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Thread: Arthur C Clarke on giantism

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    Arthur C Clarke on giantism

    In "Profiles of the Future", Arthur C Clarke writes:

    "For the human body is a piece of architecture that has evolved to give its best performance when it is 5 or 6 feet tall. Double its height and it would weigh eight times as much; but the bones which supported it would be increased in area of cross section only four times. The stresses acting upon them would therefore be doubled in intensity; a 12 foot giant is possible, but he would always be breaking his bones and he would have to be careful how he moved. To make a 12 foot version of homo sapiens practical would involve a major redesign, not a straight scaling up.The legs would have to be proportionately much thicker, as the example of the elephant shows. The horse and the elephant both follow the same basic quadripedal design - but compare the relative thickness of their legs! The elephant must be near the sensible limit of size for a land animal."

    Is Clarke correct, in view of the fact that the fossil record shows that x5-x10 larger than today flora and fauna existed in the past: mosses which once grew up to 3 feet tall now reach only 1", cockroaches 12" now 1", shellfish 5 feet across now 8", crocodiles could reach 50 feet in length, today a paltry 12 feet, dragonflies with 4 foot wingspans, now only 4" etc?

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    Many humans weigh twice what they should (too many Mars bars) and their legs don't break all the time. Bones can become stronger by bearing weight, I think.
    Formerly Frog march..............

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    Yes, Clarke is correct. As he says, larger organisms need different proportions from smaller organisms.

    Grant Hutchison

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    Quote Originally Posted by Frog march View Post
    Many humans weigh twice what they should (too many Mars bars) and their legs don't break all the time. Bones can become stronger by bearing weight, I think.
    What these large humans are doing is exploiting the safety margin on which their bones operate - active humans exert transient forces on their skeletons equivalent to several times their body weight, and bones are "designed" to cope with that. Obese humans can operate within that margin most of the time - but you would be astonished the damage they can do to their skeletons with an awkward fall.

    Grant Hutchison

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    Were not the ancient 50' long 8 ton crocodiles a 'straight scaling up' rather than a 'major redesign' of today's 1 ton 12 footers?

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    Crocs are semi-aquatic, and water buoyancy helps somewhat. Even on land, they're built "low" which should also help. They should do better than a scaled-up horse, say.

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    Quote Originally Posted by wd40 View Post
    Were not the ancient 50' long 8 ton crocodiles a 'straight scaling up' rather than a 'major redesign' of today's 1 ton 12 footers?
    They were, using Clarke's potentially misleading terminology, a major redesign. By which he simply means that weight-bearing bones need to scale differently from the overall dimensions of the animal.

    Grant Hutchison

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    Reminder: Clarke, while a brilliant man in many respects, was not a biologist or medical doctor. His statements on anatomy should be taken as those of an educated amateur.
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    Quote Originally Posted by Noclevername View Post
    Reminder: Clarke, while a brilliant man in many respects, was not a biologist or medical doctor. His statements on anatomy should be taken as those of an educated amateur.
    But the square-cube law he invokes here is just mathematics and physics, in which he held a first-class degree - and it's something I was taught as a basic principle while studying medicine.

    Grant Hutchison

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    Quote Originally Posted by grant hutchison View Post
    But the square-cube law he invokes here is just mathematics and physics, in which he held a first-class degree - and it's something I was taught as a basic principle while studying medicine.

    Grant Hutchison
    Yes, the SC law is physics. Describing the human body's adaptations to increased weight is anatomy.

    I'm not saying he's wrong, I'm just saying in general to look for confirmation from sources beyond just his word.
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    As a follower of American/Canadian football, some of these guys are BIG. Alnost two meters and 150 kilograms is not unusual. They seem to pay a price though; many are short lived. Grant might know more.

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    Indricothere didn't seem to be wildly mis-proportioned.

    126bb7ea839f76627ac317dfba189e4d.jpg

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    These giant bugs that once existed seem to be basically scaled-up versions of what we have today ie they are not major redesigns.

    My question is: would it be only a 20'-60' tall version of the species homo sapiens who would require a major redesign?

    Have any truly giant human skeletons >10' ever been found or reported, or are they all hoaxes?

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    Quote Originally Posted by wd40 View Post
    These giant bugs that once existed seem to be basically scaled-up versions of what we have today ie they are not major redesigns.

    My question is: would it be only a 20'-60' tall version of the species homo sapiens who would require a major redesign?

    Have any truly giant human skeletons >10' ever been found or reported, or are they all hoaxes?
    They are hoaxes.
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    BTW, it was Galileo who first described the square-cube law.

