Published DateAugust 01, 2016
- Kim McDonald
When migrating over long distances, migratory birds frequently use warm, rising atmospheric currents to gain height with little energy expenditure.
Thermal soaring is a behavior that necessitates complicated decision-making in the turbulent environment of a rising column of warm air from the earth’s sun-baked surface. However, it was unknown how precisely birds navigate in this constantly shifting environment to maximize their thermal soaring until a group of biologists and physicists at the University of California, San Diego, performed a thorough computational analysis of the issue.
This week’s online Proceedings of the National Academy of Sciences journal featured mathematical models that the scientists used to illustrate how glider pilots might be able to soar more effectively by using the same learning strategies that birds use to maneuver through thermals.
According to Massimo Vergassola, a physics professor at UC San Diego, “pretty little is known about the navigation strategies used by birds to cope with these challenging conditions, mainly because past computational research examined soaring in unrealistically simplified situations.”
In order to solve the issue, he and his associatesincluding neurobiology professor Terrence Sejnowski of the Salk Institute and UC San Diegomerged numerical models of atmospheric flow with “reinforcement learning algorithms”equations that were first created to simulate the actions and enhanced performance of animals learning a new task. These algorithms were created in a way that used feedback on the glider’s soaring performance to teach it how to navigate intricate, turbulent environments.
Sejnowski claimed that Google’s DeepMind AlphaGo program, which gained notoriety in 2016 by defeating human professional go player Lee Sedol, utilized the same “reinforcement learning architecture.”
The researchers applied it to soaring performance and considered how the thermal temperature variations affected vertical velocity as well as the bank angle and angle of attack of the glider’s wings.
Vergassola explained, “The glider is able to climb and stay within the thermal core, where the lift is typically the largest, resulting in improved soaring performance, even in the presence of strong turbulent fluctuations, by sensing two environmental cuesvertical wind acceleration and torque.” When turbulence intensifies, the glider can prevent losing altitude by implementing progressively cautious and risk-averse flying techniques, like staying on the same course instead of making a turn. .
The scientists demonstrate how an untrained glider (at left) makes snap decisions and descends while a trained glider (at right) learns to use the distinctive spiraling patterns in areas of strong ascending currents, as seen in the thermal soaring of birds and gliders, in the two- and three-dimensional color graphs (above). (The colors represent the glider’s vertical wind velocity.) The trajectory’s beginning and ending are denoted by the green and red dots, respectively. ).
According to the researchers’ findings, “torque and vertical accelerations” rather than temperature variations seem to be the sensorimotor cues that best direct birds’ most efficient soaring paths through thermals.
According to their writing, “temperature was specifically shown to yield minor gains,” meaning that an instrument for autonomous flying vehicles could safely omit a temperature sensor. .
“Our research illuminates the cognitive processes that avian species may employ to effectively maneuver through turbulent thermals,” stated Vergassola. “Using this information, basic mechanical instrumentation could be designed to enable autonomous gliders to travel great distances while using the least amount of energy.” .
Sejnowski, a Howard Hughes Medical Institute Investigator, stated, “The high levels of soaring performance demonstrated in simulated turbulence could lead to the development of energy efficient autonomous gliders.”
Antonio Celani of the Abdus Salam International Center for Theoretical Physics in Trieste, Italy, and Gautam Reddy, a physicist at UC San Diego and the paper’s first author, were also part of the research team. The Simons Foundation provided funding for the study.
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Jim Clarke Institute of Sound and Vibration Research JHP
Roy Edwards wrote in message <37de1ece…@news.wave.co.nz>…
I believe that raptors and humans both learn where thermals are by using their potential to bow toward other sensors. A bird learns his local area before venturing out further. I have witnessed them repeatedly go to the same lift sources to heat (i e. my black roof in an oak forest).
It is very different to be covered in feathers and suspended in the air than it is to be enclosed in a fiberglass tube and hear whistles. Hang glider pilots acknowledge that their sense of air movement is far greater. They are able to sense air entering a thermal from the side at its base.
I used to think that was impossible, but the more I fly, the more I understand that by feeling for a thermal, I can detect it before the varios do. A bird, in my opinion, is far more aware of his surroundings than I am.
The idea that if you fly in a straight line, you will eventually hit a thermal may not seem to have much to do with the majesty of Mother Nature, but it serves our purposes. I would have a viewpoint more similar to theirs if I could get away with a 1/4-knot thermal in exchange for breakfast. They can settle for much less, so they just hit a lot more lift sources than we do.
Swifts, in my opinion, are able to see insects and smell moisture and earthy scents. I think gulls are opportunists. I think ravens are just smart. I’ve seen them sit in the same tree near a highway a lot, waiting for a semi to pass by and start a dust devil. I wish I had thought of that!.
Ah, ultra low and ultrasonic arent the same. Imagine a generator producing sound at 50 kHz or higher. It is not difficult for me to envision a subdued generator within a thermal As a former radio direction finding engineer, I can see “ears” with matched filters and hemispherical coverage functioning rather well. I wonder if .
