Uncommon Descent Serving The Intelligent Design Community

Of Dragonflies, Spitfires and Elliptical Wings

Share
Facebook
Twitter
LinkedIn
Flipboard
Print
Email

The Dragonfly is a marvel of nature, rated to be one of the all time most effective predators. Similarly, the Spitfire was a breakthrough, fighter-interceptor in the skies over Britain, just under eighty-three years ago. And, oddly, both share a common design feature, elliptical wings:

This is of course an interesting convergence of natural and human technologies. Though, the advantages are with the Dragonfly, a natural helicopter.

The Spitfire’s wings:

(More details, here.)

U/D, Mar 23: Note the clipped wings and radial engine of the Hawker Sea Fury (many later Spitfires also had clipped wings):

Notice, the P-47:

also, the MiG 15, showing where onward technological evolution would go:

The Dragonfly:

It’s worth noting on the Pterostigma, a counterweight often seen as a dark block towards the tip of the leading edge:

The action has been summarised by Norberg:

The pterostigma of insect wings usually is a pigmented spot close to the leading edge far out on the wing, having a greater mass than an equally large wing piece in adjacent wing regions . . . A wing having its mass axis behind its torsion axis is very susceptible to self-excited coupled flapping and feathering vibrations, making gliding flight above a critical speed impossible. Due to unfavourable, inertial, wing pitching tendencies, a still lower speed limit is set to active flight. Due to its mass contribution and favourable location, the pterostigma tends to raise these speed limits by causing favourable, inertial, pitching moments during the acceleration phases of wing flapping . . . The function of the pterostigma of raising the critical gliding speed, at which self-excited vibrations set in, was demonstrated in dragonflies. Although contributing only 0.1 % (one pterostigma) of the total dragonfly weight, it raised the critical speed by 10–25% in one species.

