by Karl C. Priest September 12, 2010
Insect flight is mind boggling.
This article is an attempt to explain the miracle of insect flight by using the words of scientists (and secular science reporters) themselves. A much more extensive play on this theme is the wonderful work That Their Words May Be Used against Them by Henry M. Morris. I make no claim to being anywhere close to what Dr. Morris did. In fact, this article is constructed entirely differently than Dr. Morris book.
I omitted (using …) the names of those quoted below. Those can be obtained from the citations. I simply do not wish to use this article to embarrass individuals. I have done that elsewhere: Dawkins, Dawkins is Buggy, Buzzing Evolutionists, Evolution is a Lie, Arrest Threat, Helping Evolutionists Get it Right, and to a lesser extent in other articles. The most stinging expose’ of evolutionism is my article BWAH HAH HAH HAAAA! In fact, many of the quotes below would fit nicely in BWAH HAH HAH HAAAA! On a different tact, several examples below would fit perfectly in Thank God for Insects. Evolutionists cannot help but to Tacitly Admit Creation. One of the key scientists involved in flight design based upon insects appears to be a creationist.
Birds certainly have a place in the history of airplane design and scientist will still discover wonderful things about bird design which will be incorporated into better airplane design. Starting about 1990, technology began to advance to the point where scientists could study the diminutive insects. This puts insects on the cutting edge of flight research.
Scientists want to decipher God’s design of insect flight in order to make mico air vehicles (MAV), nano air vehicle (NAV ), or orinthopters (Google those words), for a variety of purposes such as searching in rubble of collapsed buildings, exploring hazardous areas (radioactive or battlefield for example), spying, and delivering weapons.
Now, loosely categorized, are the words of some highly intelligent folks who will not declare the obvious design features of God’s amazing insects.
(Be sure to scroll to the bottom for links to videos showing insects in flight.)
Everyone knew, of course, that insects flap their wings while jumbo jets don’t, but no one could understand what effect this had. The Cambridge mechanical moth revealed circulating vortices of air moving along the upper wing from the body to the tip, like little tornadoes turned sideways, during the wings’ downstroke. These vortices push air downwards behind the trailing wing edge, and so generate lift.
The vortices are produced through a cunning gamble in which the insect places the wing briefly at a steep tilt to the airflow. If prolonged, this makes the flight stall. But if applied only briefly, it generates the helical airflow pattern before stalling kicks in. So this mechanism of flight is known as ‘delayed stall’.
Insects use what…calls 'unsteady high-lift mechanisms' - tricks to generate more lift than you might expect from conventional aerodynamics. One such trick is found in the very tiniest insects, with wingspans of the order of a millimetre or so, to which the air seems much more viscous than it does to us - more like water than air.
The device was created using extremely high-speed flash photography to track the way smoke particles flow over a locust's wings in a wind tunnel - a technique called particle flow velocimetry. This allowed researchers at the University of Oxford to build a computer model of the insect's wing motion. They then built software that mimicked not only this motion, but also how wing surface features, such as structural veins and corrugations, and the wings' deformation as they flap, change aerodynamic performance.
The simulator could be a big step forward for the many teams around the world who are designing robotic insects, mainly for military purposes, though Thomas expects them to have a massive role as toys, too. Building miniature aircraft is of great interest to the armed forces. In the UK, for example, the Ministry of Defence wants to create a device that can fly in front of a convoy and detect explosives on the road ahead. In the US, the Pentagon's research arm DARPA is funding development of a "nano air vehicle" (NAV) for surveillance that it states must weigh no more than 10 grams and have only a 7.5-centimetre wingspan.
"Getting stable hover at the 10-gram size scale with beating wings is an engineering breakthrough, requiring much new understanding and invention," says... a micromechanics and flight researcher at the University of California, Berkeley. "The next step will be to get the flight efficiency up so hover can work for several minutes."
It wasn't until 1981 that…of the University of Southern California hit on a possible reason: his working model of a fly's wings, immersed in oil, showed large vortices were spinning off the leading edge of the wing as it beat (Annual Review of Fluid Mechanics, vol 13, p 329). Within the vortices air is moving at high velocity, and is therefore at low pressure, hinting at a lift-creating mechanism unlike that of conventional aircraft, in which an angled wing travelling forward deflects air downwards, creating an opposing upward force.
