Revisiting pterosaurs could improve robotic aircraft
If it looks like a duck and it flies like a duck, it must take off like a duck.
Paleontologists have long assumed that this was the case with pterosaurs, but new research shows that the prehistoric winged lizards used a more clever sighting method. They used all four limbs to land, fuel and jump and soar. Instead of pushing with both legs and flapping the wings as most winged animals do.
Since the hind limbs do most of the work of taking off, the leg bones of birds are stronger than the wing bones. Michael Habib, a researcher at the Center for Anatomy and Functional Evolution at the Johns Hopkins University School of Medicine, analyzed bone structure and strength in 12 species of pterosaurs, from a species the size of a bat to an individual with a ten-foot wingspan.
Habib found that all of them had stronger arms than their legs, which ruled out the possibility that their form of takeoff was like that of a bird. "Instead," he said, "the facts suggest that pterosaurs used all four legs in one or two pushes to take off."
In less than a second, the pterosaur released its hind limbs like a spring, rested on the "joints" of its wings, and used them to give a strong push to fling itself into the sky. Habib thinks that aeronautical engineers can learn from his take-off technique. "A robotic vehicle capable of moving on the ground and also flying in the air will be able to take off quickly and in a limited take-off area, if it uses a method similar to that of the pterosaur"
Catherine Schwank
23 תגובות
The article is correct because the Wright brothers even got the idea from watching birds
Noam: You got dirty.
Hugin,
Regarding entropy - the earth is not a closed system, therefore the entropy in it can decrease, as happens all the time.
Of course, this has nothing to do with your confused words about "regressive evolution", small souls, and a terminal trend of entropy.
"The legality of the small, biorhythmic and large cycles" - complete New Age gibberish.
"The scientific Darwinists are actually creationists" - even more nonsense.
For your information, evolution does not intervene in anything, but only scientifically explains what is happening around us. Just complete ignorance, without any shame.
Hugin - go study instead of talking. It's true that it's easier to talk nonsense all day, and to deal with anal matters, but it's much less helpful.
Wikipedia:
The anal phase:
The anal stage (Latin: anus = anus), lasts between the age of two and three, and is also called the anal-urethral period. This stage is characterized by preoccupation with parentheses
And regarding your misconception that evolution has no definite direction, you are probably not the knowledgeable and expert in the legality of the small, bio-rhythmic and large cycles. You are probably one of those who use the word 'evolution' without realizing that nature is monarchical (depending on the centrality of a fertile and fertile cycle) and in fact you choose a 'method' and are identified With science - you finally come out as a rebel against the orderly and masterful nature. You will be found like them: as a creature that imitates a type of creationism (an intervention that disrupts the heart-core of the bearers of the kingdoms of nature) - as a continuation of 'primordial sin' and borrowed... (how strange that the scientific Derwenzis are actually creationists fighting the creationists. .traditional ..ha ha).
Noam,
Yes, I answered you what entropy is and even expanded (and asked) his concepts.
Basically this concept is attributed to thermodynamics as a measure of disorder in the system.
The entropy in solids is less than in liquid..but what happens when solids become liquid (melt)??
The quote adds and says: "The entropy in a closed system never decreases during a thermodynamic process: if it increases, it is a sign that the process is irreversible; if it does not change, it is a sign that the process is reversible - the end of the heat of the universe."
Regarding the second matter: the fact is that after he reacts (shit on my words) you are not able to see. So does it matter which part I am in? Anal, mature and whatever if flies fly on his shit about the nature of the truth / as the 'systematic concealer'?
Hugin,
Evolution has no definite direction, neither for size, nor for development, but only determines that the survivors will be those that are more suitable for given environmental conditions.
Once again you use concepts that you don't understand incorrectly, and you don't even bother to try to understand them - it's a shame.
You did not answer the second question about entropy - but maybe for your honor it is better that way.
I share your concern about the fate of our dear world, and so do most scientists. In fact, the chance to save the world in the long term will come only through science, for example by developing green energy sources, by preserving living environments, etc.
No rescue will come from the floating and delusional New Age people, who chatter non-stop, spewing out words and concepts that they do not understand at all.
And finally, your repeated reference to defecating and everything related to that, is a bit worrying. Are you back to anal age?
Michael:
No one can see after another, that 'you' especially give a shit about the truths.
Noam:
Views?!
Noam, I responded and paused in the draft, I was afraid that my response might be too harsh and deadly, but since Michael provoked me, here's the copy in Huguenot:
"Unfortunately, yes,
There used to be many, many highly developed souls and today (and especially in the last 100 years) there are many, many shadows of tiny souls who have taken enormous control of the world.