The beauty and subtlety of design! END

Comments
KF,
Dragonflies have a high power/weight ratio, and have been documented accelerating at 4 G linearly and 9 G in sharp turns while pursuing prey
Thanks for these very interesting details. Yes, a dragonfly is an engineering marvel. Not to mention, that it creates copies of itself :)))) God is laughing in Darwinists' faces. When you read all these flight parameters, Darwinists can't look more stupid ... what rational educated person, living in 21st century, with some technical background, can even consider that these species weren't engineered but evolved by some mythical natural process where is no foresight :)))))) And who makes these beyond-absurd claims ? Biologists -- natural science graduates -- who can't support their extraordinary absurd claims with a single scientific proof :))))))) This is very close to what the Flat Earthers believe in ... - - PS: The wings are powered directly, unlike most families of insects, with the flight muscles attached to the wing bases. yeah ... common ancestry confirmed again :))))martin_r
March 25, 2023
March
03
Mar
25
25
2023
08:03 AM
8
08
03
AM
PDT
F/N: Wikipedia's confessions on dragonfly flight:
Dragonflies are powerful and agile fliers, capable of migrating across the sea, moving in any direction, and changing direction suddenly. In flight, the adult dragonfly can propel itself in six directions: upward, downward, forward, backward, to left and to right.[61] They have four different styles of flight.[62] Counter-stroking, with forewings beating 180° out of phase with the hindwings, is used for hovering and slow flight. This style is efficient and generates a large amount of lift. Phased-stroking, with the hindwings beating 90° ahead of the forewings, is used for fast flight. This style creates more thrust, but less lift than counter-stroking Synchronised-stroking, with forewings and hindwings beating together, is used when changing direction rapidly, as it maximises thrust Gliding, with the wings held out, is used in three situations: free gliding, for a few seconds in between bursts of powered flight; gliding in the updraft at the crest of a hill, effectively hovering by falling at the same speed as the updraft; and in certain dragonflies such as darters, when "in cop" with a male, the female sometimes simply glides while the male pulls the pair along by beating his wings.[62] The wings are powered directly, unlike most families of insects, with the flight muscles attached to the wing bases. Dragonflies have a high power/weight ratio, and have been documented accelerating at 4 G linearly and 9 G in sharp turns while pursuing prey.[62] Dragonflies generate lift in at least four ways at different times, including classical lift like an aircraft wing; supercritical lift with the wing above the critical angle, generating high lift and using very short strokes to avoid stalling; and creating and shedding vortices. Some families appear to use special mechanisms, as for example the Libellulidae which take off rapidly, their wings beginning pointed far forward and twisted almost vertically. Dragonfly wings behave highly dynamically during flight, flexing and twisting during each beat. Among the variables are wing curvature, length and speed of stroke, angle of attack, forward/back position of wing, and phase relative to the other wings.[62] Flight speed Old and unreliable claims are made that dragonflies such as the southern giant darner can fly up to 97 km/h (60 mph).[63] However, the greatest reliable flight speed records are for other types of insects.[64] In general, large dragonflies like the hawkers have a maximum speed of 36–54 km/h [--> 10 - 15 m/s] (22–34 mph) with average cruising speed of about 16 km/h [--> 4.4 m/s] (9.9 mph).[65] Dragonflies can travel at 100 body-lengths per second in forward flight, and three lengths per second backwards.[25]
Pretty impressive performance. KF PS, detailed studykairosfocus
March 24, 2023
March
03
Mar
24
24
2023
02:37 PM
2
02
37
PM
PDT
CD @40 of course, we don't know as much as you do ...martin_r
March 24, 2023
March
03
Mar
24
24
2023
09:57 AM
9
09
57
AM
PDT
Martin r/ Of course you do……chuckdarwin
March 24, 2023
March
03
Mar
24
24
2023
09:53 AM
9
09
53
AM
PDT
KF
Similarly, in macrostructures such as wings, focal to this thread, we find many signs of careful, even subtle — pterostigmata, alulae, slotted airfoils, power systems, control systems, weight saving strength structures and more. To take such signs seriously is quite reasonable, especially when, where we can directly test, they are highly reliable, on trillions of cases. So, reversing the projection through cognitive dissonance principles, we see imposition of a denial of evidence because of a dominant and too often domineering ideology of evolutionary materialistic scientism. KF
excellent! You should write a book ... not Dawkins ... you ...martin_r
March 24, 2023
March
03
Mar
24
24
2023
06:24 AM
6
06
24
AM
PDT
CHUCK,
Perhaps, unlike the ID crowd, Dawkins is capable of admitting that there are things he doesn’t know…….