In 1996…was a member of…'s team at the University of Cambridge, which identified the mechanism by which bugs created high lift forces - using a model of a hawkmoth. "We found a leading-edge vortex that was stable over the whole of the downstroke."
The nature of the leading-edge vortex is dependent on the size of the wings, their number, the pattern described by the beating wing and the wing structure.
(http://www.newscientist.com/article/mg20327275.600-locust-flight-simulator- helps-robot-insects-evolve.html?DCMP=OTC-rss&nsref=online-news )
According to a new Cornell study, an optimized flapping wing could actually require 27 percent less power than its optimal steady-flight counterpart at small scales.
Did you know that locusts are the long-distance champs of the insect world? They can fly for hundreds of miles. Science News, Live Science and Science Daily reported on work at Oxford to understand the wing design of “nature’s most efficient flyers.” The researchers are finding that the flexibility in the wing is crucial to the efficiency.
…said that until recently it has been impossible to study insect wings in detail because they flap so fast and their shape is so complicated. Now, with wind tunnels and computer models, the problems are becoming tractable.
…and colleagues used high-speed cameras to capture the details of how wings of the locust Schistocerca Gregaria deform as they flap by bending and twisting. (A similar twist with an extended human arm would start with the thumb pointed slightly up at the top of the flap, then the arm would turn so the thumb is parallel to the ground in the middle of the flap and continue down until the thumb is pointed toward the ground at the end of the downstroke.)
Data from the high-resolution flight images allowed the researchers to create a near-perfect mathematical model of how the flexible, twisting wings propel the insect through the air. With the model in hand, …and his team could predict the shapes of the air currents around the flying locusts. Tiny packets of smoke released near a flying locust showed air swirls similar to swirls predicted by the model.
Figuring out the details of how locusts and other insects fly may help researchers design tiny robotic fliers. “There is a growing interest in the exploration of micro air vehicles. Nature’s designs may be useful in creating synthetic ones.”
WING DESIGN and AERODYNAMICS
Perhaps the most elaborate example of an arthropod joint, indeed one of the most complex skeletal structures known, is the wing hinge of insects—the morphological centerpiece of flight behavior. The hinge consists of an interconnected tangle of tiny, hard elements embedded in a thinner, more elastic cuticle of a rubberlike material called resilin, and bordered by the thick side walls of the thorax. In flies, the muscles that actually power the wings are not attached to the hinge. Instead, flight muscles cause small strains within the walls of the thorax, and the hinge amplifies these into large sweeping motions of the wing. Small control muscles attached directly to the hinge enable the insect to alter wing motion during steering maneuvers. Although the material properties of the elements within the hinge are indeed remarkable (resilin is one of the most resilient substances known), it is as much the structural complexity as the material properties that endows the origami- like wing hinge with its astonishing properties.
By controlling the mechanics of the wing hinge, the steering muscles act as a tiny transmission system that can make the wing beat differently from one stroke to the next.
Electrophysiological studies indicate that this is a phase-control system. Most of the fly’s steering muscles are activated once per wingbeat, but the phase at which they’re activated is carefully regulated by the nervous system. This is important, because the stiffness of these muscles changes depending on the phase in which they are activated within the stroke. Even when the steering muscles are not actively contracting under the control of a motor neuron, they’re still being stretched back and forth by other muscles around them. If a muscle is activated by its own motor neuron while it is lengthening, it becomes stiff; if activated while shortening, it’s relatively compliant. The fly uses the steering muscles as phase-controlled springs to alter the way the large strains produced by the power muscles are transformed into wing motion.
"The evidence indicates that flexible wings are producing profoundly different air flows than stiff wings, and those flows appear to be more beneficial for generating lift."
A hawkmoth's wings are controlled by muscles on the insect's body and have no internal muscles of their own. The bulk of the wing is something like fabric stretched back from a stiff leading edge, fabric that is elastic and bends from inertia as the wing accelerates or decelerates through each stroke.