We are not developing, this is just a delusional technocratic/virtual illusion of progress. The opposite is true: we are only retreating towards a general collapse.
Since there is no point in comforting you, the reserves are found in the true believers and spiritual people - nature, who are not exposed at all to the extraterrestrial and artificial world.
After all, in relation to the wonderful and mighty nature (for which there is no substitute), the treacherous and obliging man has become nothing more than a troublesome swarm of flies, an insatiable devourer of resources, a terrible exploiter and despises every good part of the spirit of the place (the good land).
I hope you may understand that the part of me that participates with you in the reaction is also borrowed/broken/smashed: and actually forced to connect here outright."
Noam:
Do you expect a serious response from Hogin?
Like the response to which you responded, the response you will receive will be Hogantotic.
Noam and A. Nan-Ner:
I did not respond to the "strength" part of the response because it is a claim whose meaning is unclear.
What "strength" exactly do you mean?
Serious shearing stresses are applied to the wing for a long time (actually all the time) while a compression force acts on the legs most of the time, during takeoffs and landings a shearing force is added and during flight almost no force acts on them.
In fact the comparison is more or less similar to comparing the power of a ballpoint pen to that of a fan.
Hugin,
Where do you see "regressive evolution"?
The size of the "souls" has nothing to do with it
Besides, what does this have to do with entropy? Are you sure you understand this concept?
A. Ben Ner,
It seems to me that your considerations are wrong:
Assuming that the weight of the 747 is the same on the ground and in the air, then this weight is held on the ground by the wheels, and in the air by the wings, therefore their strength is the same.
The same considerations will also apply to a tiny plane.
Yes, but perhaps we also need to take into account the possibility that in 'that' period the atmosphere was different and all today's calculations are not admissible to the relativity of the forces of nature and the geological/geographical/climatic structure and wind flow cycles that prevailed then.
In short, there are many missing elements in the equations that the "acceptable" scientific methods of today are missing.
Besides, it is again proven that this is a regressive evolution according to the little souls who took control of this world..and until terminal entropy (if the same poor trend continues).
A. Ben-Ner:
Many organisms that develop actually grow.
Compare the man of today with the man of yesteryear, the horse of today with the horse of yesteryear.
The dinosaurs also grew until they died out.
These are just examples of how your claim about favoring the little ones is incorrect.
Moreover - the theories about the reasons for the disappearance of the dinosaurs do not involve the disappearance in size and together with the dinosaurs many small creatures also became extinct.
learned gentlemen
Don't forget that the flying dinosaurs were very heavy compared to the birds of our day. Therefore, they needed strong wing bones also to support the flight muscles and not only for the purpose of detection and takeoff.
It seems that natural evolution, like the evolution of computers, cars, clothes and almost everything that evolves, favors the compact and nimble small organism over the heavy and bulky one.
Another example of "big" and "small" flyers.
If you examine a large plane, say a Boeing 747, you will surely find that its wings are stronger than its legs, but if you examine a tiny plane, a Piper for example, you will find that its wings are weaker than its legs.
light:
There is a problem here because in order to express opposition to a certain religious line of thought there is no need to "put it in my mouth".
As one who actually fights here in all manifestations of faith, creating a presentation as if I expressed a religious opinion actually misses the point.
Michael,
You are right, but the comment about striving for constant improvement is also intended for the readers of the site. Just as you respond to all kinds of religious people who oppose evolution even though you know they will not agree with you despite all the rules of logic, so that the reader of the comments will lean on the side of science and not on the side of the fanatics.
light:
You've already read enough of my comments to be clear that I don't think evolution strives for constant improvement.
I was really confused by assuming it was the ancestors of the modern bird and not an independent species.
All the conclusions would be correct if this were the case, but apparently the situation is not.
Michael,
The conclusion does not follow from the facts. If man exterminates the last of the birds, does that mean that their flight is inferior to walking on two legs? If the cheetahs become extinct, does that mean that the fast run is inferior to the slow walk of the cow that reproduces by the millions?
You cannot infer anything about the behavior of an organism from the fact that it is extinct and this behavior does not appear today. Evolution does not strive for constant "improvement", not to mention the fact that pterosaurs are not the ancestors of birds. It is quite possible that the pterosaurs, due to their take-off methods, became extinct for one reason or another and the take-off method was not restored by the birds because their body structure simply does not fit this method.
If all the birds abandoned the pterosaur's take-off method - it is probably inferior compared to the take-off methods used "with their hands" (actually with their wings) today.
I'm sorry, but the fact that pterosaurs' arms are stronger than their legs is not a necessary condition, nor a sufficient condition, to conclude that pterosaurs used all four limbs to take off.
I think the transformers already came up with this method 🙂