unlike Dawkins, we do know ....martin_r
March 24, 2023
March
03
Mar
24
24
2023
06:18 AM
6
06
18
AM
PDT
M_r, that annoying hum. Rotors, propellers, wings are closely related, as are turbine blades. KFkairosfocus
March 24, 2023
March
03
Mar
24
24
2023
06:00 AM
6
06
00
AM
PDT
CD. the admission is there and undermines the framework. As to your contempt for the ID "crowd," it is obvious to all but those determined not to acknowledge, that many things show strong signs of design. Among them, text of objections such as you made. That is, there is a base of knowledge of signs and what they signify. The next step is, to observe something that today's new magisterium wishes to suppress, key well known signs of design appear in the natural world. Cells have complex, algorithmic, coded information in D/RNA, for example. Likewise, we see fine tuning of the physics of the cosmos that fits it to support C-chem, aqueous medium, cell based life. Similarly, in macrostructures such as wings, focal to this thread, we find many signs of careful, even subtle -- pterostigmata, alulae, slotted airfoils, power systems, control systems, weight saving strength structures and more. To take such signs seriously is quite reasonable, especially when, where we can directly test, they are highly reliable, on trillions of cases. So, reversing the projection through cognitive dissonance principles, we see imposition of a denial of evidence because of a dominant and too often domineering ideology of evolutionary materialistic scientism. KFkairosfocus
March 24, 2023
March
03
Mar
24
24
2023
05:53 AM
5
05
53
AM
PDT
KF I figured you couldn’t resist taking a swing at Dawkins. Perhaps his “confession” was not so inadvertent. Perhaps, unlike the ID crowd, Dawkins is capable of admitting that there are things he doesn’t know…….chuckdarwin
March 24, 2023
March
03
Mar
24
24
2023
05:33 AM
5
05
33
AM
PDT
KF,
... gliding membrane as a sort of “net” while the flight stroke evolved ...
one quick remark regarding the flight stroke "evolution". Darwinists always choose vertebrates or mammals to illustrate the evolution of powered flight. Because it is easier to trick lay public - it seems very plausible. The just-so story goes: when you flap your forelimbs fast enough and the right way, and if there is a gliding membrane, one day you will evolve a true flight. I won't comment on this stupid idea, because it is beyond absurd. But notice, that they never choose for this illustration an insect. I would like to see, how an insect may have evolved wing flapping at 800 times per second (some mosquitos do) These are not wings but rotors.martin_r
March 24, 2023
March
03
Mar
24
24
2023
04:40 AM
4
04
40
AM
PDT
PS, then, we have: https://arstechnica.com/science/2022/07/ready-for-takeoff-imaging-pterosaur-tissue-to-see-how-they-launched/
A group of researchers has recently made an astounding discovery. Using an innovative imaging technique, an international team of scientists has uncovered remarkable details of a pterosaur's soft tissue. Despite an age of approximately 145–163 million years, the wing membrane and the webbing between both feet managed to survive fossilization. Armed with new data, the team used modeling to determine that this little pterosaur had the capacity to launch itself from the water. Their findings are published in Scientific Reports. Fine details Pterosaurs—an extinct type of winged reptile—were the first known vertebrates to take to the air and fly. Their sizes ranged from the very tiny (a wingspan of 25 centimeters) to the absolutely enormous (a breathtaking 10- to 11-meter wingspan). According to the lead researcher on the new work, Dr. Michael Pittman, the small aurorazhdarchid that was studied could have fit in the palm of your hand. Of 12 well-preserved pterosaurs from the Solnhofen Lagoon in Germany, it was the only one with preserved soft tissues. Dr. Pittman is a paleobiologist and assistant professor at the Chinese University of Hong Kong, and co-author Dr. Thomas G. Kaye is with the Foundation for Scientific Advancement. The authors noted that this pterosaur is now among only six known pterosaurs with evidence of webbed feet and approximately 30 with wing membranes. "We are constantly amazed by just how stunning the preserved details can be," Dr. Pittman told Ars, "which keeps getting better and better as we refine the technique more and more." . . . . The preserved wing membrane, as seen through LSF, also offered rare evidence of what Dr. Habib describes as a kind of fiber, called "actinofibrils," running through the wing. Dr. Pittman described the fiber as “a very important support structure that we find in the wings and foot webbing of pterosaurs.” The presence of actinofibrils offered important insight into an aspect of flying that anything—from birds to bats, airplanes, and pterosaurs—risks at certain speeds: aeroelastic flutter. This phenomenon refers to the vibrations a wing will undergo at high angles of attack or at high speeds. A very limited amount of flutter, Dr. Habib said, is OK. But when it reaches the point