Our results show that the flexible wings are doing a better job of generating lift-favorable momentum than are the stiff wings. They also are inducing airflow with greater overall velocity, which suggests the production of greater force for flight.”
Together with a biologist at the University of Zurich in Switzerland, and a research assistant also at the California Institute of Technology, …determined how common fruit flies use their wings to make 90-degree turns at speeds faster than a blink of the human eye, let alone the swoosh of a swatter.
To turn, a flying creature must generate enough twisting force, or torque, to offset two forces working against it—the inertia of its own body (think forward motion on a bicycle, once you stop pedaling) and the viscous friction of the air, which for small insects is thought to be like syrup.
The research team found that fruit flies make subtle changes in the tilt of their wings relative to the ground and the size of each wing flap to generate the forces that allow them to turn. Flies then create an opposite twisting force with their wings to stop the inertia of the turn, preventing an out of control spin.
This finding, say the researchers, indicates that inertia, and not friction, is the greater force for the fruit fly to overcome in the turn.
Instead, to execute a turn, a fruit fly generates torque to accelerate into the turn and then the fly has to actively counteract the inertia of the turn by producing torque in the opposite direction, bringing the rotation of the body to a halt, according to the scientists. Once the flies have achieved their desired turn angle, they buzz off.
"In some ways it flies like a helicopter. It has to adjust its body orientation in space and does so using subtle changes in wing motion."
How can stall, which is disastrous for an airplane, help to lift an insect? The answer lies in the rate at which the wings flap. Wings do not stall instantly; it takes some time for the lift-generating flow to break down after the angle of attack increases. The initial stage of stall actually briefly increases the lift because of a short-lived flow structure called a leading-edge vortex.
Together wake capture and rotational circulation also help to explain the aerodynamics of flight control how flies steer. Flies are observed to adjust the timing of wing rotation when they turn. In some maneuvers, the wing on the outside of a turn rotates early, producing more lift, and the wing on the inside of a turn rotates late, generating less lift; the net force tilts and turns the fly in the desired direction. The fly has at its disposal an array of sophisticated sensors, including eyes, tiny hind wings that are used as gyroscopes, and a battery of mechanosensory structures on the wings that it can use to precisely tune rotational timing, stroke amplitude and other aspects of wing motion.
The Berkeley researcher noticed that fruit flies adjust wing-flip timing relative to overall stroke timing, but he didn't understand why. The new experiments suggest that the timing change alters the force and direction of the push on the wings, giving the animals exquisite maneuverability, he claims.
The dragonfly Aeschna cyanea can glide for up to 30 seconds without so much as a wingbeat. Yet its wings look nothing like the supposedly ideal streamlined, cambered wing perfected in 1901 by flight pioneers Orville and Wilbur Wright and used ever since by the aviation industry. Instead, the wing surfaces are highly corrugated, with pleats that stiffen them against bending across their span.
They found that the pleats gave the wings much greater lift than they expected in gliding flight, matching and sometimes bettering that of a similarly sized streamlined wing (Bioinspiration and Biomimetics, vol 3, p 26004). This is because air circulates in the cavities between pleats, creating areas of very low drag that aid the lift-generating airflow across the wing.
If mastering flight is your goal, you can't do better than to emulate a dragonfly.
With four wings instead of the standard two and an unusual pitching stroke that allows the bug to hover and even shift into reverse, the slender, elegant insect is a marvel of engineering.
Dragonflies have a very odd stroke. It's an up-and-down stroke instead of a back-and-forth stroke," she said. "Dragonflies are one of the most maneuverable insects, so if they're doing that they're probably doing it for a reason. But what's strange about this is the fact that they're actually pushing down first in the lift.
"An airfoil uses aerodynamic lift to carry its weight. But the dragonfly uses a lot of aerodynamic drag to carry its weight. That is weird, because with airplanes you always think about minimizing drag. You never think about using drag."
"The fluttering of butterflies is not a random, erratic wandering, but results from the mastery of a wide array of aerodynamic mechanisms."
Insects are more agile than aircraft equipped with superfast digital electronic.'