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    Quote Originally Posted by wd40 View Post
    These giant bugs that once existed seem to be basically scaled-up versions of what we have today ie they are not major redesigns.
    IIRC it is mainly breathing limitations that keep bugs from growing that big. The air back then had more oxygen to support bug growth. I believe they may have also had proportionately thicker exoskeletons, though I could be wrong.

    Added: ACC was talking about the support properties of bone in the quote above, not that of chitin.
    Last edited by Noclevername; 2017-Feb-23 at 03:41 AM.
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    Something I wrote about the possibility of giant bugs in a film review back in '01:


    So, blow up a horse fly to the size of a horse, and its six spindly legs would snap pretty quickly under its new bulk. Unless, of course, the legs were thickened out of proportion to the rest of its growth. No, to make a fly as big as a horse, you’ve got to redesign it pretty thoroughly (internal skeleton, internal lungs, a heart for circulation, et cetera et cetera), and by then you’ve pretty much got a horse after all. An ugly one, to be sure.

    What then of a house fly as big as a house? It gets worse the bigger you expand it. That's why the gigantic ants of Them, the humongous 'hoppers of The Beginning of the End, the stupendous spider of Tarantula, the deadly mantis of, well, The Deadly Mantis are never brought up when real-world defense spending is on the table.

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    Quote Originally Posted by wd40 View Post
    In "Profiles of the Future", Arthur C Clarke writes:

    "For the human body is a piece of architecture that has evolved to give its best performance when it is 5 or 6 feet tall. Double its height and it would weigh eight times as much; but the bones which supported it would be increased in area of cross section only four times. The stresses acting upon them would therefore be doubled in intensity; a 12 foot giant is possible, but he would always be breaking his bones and he would have to be careful how he moved. To make a 12 foot version of homo sapiens practical would involve a major redesign, not a straight scaling up.The legs would have to be proportionately much thicker, as the example of the elephant shows. The horse and the elephant both follow the same basic quadripedal design - but compare the relative thickness of their legs! The elephant must be near the sensible limit of size for a land animal."

    Is Clarke correct, in view of the fact that the fossil record shows that x5-x10 larger than today flora and fauna existed in the past: mosses which once grew up to 3 feet tall now reach only 1", cockroaches 12" now 1", shellfish 5 feet across now 8", crocodiles could reach 50 feet in length, today a paltry 12 feet, dragonflies with 4 foot wingspans, now only 4" etc?
    The great size of ancient fauna remains a major unsolved mystery - one which I have looked around for an answer to but continually come away unsatisfied. The fossil records indicates some variable in the environment at the time which we do not understand fully. Theories abound, none of them seem correct to me. Personally, I think the answer is tied up in physics and what it ultimately has to say about planetary formation and evolution.

    What I think it shows in the meantime is life's great adaptability - a great variation which has occurred over a very short evolutionary time.

    Not sure where Clarke is coming from in the context of any possible future, but given that size appears to have been bigger in the past, the future trend appears likely to be smaller rather than bigger.

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    Quote Originally Posted by Canis Lupus View Post
    Not sure where Clarke is coming from in the context of any possible future, but given that size appears to have been bigger in the past, the future trend appears likely to be smaller rather than bigger.
    Well, there were also smaller things in the past. Horses, for instance.

    Evolution works in all directions and trends. Any that allow for survival, that is.
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    J.B.S.Haldane wrote "On Being the Right Size" in 1928.

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    Quote Originally Posted by wd40 View Post
    These giant bugs that once existed seem to be basically scaled-up versions of what we have today ie they are not major redesigns.
    You know the paintings accurately reproduce the proportions of the original animal? You have made detailed measurements of their limbs, and of their living relatives / creatures that fill a similar niche? And then made a mathematical comparison?
    Or are you saying they just look kinda like their living relatives?

    Grant Hutchison
    Last edited by grant hutchison; 2017-Feb-23 at 11:48 AM.

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    Quote Originally Posted by Noclevername View Post
    Well, there were also smaller things in the past. Horses, for instance.

    Evolution works in all directions and trends. Any that allow for survival, that is.
    Miniature mastodons on Santa Barbara Island, for instance. Cut off from the mainland they had to get smaller or wipe out their food supply.

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    How stuff works
    Based on this evidence, a newer explanation has emerged for why there were so many huge dinosaurs. It points to the physiology of their bones and lungs, which were similar to those of birds. The largest dinosaur, the long-necked Supersaurus, is thought to have weighed 45 tons, about as much as seven African elephants. They had air pockets in their bones, which lightened their weight and kept them from collapsing as they grew larger. They also had very efficient lungs, so their respiration and heat exchange could better support the larger size. The fact that they laid eggs and could reproduce relatively quickly may have given the bigger animals a reproductive advantage as well [source: Viegas].