of extreme vibration—aeroelastic flutter—it’s almost like a flag flapping wildly in the wind. It’s unsafe. “What we’ve been able to deduce from multiple wings that have soft-tissues preserved in the fossil record is that they’re doing two primary things in order to keep the wing from fluttering,” Dr. Habib said. “One of them is active control.” He explained that pterosaur wings contain a lot of muscle, and that muscle can contract to prevent the wing from vibrating. “But,” he continued, “they also have passive stiffening of the wing.” That stiffening is done through a “highly keratinized” wing surface, but also from the presence of actinofibrils. “When the wing starts to automatically curve and starts to stretch, and it’s going to flutter, those actinofibrils will go taut.” Despite all of these new details, it’s difficult to know how all the features were used by the pterosaurs. Dr. Manafzadeh feels that the paper could have gone even further in that direction. “I think they make a pretty convincing case for the capabilities,” Dr. Manafzadeh said, “but it’s less clear whether the animal actually did it. If you really wanted to test whether the animal did it in life, that would require other lines of evidence that aren’t in the paper.” For example, further studies could investigate the "sizes of muscle scars on the bones, [as they] might tell you how much force the muscle generated in life and in what directions," she said. But the authors maintain that their "prior work on pterosaur locomotion has included measurements of bone properties that provide direct information of real in-life loads, similar to what is suggested." "Given that pterosaurs are extinct," the researchers said, "we can’t really say anything more than what they were capable of. But data like muscle scar shape and size would provide additional support.”
H'mm, pterostigma are truly an elegant solution.kairosfocus
March 24, 2023
March
03
Mar
24
24
2023
02:29 AM
2
02
29
AM
PDT
M_r, let's try, bats -- membrane wing flyers: https://ucmp.berkeley.edu/vertebrates/flight/bats.html
The Chiroptera, or bats, are the second most diverse group of mammals, and are the only mammals ever to evolve true powered flight. The evolutionary origin of chiropterans is still somewhat of a mystery, because the fossil record of bats is scant. [--> as usual] Some cladistic analyses indicate that bats are most closely related to the dermopterans, such as Cynocephalus, the colugo or "flying lemur" (which does not fly and is not a lemur). But others suggest that they are not so closely related. However, their ancestors may have been similar in some ecological respects. Phylogenetic and functional data suggest the inference that the hypothetical ancestor would have been nocturnal, insectivorous, arboreal, and a glider. The earliest known bats appear in the Eocene epoch, and had long tails and other primitive flight adaptations [--> pod and boom design is primitive? Tell uncle AH-64 that!], but were generally similar to modern bats in most ways. We can infer [--> yup] that bats gradually evolved true flight from a gliding arboreal ancestor, possibly using the gliding membrane as a sort of "net" while the flight stroke evolved. [--> oversimplification] The bat wing (shown above) is made of a membrane supported by the arm and the greatly elongated fingers of the hand, which support the distal part of the wing (where thrust is produced). Bats have such flight adaptations as echolocation (in microchiropterans), keen senses, modified pectoral girdle (at right), reduced radius, large humerus and ulna, clawed fingers, high metabolic rate, and a uropatagium: a membrane stretched between the hindlimbs that helps to stabilize the bat during flight, and often to capture prey with. This is thought to have originally been a gliding adaptation, as most gliders incorporate their hindlimbs into their gliding airfoil. A new bone, the calcar [--> common design, but with mods, as in body plans again], supports the membrane from the heel (roughly analogous to the pteroid bone in pterosaur forelimbs). As you may know if you've ever watched bats hunting insects on a cool summer night, many bats are adept and agile flyers, with marvelous adaptations provided by their ancestry and 60-odd million years of history. [--> notice ideological subtext]
Let's add for pterosaurs: https://ucmp.berkeley.edu/vertebrates/flight/pter.html