First and foremost among the butterfly's attributes are highly flexible wings which combine with a slightly rotating wingbeat to change the wing's front, called the leading edge, during each upstroke and downstroke.
The result is a flight that may look unsteady to us but in fact is very efficient, because it generates little turbulence.
There are other times, though, when the butterfly deliberately creates a wake.
It uses something called a leading-edge vortex, in which the front of the wing creates a circular turbulence. The insect subtly uses this wash when it hovers, recycling the momentum to give itself lift and thus save energy.
In another stroke, a mechanism called "clap and fling" that has already been previously documented, the butterfly touches its wings together (the clap) and then separates them rapidly (the fling). This produces a brief vortex that gives it a touch more lift.
The red admirals' versatility has left…awe-struck.
"They switch between mechanisms freely, often using completely different mechanisms on successive wing strokes, and are able to choose different aerodynamic mechanisms to suit different flight behaviours," they say.
Most flying insects beat their wings in large strokes - typically flapping in arcs of 145° to 165° at a frequency determined by body size - to generate aerodynamic forces sufficient for flight. But this cannot explain how a heavy insect with a short wing beat, such as a bee, generates enough lift to fly.
…and his colleagues filmed hovering bees at 6000 frames per second, and plotted the unusual pattern of wing beats. The wing sweeps back in a 90˚ arc, then flips over as it returns - an incredible 230 times a second. The team made a robot to scale to measure the forces involved
It is the more exotic forces created as the wing changes direction that dominate. Additional vortices are produced by the rotation of the wing. "It's like a propeller, where the blade is rotating too," he says. Also, the wing flaps back into its own wake, which leads to higher forces than flapping in still air. Lastly, there is another peculiar force known as "added-mass force" which peaks at the ends of each stroke and is related to acceleration as the wings' direction changes.
The scientists analyzed pictures from hours of filming bees and mimicked the movements using robots with sensors for measuring forces.
Turns out bee flight mechanisms are more exotic than thought.
"The honeybees have a rapid wing beat,"…told livescience. "In contrast to the fruit fly that has one eightieth the body size and flaps its wings 200 times each second, the much larger honeybee flaps its wings 230 times every second."
This was a surprise because as insects get smaller, their aerodynamic performance decreases and to compensate, they tend to flap their wings faster.
"And this was just for hovering,"….said of the bees. "They also have to transfer pollen and nectar and carry large loads, sometimes as much as their body mass, for the rest of the colony."
For instance, some wings are superhydrophobic, due to a clever combination of natural chemistry and their detailed structure at the nanoscopic scale. This means that the wing cannot become wet, the tiniest droplet of water is instantly repelled. Likewise, other insect wing surfaces are almost frictionless, so that any tiny dust particles that might stick are sloughed away with minimal force.
Biologists and engineers have long known that insect wings are more complex than just flat, rigid flapping plates.
Researchers are one step closer to creating a micro-aircraft that flies with the manoeuvrability and energy efficiency of an insect after decoding the aerodynamic secrets of insect flight.
The breakthrough result, published in the journal Science this week, means engineers understand for the first time the aerodynamic secrets of one of Nature's most efficient flyers – information vital to the creation of miniature robot flyers for use in situations such as search and rescue, military applications and inspecting hazardous environments.
"An insect's delicately structured wings, with their twists and curves, and ridged and wrinkled surfaces, are about as far away as you can get from the streamlined wing of an aircraft,"
"Locusts are an interesting insect for engineers to study because of their ability to fly extremely long distances on very limited energy reserves."
Once the computer model of the locust wing movement was perfected, the researchers ran modified simulations to find out why the wing structure was so complex.
Dr…from the University of New South Wales (UNSW) in Australia, and a team of animal flight researchers from Oxford University's Department of Zoology, used high-speed digital video cameras to film locusts in action in a wind tunnel, capturing how the shape of a locust's wing changes in flight. They used that information to create a computer model which recreates the airflow and thrust generated by the complex flapping movement.
STABILIZATION and MANUEVERABILITY
Insects in flight must somehow calculate and control their height above the ground, and researchers reporting online on August 19 in Current Biology, have new insight into how fruit flies do it. The answer is simpler than expected.
