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Mokele

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Posts posted by Mokele

  1. I'm bashing the short studies that lead to false reporting or deabtes among scientist do to short studies where is the long and repeated studies that will clear up the false reporting or deabtes .

     

    You don't have the slightest clue how science works, do you?

     

    You want long studies? Look around. Every one of the studies you disparage is long, well done, with adequate controls and rigor.

     

    News flash:Sometimes things are complicated and subtle, and thus take more than one study to figure out. And we can't know how complicated things are without doing studies first.

  2. I wanted to be a paleontologist as a kid, and my love of dinosaurs seems to have been more intense and persistent than normal. I briefly diverted into aerospace during college (for the money), but now I'm back to critters (though living ones).

  3. The small one looks much better now. There's still something not quite right about the big one. It seems as if the legs are just sort of stomping the ground uselessly, causing the body to pivot at the shoulder without any real benefit. The forelimbs/wings also don't move very much.

     

    I think a key issue is how to think of limbs. Imagine a line from the shoulder to the ground contact (foot, hand, toe, whatever). This is the "effective limb", and it functions as an extensible strut. it can do two things, pivot and change length, and all movements are some combination of the two. A walking human uses their legs mostly as a fixed-length strut, pivoting at the hip to produce motion, while a jumping human (from a standing start) uses their legs mostly by extending the "effective leg" without much angle. Running human legs are a mix.

     

    For the large pterosaur launch, consider the back "leg-struts" as mostly extending (via changes in joint angle), while the "wing-struts" stay a mostly fixed length and rotate (the angle of rotation should be large, maybe 80 degrees or so). The back legs push off, and the body "pole-vaults" over the wings. Once it begins to arc downwards (past vertical for the "wing-strut"), the wings flip up and then beat downwards.

  4. I've met the guy who came up with this, actually - he gave a talk on the topic. Unfortunately, the paper is in some obscure journal without much online presence.

     

    Your animations have a few problems, and I'll take them in order.

     

    First, for the small one, it looks like the feet come up, then 'stomp' in order to push off, with not real change in torso height. In actuality, birds taking off crouch low to the ground (how low varies, and it's a very quick movement), then push off their legs as the wing swings up. The feet have completely left the ground before the wing even begins with swing down.

     

    For the big one, the wings/arms aren't moving through a great enough angle when on the ground, giving it a very stiff appearance. It should be one movement, no running start, and it should vault over the forelimbs like a pole vaulter, with a large change in torso height during the movement.

  5. Science, at it's core, is "Oooh, that's neat! I wonder what happens if I poke it with a stick?"

     

    Seriously, for all the high-minded philosophy of science, it can really all be traced back to "poke it with a stick".

  6. so you're saying that two at a time will stretch the tendons to a range where they are less elastic, hence requiring-wasting more energy?

    but why can't it be the opposite? maybe taking it one at a time is way under the contraption range of the tendons(muscles) which will then require more energy for them to shrink up to a level they aren't used to, hence needing more energy?

    while two at a time might fit the medium or usual contraction of the muscles more?

     

    can we say it depends on the type of workout a person one is used to do?

    (put simply, the ratio of yellow to red muscle(types 1 and 2 in wiki) fibers might change from one to another, hence one would find one at a time easier and vice versa)

    note; if my biological informational basis here is inaccurate my cancellation of this factor would be wrong.

     

    yeah, it's pretty much completely inaccurate. The simple one first - muscle fiber type differences may affect the cost between individuals, but within an individual it won't account for any difference between 1 stair vs 2.

     

    Basically, the leg as a whole is a complex system - you have muscles, which attach in complex ways with moment arms that vary with joint position, with force that depends upon length, contraction velocity, and history, with a few springs (tendons) and pressurized compartments (fascia) thrown in. However, if you move it beyond a certain range, or to certain positions, the muscles will be too stretched or too short to generate much force in a particular action, and may be acting against unfavorable lever arms.

     

    Attempting to boil it down to a simple concept, because you're flexing your hip and knee more by going up two stairs, you may be putting your muscles at a serious disadvantage. There will, of course, be variation between humans, mostly due to simple leg length, but on the whole, there will be an "optimum" step that minizimies caloric work, and departures will result in lower muscle efficiency in turning calories into mechanical work.

  7. Just a quick hit-and-run to make sure everyone knows what this ammendment will NOT cover:

     

    NOT covered:

     

    - Abortions for the mother's health (as opposed to life)

     

    - Severe fetal abnormalities, including those invariably lethal shortly after birth

     

    - The mother's mental health, including in cases where the continuation of the pregnancy could lead to self-harm or suicide.

     

     

    Yeah, real compassionate.

  8. I suspect that two at a time will require more energy, because the greater excursion of the limb puts the muscle off the plateau of the length-tension relationship (muscles generate less force if too short or too long). Thus, to generate the same force, more motor units will have to be activated, resulting in greater metabolic cost.

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