The first vertebrates to evolve true flight were the pterosaurs, flying archosaurian reptiles. After the discovery of pterosaur fossils in the 18th century, it was thought that pterosaurs were a failed experiment in flight, or that they were simply gliders, too weak to fly. More recent studies, including work done by UC Berkeley's Dr. Kevin Padian, have revealed that pterosaurs were definitely proficient flyers, and were no evolutionary failure; as a group they lasted about 140 million years (about as long as birds have)! Pterosaurs are thought to be derived from a bipedal, cursorial (running) archosaur [--> in short, speculation on body plan origin] similar to Scleromochlus in the late Triassic period (about 225 million years ago). Other phylogenetic hypotheses have been proposed, but not in the context of flight origins. The early history of pterosaurs is not yet fully understood because of their poor fossil record in the Triassic period. [--> sudden appearance, as usual] We can infer that the origin of flight in pterosaurs fits the "ground up" evolutionary scenario, supported by the fact that pterosaurs had no evident arboreal adaptations. Some researchers have proposed that the first pterosaurs were bipedal or quadrupedal arboreal gliders, but these hypotheses do not incorporate a robust phylogenetic and functional basis. The issue is not yet closed.
And:
The pterosaur wing (shown above) was supported by an elongated fourth digit (imagine having a "pinky finger" several feet long, and using that to fly!). Pterosaurs had other morphological adaptations for flight, such as a keeled sternum (at left) for the attachment of flight muscles, a short and stout humerus (the first arm bone), and hollow but strong limb and skull bones. Pterosaurs also had modified epidermal structures that were wing-supporting fibers, and others that possibly formed hairlike structures to provide insulation. Bird feathers are analogous to the wing fibers of pterosaurs, and both are thought to possibly have been evolved originally for the purpose of thermoregulation (which implies, but does not prove, that both pterosaurs and the earliest birds were endothermic). Pterosaurs also had a bone unique to their clade. It is called the pteroid bone, and it pointed from the pterosaur's wrist towards the shoulder, supporting part of the wing membrane. Such a novel structure is rare among vertebrates, and noteworthy; new bones are unusual structures to evolve — evolution usually co-opts bones from old functions and structures to new functions and structures rather than "reinventing the wheel."
Have these theorists ever designed and developed a successful wing? KFkairosfocus
March 24, 2023
March
03
Mar
24
24
2023
02:18 AM
2
02
18
AM
PDT
KF @30 a nice sum up. Like I said earlier, powered flight - such an embarrassment for Darwinists. But this is exactly how it ends, when unqualified people ( biologists ) mess with engineering ... Powered flight did not evolve. PERIOD. Get over it biologists and finally stop brainwashing people with your absurd ideas ...martin_r
March 24, 2023
March
03
Mar
24
24
2023
01:49 AM
1
01
49
AM
PDT
CD, I looked at one of the more enthusiastic reviews, which is inadvertently revealing:
It’s a fun romp, unless you’re a creationist, in which case you should consider avoiding this book. The author has some harsh words for creationists. [--> Ideological agenda, vitiating credibility] He examines how evolution could have [--> just so stories told in the lab coat] prompted insects, then birds and mammals, to take to the air. He compares the slow evolution of animals over millions of years [--> flight is a key example of FSCO/I where for key integrated systems, complexity is manifestly irreducible] to the fast evolution of human technology during the two centuries between the first manned balloon flight to the first manned moon landings. [--> Notice, embedded frameworks] It seems there’s much we don’t know for sure about how early animals flew. We’re imagining [--> money shot, inadvertent confession, just so story confirmed] what a complete 1000-piece jigsaw puzzle looked like from 50 pieces we found at random. Much of the book is conjecture—educated guesses. [--> prezactly] The author kept the book short and non-technical, very easy to read. No math required. [--> flight, ballistics and related thermodynamics are all high intensity mathematics, there is a reason for the reputation of rocket science] If you’ve ever watched birds or bats or flying insects and imagined being one, this book is for you.
On a more sober-minded note, let's excerpt further from https://ucmp.berkeley.edu/vertebrates/flight/evolve.html
A comparative study of the functional morphology of the wings of the earliest known flying members of the lineage with the "pre-wing" structures of likely ancestors and close relatives provides the best evidence for how wings evolved. Why wings (and hence flight) evolved from this point is a matter of contention among scientists; various hypotheses proposed include: 1 Wings evolved from arms used to capture small prey. (This seems rational, so we can ask whether the ancestral forms were actually doing this.) 2 Wings evolved because bipedal animals were leaping into the air; large wings assisted leaping. (This is possible; any amount of wing could assist leaping. Remember that we first need phylogenetic evidence for a bipedal running or leaping origin.) 3 Wings were used as sexual display structures; bigger wings were preferred by potential mates. (This is a non-falsifiable evolutionary hypothesis — we cannot test it.) 4 Wings evolved from gliding ancestors who began to flap their gliding structures in order to produce thrust. (This is reasonable and possible, but only with phylogenetic evidence for an arboreal gliding origin.) It seems that #1, #2, and #4 are the best hypotheses to use for the origin of wings because they can be tested by bringing in other lines of evidence. Move on to consider these origins, but remember: the issues of the evolution of flight and the origins of flight are inextricably linked.