Orchid bees swing their hind legs forward to reach top speed, a new study finds. The legs also generate lift, which keeps the bees balanced and helps prevent rolling
New research shows some bees brace themselves against wind and turbulence by extending their sturdy hind legs while flying.
"This increases the bees' moment of inertia and reduces rolling…much like a spinning ice skater who extends her arms to slow down."
Insects coordinate their wing movements with exquisite timing to generate a lift force. The key is how wings shed vortices from their edges. Vortices are moving parcels of air which carry away momentum, so like the air streams from a propeller they can generate a 'back' force on the object that sheds them.
Insects in flight must somehow calculate and control their height above the ground. The flies establish an altitude set point on the basis of nearby horizontal edges and tend to fly at the same height as those features. The results also provide confirmation of two other strategies that flies use to keep themselves stable and avoid collisions. If they see the world around them "moving"—for instance, if they are pushed down by a gust of wind—they will alter their flight to compensate. If the world beneath them appears to rapidly expand, as it would if they were hurtling toward the ground, they veer up to avoid crashing. Both of these mechanisms help maintain stability, but they don't set a specific altitude, the researchers said.
It's possible that other insects use different flight strategies. Even fruit flies might use different methods for flight control depending on the circumstances, the researchers said. For instance, edge tracking might be what they depend on to explore a local environment. When migrating across a desert, they might do something else entirely.
There is still plenty of exploring left to do. "We have identified one specific set of reflexes, but we still don't understand the neural mechanisms responsible."
The findings might have practical applications, he added. For example, they could come in handy for working out the ideal rules of operation for flying robots.
As the fly responded to virtual objects flying around it, the scientists used a fluorescent microscope to watch how its brain processed the images. Compared to people, who can distinguish a maximum of 25 discrete images per second, blowflies are visual virtuosos: They can sense up to 100 separate images per second and respond fast enough to change their flight direction.
The German scientists hope what they discover about insect vision will help build better flying robots. And they’re not the only ones studying flies in a flight simulator — a group led by…at the California Institute of Technology has used a similar setup, called Fly-O-Vision , to learn about muscle coordination and visual processing in fruit flies. ( http://www.wired.com/wiredscience/2009/07/flysim/)
Flies display a sophisticated suite of aerial behaviours that require rapid sensory-motor processing. Like all insects, flight control in flies is mediated in part by motion-sensitive visual interneurons that project to steering motor circuitry within the thorax. Flies, however, possess a unique flight control equilibrium sense that is encoded by mechanoreceptors at the base of the halteres, small dumb-bell-shaped organs derived through evolutionary transformation of the hind wings.
The results of uni- and bilateral ablation experiments demonstrate that the halteres are required for these stability reflexes. The results also confirm that halteres encode angular velocity of the body by detecting the Coriolis forces that result from the linear motion of the haltere within the rotating frame of reference of the fly's thorax. By rotating the flight arena at different orientations, it was possible to construct a complete directional tuning map of the haltere-mediated reflexes. The directional tuning of the reflex is quite linear such that the kinematic responses vary as simple trigonometric functions of stimulus orientation. The reflexes function primarily to stabilize pitch and yaw within the horizontal plane.
Halteres operate as vibrating structure gyroscopes. They flap up and down as the wings do and tend to maintain their plane of vibration. If the body of the insect changes direction in flight or rotates about its axis, a Coriolis force develops on the vibrating haltere, deflecting it from its stroke plane. The animal detects this deflection with sensory organs known as campaniform sensilla located at the base of the halteres. The planes of vibration of the two halteres are orthogonal, each forming an angle of about 45 degrees with the axis of the insect.
Halteres thus act as a balancing and guidance system, helping these insects to perform their fast aerobatics. In addition to providing rapid feedback to the muscles steering the wings, they also play an important role in stabilizing the head during flight.
The halteres, beating out of sync with the forewings, are the key to the fly's aerodynamic prowess.
"Flies are the most accomplished fliers on the planet in terms of aerodynamics. "They can do things no other animal can, like land on ceilings or inclined surfaces. And they are especially deft at takeoffs and landings -- their skill far exceeds that of any other insect or bird."
