both animal and plant sizes and growth. Again you make claims without providing proof. Every mega-animal that weighs more than the 30,000 or so pounds that seems to be the maximum weight for modern land animals is also proof that SOMETHING was different about conditions that allowed the 66,000 pound Diplodocuses to survive... or the almost complete fossil of the Seismosaurus Hallorum, on display at the New Mexico Museum of Natural History & Science, that is estimated to have weighed in at 160,000 to 200,000 lbs., 5 to 6 times MORE than the theoretical limit of the mass that modern muscles can lift. And YOU continue to claim that these weights are not right.
So, JS1138, how much DID the Diplodocus and the Seismosaurus weigh? Produce a figure... and back it up with your reasons for why your figure is right and every text book on Dinosaurs is wrong.
You stated early on that you are ". . . not expert enough to comment on the square cube problem. . ." and then you proceeded to criticize my use of it and challenge the law's validity and mis-applied it to unlike shapes with your Chesthut Sparrow to California Condor comparison in a mis-guided reductio ad absurdum argument whose rebuttal you completely ignored... and then you start to make ex-cathedra statements about the Square Cube Law as though you ARE an expert... designed to designed to denigrate my use of it and imply to other readers that it can not and should not be universally applied.
By the way, JS, where is that link that proves your claim that the Square Cube Law only applies to "...spheres and polyhedrons that can be mathematically approximated by spheres..." I await your links... confident that you cannot provide them because it's a "square" "cube" law... not a "sphere" "polyhedron" law...
Almost 100 posts ago, I told you that I chose NOT to post any more calculations for you. In response to Shryke's request, against my better judgement that it would be a waste of my time, I went ahead and started posting the requested calculations. I expected you to respond exactly as you have done; you ignored what I posted, ignored the authoritative sources, and threw more spit wads. You also escalated the ad hominem attacks. As I told you before, that is the last refuge of the debater who has no facts or arguments.
Your one and only link to a source that you claimed was from a "real scientist" was easily refuted... and when I did, you also ignored that.
Quite frankly, JS1138, while the discussion has been interesting, since you have chosen to imply that I am insane, a kook, a conspiracy theorist, and an idiot, I have grown tired of YOU. I have decided you are a waste of my time. I will no longer respond to your posts on this thread.
To all of the rest of you, agree or diagree with the premise, I will respond and continue the discussion and/or debate.
Thanks Swordmaker.
You make the fundamental error made by all crank scientists. You assume that a few bits and pieces of unexplained phenomena or unknown history can be assembled into evidence for overturning mainstream science. In your particular case, you argue that the existence of a bird whose wing loading is near the theoretical limit for its type could not have existed unless gravity was weaker.
Your evidence for this is the presumed existence of predators.
You have neglected to include evidence for any wide ranging or systematic adaptations for changes in gravity over time. Dramatic changes in gravity would affect every living thing above a few grams in mass. It would affect the size an structure of plants; it would affect all birds and insects. We have excellent remains of all classes of plants, insects and birds covering the last 60 million years, and there is no evidence for adaptations for changing gravity.
You have a few bone fragments for large dinosaurs. Their reconstruction could lead in a number of directions, but you have chosen a reconstruction that leads to maximum difficulty.
But the signature assumption of a crank scientist is the assumption that major physical constants can change, or that large changes in the orbit or rotation of planets can change without catastrophic heating effects.
Excellent rebuttal. I didn’t know the thread was still continuing. I’ll have to read through it later.
It was and is fun... until JS1138 started making it personal with ad hominem. I put up with it far beyond the point of irritation attacks. Look at my posts. You will find jokes and humor. JS1138 was not discussing... he was baiting and not responding to any points made. Look at the previous post... again he attributes to ME the weights given to the megafauna by mainstream scientists as though I was making up the data. He really does not know what he is talking about. I am still waiting for his proof of ANYTHING... specifically the Square Cube Law only applies to idealized sphere nonsense. Discussion is not a one way street. JS1138 made it a waste of my time.
Thanks. Let me know what you think.
Please describe your square cube law relating to the rod if it were 2 feet long, and 3 feet long, with the same thickness.
Thank you for saying that! Real science is subject to experimental verification. I have no quarrel with the philosophizing on this thread, but the misstatements of easily disprovable "fact" drive me nutty.
Your yahoo ‘voted upon’ solution is wrong. The weight of an object at sea level is the same at the equator as a pole because the seas form an equi-potential surface. The water corrects for variations in gravitational and centrifugal accelerations.
Yes, that was the point I was suggesting. And I think that a higher percentage of oxygen in the atmosphere would also facilitate larger life forms in species other than insects, by providing more efficient respiration and thus more energy to overcome the weight of their larger size.
It also occurs to me that the percentage of oxygen in the atmosphere may have been significantly reduced by the massive fires caused the impact about 65 million years ago.
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