    Enormous animals were not only the province of prehistory, though, and the fact that the Supersaurus was a land animal keeps it from being the largest animal ever to live on our planet. In fact, the largest animal we know of lives today. The blue whale makes the 45-ton Supersaurus seem like a weakling. Blue whales are estimated to be 89 to 98 feet long (it's difficult to measure such a huge creature under water) and can weigh up to 150 tons. Their water-logged existence, which increases their buoyancy, makes it possible for them to weigh three times what the Supersaurus weighed without their bodies collapsing [source: Switek].
    National Geographic

    Predatory dragonflies the size of modern seagulls ruled the air 300 million years ago, and it's long been a mystery how these and other bugs grew so huge.

    The leading theory is that ancient bugs got big because they benefited from a surplus of oxygen in Earth's atmosphere. But a new study suggests it's possible to get too much of a good thing: Young insects had to grow larger to avoid oxygen poisoning.

    "We think it's not just because oxygen affects the adults but because oxygen has a bigger effect on larvae," said study co-author Wilco Verberk of Plymouth University in the U.K.

    "So a larval perspective might lead to a better understanding of why these animals existed in the first place, and maybe why they disappeared."
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    Quote Originally Posted by agingjb View Post
    J.B.S.Haldane wrote "On Being the Right Size" in 1928.
    Arthur Clarke corresponded with Haldane, and wrote about that man's work in his essays.

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    Quote Originally Posted by Canis Lupus View Post
    The great size of ancient fauna remains a major unsolved mystery - one which I have looked around for an answer to but continually come away unsatisfied. The fossil records indicates some variable in the environment at the time which we do not understand fully. Theories abound, none of them seem correct to me. Personally, I think the answer is tied up in physics and what it ultimately has to say about planetary formation and evolution.

    What I think it shows in the meantime is life's great adaptability - a great variation which has occurred over a very short evolutionary time.

    Not sure where Clarke is coming from in the context of any possible future, but given that size appears to have been bigger in the past, the future trend appears likely to be smaller rather than bigger.
    I thought the mainstream view was that there was much more oxygen in the air back then.
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    Quote Originally Posted by profloater View Post
    I thought the mainstream view was that there was much more oxygen in the air back then.
    Yeah, and that allowed the tubes that brought air into the interior of the bugs (the tracheal system) to transport more oxygen. There's a rule about the diameter of pipe increasing means greater cross-section ... (Me mathgnostic.)

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    Quote Originally Posted by profloater View Post
    I thought the mainstream view was that there was much more oxygen in the air back then.
    At the time of the dinosaurs, no - there was actually less oxygen for much of their time. At the time of the giant Carboniferous insects, yes.

    Grant Hutchison

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    Quote Originally Posted by wd40 View Post
    Is Clarke correct, in view of the fact that the fossil record shows that x5-x10 larger than today flora and fauna existed in the past: mosses which once grew up to 3 feet tall now reach only 1", cockroaches 12" now 1", shellfish 5 feet across now 8", crocodiles could reach 50 feet in length, today a paltry 12 feet, dragonflies with 4 foot wingspans, now only 4" etc?
    I think the entire idea that ancient organisms were all giants and everything has become smaller is a distortion of reality and a case of selection bias.

    Take for example your note about 'mosses which once grew up to 3 feet tall now reach only 1"'. I'm not exactly sure what plants you are referring to, but I'm going to guess Lepidodendron (commonly, but incorrectly called "Giant club mosses"). These thrived during the Carboniferous and are the basis of a lot of our coal deposits.

    And they got a lot bigger than 3 feet, they were as large in height and diameter as modern trees. And while their modern descendants are tiny, it isn't that plants in general got smaller. The Lepidodendron were replaced, first by conifers, and later by flowering trees, all of which are just as large.

    It has already been mentioned that the largest animal ever is alive today, not some prehistoric animal.

    And while there may have been large insects, there were plenty of small insects in ancients times, many of which are close to indistinguishable from their modern equivalents.

    Before someone claims that there has been a significant shift in size, I'd like to see a more statistically significant study rather than cherry-picking particularly large ancient examples.
    Last edited by Swift; 2017-Feb-23 at 11:30 PM. Reason: typo
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    Fossil coelacanths were about half a meter long. Modern live coelacanths are about 2 meters long.

    https://en.wikipedia.org/wiki/Coelacanth

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    Quote Originally Posted by grant hutchison View Post
    At the time of the dinosaurs, no - there was actually less oxygen for much of their time. At the time of the giant Carboniferous insects, yes.

    Grant Hutchison
    Thanks and yes it was insects that would be able to breath at larger sizes, lunged animals can grow bigger if they can support their weight like whales.
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

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