To fly successfully through unpredictable environments, aerial microrobots -- like insects, nature's nimblest fliers -- have to negotiate conditions that change second-by-second. Insects usually accomplish this by flapping their wings in unison, a process whose kinematic and aerodynamic basis remains poorly understood.
They used high-speed digital cameras to photograph the wing motion of the bugs, and found that locust wings curve strongly during flight.
The researchers input their measurements into a three-dimensional computer simulation — the first to include wings' complex curves. Within the model, the researchers tested different scenarios and removed certain wing features to explore the aerodynamic effects.
The team found that twisting wings are much more efficient than flat wings.
"If you change from a flat-plane wing to a twisted wing, it requires 50 percent less power to generate the same lift, which is a huge savings," said…of the University of Oxford in England.
The model revealed that curving wings are better able to create the right airflow while causing a minimum of drag downwards.
The dragonfly is an aerial acrobat. It's able to fly fast and slow, backward and forward. Flapping four wings actually achieved lift with more efficiency than flapping just two wings. When the robot's hind wings flapped one-quarter of a wing beat ahead of the front wings, the team reports, the hind wings were able to capture the rush of air sent by the front wings and produce lift with 22% less power than two-winged insects require. Flapping in phase has benefits, too: When real dragonflies synchronize their wing beats, they are able to lift off and accelerate better than if they used only two wings or four out-of-sync wings, the authors say. Engineers may be able to apply these findings to building the next generation of flapping micro air vehicles.
The researchers, from the Illinois Institute of Technology (IIT), Caltech and the University of Vermont, merged two distinct technologies, intense X-ray beams and electronic flight simulators, to study how insect muscles can generate such extraordinary levels of power. The results are published in the British journal Nature today.
Lead researcher…of IIT said that the research has widespread implications. “Flying insects are among the most successful species in the animal kingdom. The ways in which the wing muscles in these insects generate enough power for flight is not completely understood. Insect muscles differ from animal muscles in that they do not need a nerve impulse for every contraction but instead are activated by stretch. The means by which these ‘stretch-activated muscles' are turned on and off at high speed — one wing beat takes 5/1000th of a second — has been a mystery.”
The team used extremely bright beams of X-rays at the BioCAT facility (a NIH- supported research center developed by IIT) at the APS and a “virtual-reality flight simulator” for flies — designed by collaborator Michael Dickinson of Caltech — to probe to the muscles in a flying fruit fly.
GUIDANCE and LANDING
Bees record the angle from the sun as they leave the hive and use the reciprocal angle to return, after adjusting for the sun’s movement over time…but when it’s windy, the bees are in danger of getting blown off course…Bees get their direction from the sun. They learn their positions from how the landscape moves across their field of vision…Scientists call this optical flow….Bees use the angle of optical flow to compenstate for the wind…it implies some puzzling computations are going on in their brains…”
Enormous numbers of migratory moths that fly high above our heads throughout the night aren't at the mercy of the winds that propel them toward their final destinations, researchers report online on April 3rd in Current Biology. Rather, they rely on sophisticated behaviors to control their flight direction, and to speed their long-distance journeys into areas suitable for the next generation of moths.
While it isn't yet clear exactly how they do it, the researchers said the findings offer the first hard evidence for a compass in nocturnally migrating insects.
How do moths stay aloft? With their antennae, of course. When your wingspan is just three inches across, the slightest breeze becomes a gale, and knowing which way is up becomes a matter of life and death. Now, a research team reports that moths stabilize their flight by using their antennae as gyroscopic sensors.
Rotational inertia keeps a spinning top balancing on its tip: If you try to knock it over, the Coriolis force pushes it to the side instead. The size of that force depends on how fast the top is spinning. Engineers measure the corrective force on calibrated gyroscopes to keep aircraft and ballistic missiles on a level course. So when… began filming the movements of moth antennae with a high-speed camera, he wanted to understand how the animals convert the speed of air rushing by into nerve impulses. The millimeter-sized antenna movements were too small to support the flow-sensor hypothesis, but when...did the math, he realized they were large enough to register Coriolis forces. …took recordings from the Johnston's organ, a mechanosensor at the base of the antenna, and found that it was most sensitive to vibrations at twice the wingbeat frequency, just as his gyroscopic hypothesis predicted. With this signal, the moth could be measuring every twist and turn of its body as it soared through the night sky.