In short, empirically weak speculation, after 160+ years. A successful flying entity is a highly coordinated, functionally organised entity and the pterostigma is an example of the impact of a subtle feature on aerodynamics, mechanical behaviour and performance, up to 25% improvement for 0.04% or 1 in 2500 weight increment, a clear island of function illustration to go with the general advance of elliptical wings. BTW, bird wing slots using flight feathers and the alula are, again, relevant cases. On the former, I note how double slotted flaps on the DHC-6 Twin otter enhance stol flaperon performance. For the alula, Wiki confesses:
The alula /?ælj?l?/, or bastard wing, (plural alulae) is a small projection on the anterior edge of the wing of modern birds and a few non-avian dinosaurs. The word is Latin and means "winglet"; it is the diminutive of ala, meaning "wing". The alula is the freely moving first digit, a bird's "thumb", and typically bears three to five small flight feathers, with the exact number depending on the species. There also are minor covert feathers overlying the flight feathers. Like the larger flight feathers found on the wing's trailing edge, these alula feathers are asymmetrical, with the shaft running closer to anterior edge . . . . In most situations, the alula is held flush against the wing; however, it can be manipulated. When flying at slow speeds or landing, the bird moves its alula slightly upwards and forward, which creates a small slot on the wing's leading edge. This functions in the same way as the slats on the wing of an aircraft, allowing the wing to achieve a higher than normal angle of attack – and thus lift – without resulting in a stall.[1] The tip of the alula forms a tiny vortex, acting similar to a vortex generator, that forces the airflow over the wing to better bind to it.[2] During stretching of the wing down toward the ground, the alula is abducted from the wing and can be clearly viewed. In falcons, the alula is more prominent, and provides a degree of control when the wing is cupped or tucked in a dive/stoop. The Alulae are particularly notable in peregrine falcons.
Compare here the exercise of gluing split peas on to test the importance of flush rivets for Spitfire performance. It showed, yes, vital. And of course, feathers are a marvel of complex integrated system design in and of themselves, far beyond the myth of shredded scales. Wiki again confesses:
Flight feathers (Pennae volatus)[1] are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (/?r?m?d?i?z/), singular remex (/?ri?m?ks/), while those on the tail are called rectrices (/r?k?tra?si?s/), singular rectrix (/?r?ktr?ks/). The primary function of the flight feathers is to aid in the generation of both thrust and lift, thereby enabling flight. The flight feathers of some birds perform additional functions, generally associated with territorial displays, courtship rituals or feeding methods. In some species, these feathers have developed into long showy plumes used in visual courtship displays, while in others they create a sound during display flights. Tiny serrations on the leading edge of their remiges help owls to fly silently (and therefore hunt more successfully), while the extra-stiff rectrices of woodpeckers help them to brace against tree trunks as they hammer on them. Even flightless birds still retain flight feathers, though sometimes in radically modified forms.
Again, subtle features with key performance impacts. Beautiful, subtle, mission critical designs. KFkairosfocus
March 24, 2023
March
03
Mar
24
24
2023
01:14 AM
1
01
14
AM
PDT
M_r, yes the wing, the direct muscle drive, the pod and boom fuselage and even the sensor turret eyes are all highly relevant design features. They contribute to the Dragonfly as it seems the most efficient aerial predator on earth; of course for an ecosystem, it makes sense that an insect eating predator can be afforded as a control on insects. I suspect, too, Trout in slurping down floating insects are highly efficient. KFkairosfocus
March 24, 2023
March
03
Mar
24
24
2023
12:35 AM
12
12
35
AM
PDT
Relatd, I am very aware that the Jumo 004 was axial flow, which was the future; however materials constraints nigh 80 years ago were relevant. The engine life of the German engines was an issue and we are both aware that materials advances have been drivers of engine performance and thus vehicle performance as part of the technological evolution. KFkairosfocus
March 24, 2023
March
03
Mar
24
24
2023
12:29 AM
12
12
29
AM
PDT
KF, don't misunderstand me, sure, all species are also living entities. What I meant was, that dragonfly's body is pure aerial engineering - a machine in that regards ...martin_r
March 23, 2023
March
