Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site imsvax.UUCP Path: utzoo!linus!decvax!genrad!panda!talcott!harvard!seismo!umcp-cs!cvl!elsie!imsvax!ted From: ted@imsvax.UUCP (Ted Holden) Newsgroups: net.origins Subject: more on dinosaurs and load-bearing Message-ID: <391@imsvax.UUCP> Date: Sat, 7-Sep-85 14:12:38 EDT Article-I.D.: imsvax.391 Posted: Sat Sep 7 14:12:38 1985 Date-Received: Tue, 10-Sep-85 08:57:26 EDT Organization: IMS Inc, Rockville MD Lines: 106 There are two articles on the net now having to do with the capacity of the really heavy sauropod dinosaurs to bear weight, one by myself and another by Stanley Friesen. Some comments: Mike Huybenzs writes: >Ted, your calculations and observations include a number of fundamental >errors. >First, extrapolation of human strength to heavy-bodied quadruped dinosaurs >does not take into account the fact that the mechanical advantages of the >differently proportioned limbs are quite different. Differing muscle >attachment points would give the dinosaurs' muscles much greater leverage, >perhaps several times more. >Your observations from imaginative drawings in books are also wildly >inaccurate: your "ten foot diameter" legs should be measured in the upper >thigh, which in most modern quadrupeds is well above the belly. I'm >sure you would also disprove horses and elephants by their small leg >cross-section below the belly. In addition, quadrupods seldom have a >circular thigh cross section, else they would bulge in the way you claim >the ultrasaur should. >As others have mentioned, please check original research literature, rather >than popular books. That's where the science is: popular books are usually >pale reflections, drained of details and facts that won't sell to >scientific illiterates. The objection that any animals thigh is wider than its calf or ankle is irrelevant; a ten foot wide animal with ten foot wide THIGHS is impossible. The objection that no animal's thighs are perfectly round is also irrelevant. The starting point for the entire calculation was weight and CIRCUMFERENCE of thigh; If you insist that the ultrasaur's thigh was only 8 feet from side to side, I will just as logically insist that it was then necessarily 12 or 13 feet from back to front, still impossible on an animal whose body was 25 or 30 feet long and 10 feet wide. The notion that the dinosaurs thighs were more efficient than Kazmier's is simply wrong by a very wide margin. The thigh muscles in the human would be pulling fairly straight, while the outer layers of muscle in the disproportionately much wider thigh of the sauropod would not only be pulling at a vector angle, they would be pulling THROUGH the inner layers of muscle i.e. the different layers of muscle in such a wide limb would get in eachother's way. Try thinking these things through logically, Mike, instead of making up or looking up "facts". Your mind, if properly used, is a better reference than many textbooks. I mean, the Lord designed your mind; the guy who wrote that textbook you're quoting from, like as not, was someone as ill informed as you. As to the notion that revealed truth and TRUE KNOWLEDGE can only be found in Academia, don't go away, Mike; that's coming up in a few paragraphs. The comparison between human weightlifters and the ultrasaur is admittedly crude, but it is hard to get any kind of a real handle on something like that. I believe that if you make the ballpark figures good ones, and then set the whole thing up so that EVERYTHING favors the sauropod, even to the point of being ridiculous, and then show that he still couldn't make it, then the whole thing is basically valid. I further believe that I DID that. There are several points I didn't even bother to mention because I thought they would occur to anyone who thought about it. These are: 1. The HUMAN leg being the more efficient, as demonstrated. 2. The fact that I was comparing what the human could lift when fully warmed up to the load the sauropod must face when getting up after a nap, totally cold. 3. The fact that I was comparing what the human could SQUAT to the load the sauropod must lift OFF THE GROUND. 4. The fact that the constant K itself would not be as high for the sauropod as for the maximally trained human athlete. If we were to be brutally honest and assume that each of these factors were in something like a 1.5 to one ratio, then each would add a factor of (1.5)**.5 to the width of the dinosaur's thigh, which would then be 22 feet wide. Like I say, rather than throw all of this at the good readers on the net, I went with the case in which ALL assumptions favored the sauropod, and he still never made it. I am not going to quote Mr. Friesen's article here; it is on the net. Basically, he claims that a Mr. R.M. Alexander has computed "load factors", based on the stress that BONES can take, and determined thereby that dinosaurs could function normally in our world. Is there a problem with that? Anyone who has watched houses being built knows how much weight an ordinary 2x4 can bear when stood end on end. Bones are like that in a way. Take my own humble middle-aged body as an example. I am about 6' 4", 207 lbs, somewhat stronger than the general run of my fellow middle-aged businessmen, but I am no powerlifter. I have friends who are; they are a whole lot stronger than I. Nonetheless, if I kept my back and legs straight, and two of these friends were kind enough to put a bar with five or six hundred pounds on it on my shoulders, I could stand with it; the bones would not break. Mr. Alexander would no doubt then conclude that I could function quite well at 700 or 800 lbs (my 200 plus the bar). I've been out of academia for a number of years now. It could very well be that this kind of thing is now called "SCHOLARLY RESEARCH" at UCLA these days; I don't know. Out here in the real world where I live, however, this is called "LYING WITH FIGURES".