"This is something an engineer would not think of while sitting in an armchair and thinking about how to land an aircraft," said…a neuroscientist at the Queensland Brain Institute at the University of Queensland and the Australian Research Council's Vision Centre in Brisbane. "This is something we wouldn't have thought of if we hadn't watched bees do their landings."
"We don't know how they're doing it," he said, "But they're doing it."
If their landing surface was flat, the researchers report today in the Journal of Experimental Biology that bees simply touched down back legs first.
If the platform was anywhere between vertical and upside-down, on the other hand, the insects made contact with their antennae first, by pointing them almost perpendicular to the platform. Then, the bees hauled their front legs up and finished with a flip-like maneuver to get their mid-legs and rear legs onto the surface.
It's a graceful and acrobatic motion that would be well suited to aircraft design. Current landing systems use radiation-emitting systems, which are detectable and often undesirable for military applications.
It's a beautiful way of landing using biological autopilot.”
The signals pass on to a second set of neurons that connect to the neck muscles, and stabilise the fly’s head and thus its line of sight.
Lead researcher…from Imperial’s Department of Bioengineering says the pathway from visual signal to head movement is ingeniously designed: it uses information from both eyes, is direct, and does not require heavy computing power. He continues:
“Anyone who has watched one fly chasing another at incredibly high speed, without crashing or bumping into anything, can appreciate the high-end flight performance of these animals.
"The brains of insects measure the pattern of image motion and use it to perceive the world in 3-D to avoid collisions with obstacles and to perform smooth landings."
When insects fly, the image of the ground beneath them sweeps backward across their visual field in a way that depends both on the insect's height above the ground and on its speed relative to the ground--essentially, the higher the insect, the slower the ground will appear to move below it. This visual sweep, known as "optic flow," therefore potentially provides crucial information to the insect about its position relative to the ground, but it remains unclear exactly how such information is translated in a way that helps keep insects from crashing during flight.
Vision guides flight behaviour in numerous insects. Despite their small brain, insects easily outperform current man-made autonomous vehicles in many respects. Examples are the virtuosic chasing manoeuvres male flies perform as part of their mating behaviour and the ability of bees to assess, on the basis of visual motion cues, the distance travelled in a novel environment. Analyses at both the behavioural and neuronal levels are beginning to unveil reasons for such extraordinary capabilities of insects. One recipe for their success is the adaptation of visual information processing to the specific requirements of the behavioural tasks and to the specific spatiotemporal properties of the natural input.
The extraordinary flying ability of the dragonfly has been the subject of ongoing research by…from the Centre for Visual Sciences at ANU. He attributes their dazzling aerial control to their remarkable vision.
“What underlies their exceptional flight ability is excellent vision.”
As well as beetles, they are investigating flies, moths and dragonflies because of their "as-yet unmatched flight capabilities and increasingly well understood muscular and nervous systems".
The better we understand the functioning of insect wings, the more subtle and beautiful their designs appear … Structures are traditionally designed to deform as little as possible; mechanisms are designed to move component parts in predictable ways. Insect wings combine both in one, using components with a wide range of elastic properties, elegantly assembled to allow appropriate deformations in response to appropriate forces and to make the best possible use of the air.
(Robin J. Wootton, "The Mechanical Design of Insect Wings," Scientific American , vol. 263, November 1990, p. 120.)
1. I did not research thermal regulation, sexual signaling, wing hooks, and other details of insect wing design f or this article.
2. If the obligatory homage to the god of evolutionism is omitted from the research into insect flight absolutely nothing would change from the real scientific discoveries. An egregious example from “ Secrets of insect flight revealed” is: "Biological systems have been optimised through evolutionary pressures over millions of years, and offer many examples of performance that far outstrips what we can achieve artificially.”
3. Air Force Bugbots in animation:
4. Flight for Sore Eyes