03
Mar
23
23
2023
10:44 PM
10
10
44
PM
PDT
chuck,
Dawkins has a whole new book out on flight. How timely is that?
you mean a biologist has a new fairy tales book on flight for children under 5 y, right ?martin_r
March 23, 2023
March
03
Mar
23
23
2023
10:40 PM
10
10
40
PM
PDT
KF/18 Dragonflies are exhibiting classic Beheian devolution. Getting smaller and smaller. Pretty soon they will fit in a thimble. By the by, Dawkins has a whole new book out on flight. How timely is that? (https://www.amazon.com/Flights-Fancy-Richard-Dawkins/dp/1838937854/ref=asc_df_1838937854/?tag=hyprod-20&linkCode=df0&hvadid=533430521017&hvpos=&hvnetw=g&hvrand=16507438538202252406&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1016173&hvtargid=pla-1252127771277&psc=1)chuckdarwin
March 23, 2023
March
03
Mar
23
23
2023
05:22 PM
5
05
22
PM
PDT
Kf at 23, You speak without a comprehensive background. The German Jumo jet engine was axial as opposed to Whittle's centrifugal type. The German engine was superior. They knew which materials were needed, but these materials were not available in quantity. The Jumo engine on the Me 262 had an average run time of 22 hours but could be swapped out quickly. The British did not use their Gloster Meteor in combat against the Me 262.relatd
March 23, 2023
March
03
Mar
23
23
2023
12:22 PM
12
12
22
PM
PDT
Related, you speak of 1942 not 1934, date of the elliptical wing. KF PS, it was want of materials that caused the early jet engines to have running lives of 20 - 100 hours, esp. in Germany. It is why Whittle's centrifugal design was an effective approach. Materials advances have been key to advances for jet engines. PPS, this on jets is useful https://www.youtube.com/watch?v=25i0AzTa5rwkairosfocus
March 23, 2023
March
03
Mar
23
23
2023
11:59 AM
11
11
59
AM
PDT
There was no "aircraft evolution." Just a proper assessment of the facts. The designers of aircraft realized that at speeds approaching Mach 1, the air that held the plain aloft could not move out of the way fast enough. This resulted in a phenomenon called buffeting where the air began to detach from the wing, and then briefly reattach. Any attempt to increase speed would mean the loss of the aircraft itself. Control surfaces would become ineffective. The Germans realized that buffeting could be delayed by sweeping the wings back. In the case of the Me 262, an extra control surface was added to improve high speed handling. As far as jet engines were concerned, there were no 'serious materials advances.' Before being placed on or in aircraft, the engines were tested. The heat was measured and suitable materials were selected to handle the operating temperature. These metals were on hand.relatd
March 23, 2023
March
03
Mar
23
23
2023
08:48 AM
8
08
48
AM
PDT
M_r, as a living entity, it goes beyond but uses mechanisms. To a certain limited extent it will be self moved. KFkairosfocus
March 23, 2023
March
03
Mar
23
23
2023
06:12 AM
6
06
12
AM
PDT
KF
So, while the dragonfly is not reducible to a machine ...
why not ?martin_r
March 23, 2023
March
03
Mar
23
23
2023
04:05 AM
4
04
05
AM
PDT
M_r (attn, PM1 et al), I should note on how the pterostigma is "there" for a very mechanical/engineering reason. So, while the dragonfly is not reducible to a machine, its wings and key features of its wings are amenable to a reverse engineering of nature approach. KFkairosfocus
March 23, 2023
March
03
Mar
23
23
2023
03:03 AM
3
03
03
AM
PDT
M_r, obviously the micron or so range works well enough, but other sizes are viable. As to why, I have no clue. Meanwhile Dragonflies used to be up to a little short of 1 m, now they are down to max about 6 inches, most likely about 3 - 4. KFkairosfocus
March 23, 2023
March
03
Mar
23
23
2023
01:49 AM
1
01
49
AM
PDT
KF @16
M-r, cells can be bigger than we think too, i.e. unicellular organisms up to golf ball or marble size, and up to a 10 footer
yes, but it doesn't answer my question about DNA packaging associated problems -- why is e.g. human cell the size as it is ...martin_r
March 23, 2023
March
03
Mar
23
23
2023
01:43 AM
1
01
43
AM
PDT
M-r, cells can be bigger than we think too, i.e. unicellular organisms up to golf ball or marble size, and up to a 10 footer https://largest.org/animals/single-cell-organism/ KFkairosfocus
March 23, 2023
March
03
Mar
23
23
2023
01:38 AM
1
01
38
AM
PDT
KF,
the pterostigma is an example of subtle, fine tuned design features that work with other aspects of a design to gain advantageous performance.
yeah ... I would like to see that Darwinian trial-error process of pterostigma size/wing location evolution :))))))martin_r
March 23, 2023
March
03
Mar
23
23
2023
01:31 AM
1
01
31
AM
PDT
Darwinism is so funny ... get this: Powered flight - a key evolutionary innovation lost 1000 times ... :))))))))) source: The loss of flight ability has occurred thousands of times independently during insect evolution. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3735250/ PS: seriously, what is wrong with Darwinists ?martin_r
March 23, 2023
March
03
Mar
23
23
2023
01:29 AM
1
01
29
AM
PDT
1 2

Leave a Reply