Student napisa?(a) w wiadomo?ci: <37DDEA90…@clouddancer.com>…
Birds may or may not use unique sensory abilities to find lift, but I would anticipate that they employ a more comprehensive strategy than any one sense. They have an advantage over those of us who feel the air only through the pressure of our posteriors on the seat because of the biofeedback they receive solely from their feathers. and we are fully aware that having a sensitive backside has an advantage over any panel instrument.
zerocinco
If its a sound, they all have hearing. I completely agree if you mean a heat sensor of some kind. If it’s the glimmer in the atmosphere, they can all see fairly well.
> I think raptors learn where to find thermals in much the same way as we do > (with a possible bow towards other sensors). A bird discovers his surroundings They arrived at the same lift, as I have witnessed. e. my black roof in an oak forest).
I also go back to the same general area, but only if I had a sensor that showed me there was also a thermal there. It would be a significant confirmation if they were using search patterns for lift rather than food.
> Being out in the air covered with feathers is a lot different than being in > a fiberglass tube listening to whistles. Pilots of hang gliders confess that they They sense the motion being sideways. > > When I was a student, I thought this was impossible but the more I fly, the > more I realize that I can sense a thermal sooner than the varios by feeling > for it. A bird, in my opinion, is far more perceptive of his
Very true. It seemed that there was no more lift available recently while receiving spin instruction, so landing practice came next. I was about to start a left turn when the instructor suggested a landing pattern, so I said, “Wait a minute,” banked right, and eventually climbed 2000. No vario clues, but something in the stick or airframe. I’ve since had this incident again, and I believe it’s because I’m extremely sensitive to vibrations due to my 50,000 miles of motorcycle riding. I changed my direction right away because Hod Taylor’s flights had previously convinced me that I never commit to a turn when looking for lift. I’m not sure how I found it, but I knew something was there that time.
> It may not seem that the majesty of Mother Nature could be based upon the > theory that if you fly in a straight line, you will eventually hit a > thermal, but it works for us. If I could use a 1/4-knot thermal instead of They’ve just encountered a
This is a valid point; the only way to distinguish between “luck” and “clue” is to pay close attention right before the bird enters the thermal. Observing the bird’s head, in my opinion, ought to give an indication It’s obviously a two-person job; are there any grants available?
> I think Swifts see the bugs or smell the moisture or the odor of the earth. > I think gulls are opportunists. I think ravens are just smart. Frequently, I I wish I had thought of that!.
Perhaps glider pilots are astute businesspeople. Carl had a very slow start the day I rode in the Nimbus 4DM (no thermals in the typical spots). While he circled and searched, I was practicing choosing landing spots. Those wings, I swear, set off the rising thermal that appeared in about five minutes.
Think back to the moment the teradactyls began to thermalling; they were probably flapping a lot to try and center the thermals. The teradactyls that thermalled better likely “dumped” on the ones that did not fare as well. Remember, they didnt have cars back then for target practice. Heck, isnt that what we use P bags for?.
The people who were dumped on were most likely blinded or at the very least had corrupted CGs (big bird, big ), and they eventually crashed, getting devoured by velociraptors or something.
Only the fittest were able to reproduce and eventually become eagles.
Gapagod wrote in message <19990914135625…@ng-ft1.aol.com>…
>I think evolution plays a big part in this. > >Consider when the teradactyls first started thermalling, probabally flapping a >lot while they tried to center the thermals. The teradactyls who were ineffective Remember, >they didnt have cars back then for target practice. Indeed, is that not what we
>messed up ( big bird, big. ) , and they ended up crashing and were then.
Before the chamber pressure was changed, very mild electric shocks were administered to the birds, and heart rates were recorded to see if the birds’ responses changed. When the pressure inside the chamber changed as a result of the mild shock, the heart rate would rise. Through “operant conditioning,” the birds learned to link pressure changes and shocks.
After the birds were trained in this manner, the shocks were discontinued, but the degree of pressure changes persisted. The birds’ increased heart rate suggested that they were aware of the pressure shift because they were anticipating a shock at the same moment, which never materialized.
Ultimately, NON-soaring birds detected pressure differences equal to three feet above or below.
After that, birds with damage to their inner ear mechanisms were unable to detect any change in pressure, indicating that the pressure sensing organ is physically located in either the vestibular (balance) or auditory (hearing) systems.
Although I’m not aware of any studies done on soaring birds, one would assume that their “built-in vario” is even more sensitive than pigeons’.
Although it is evident that humans cannot sense pressure changes, any glider pilot will eventually learn that it is possible to sense vertical acceleration. This ability is thought to reside anatomically in the “butt. “.
Naturally, the best way to demonstrate this would be to take someone’s butt off and observe how it affected their thermal perception.
Jim Skydell DG-300 “8B”
Student wrote:
> Is there a consensus on how birds locate thermals?
My utterly ignorant assumption is that they have developed variocentric ears. An ear is, after all, a sealed chamber with an exterior opening that is somewhat similar.
Air will move from the “chamber” next to the eardrum to the area of lower pressure outside as the bird rises. Do they hear it or feel it? . I have no idea.
This is similar to how our own ears pop when we go up or down. It’s not hard to see how this ability would have given those soaring-like birds, which use thermals as a partial energy substitute for calories, a major advantage.
Jim Skydell wrote in article <37DEEDC5. @prodigy. net>. >>. Of course, one would have to take someone’s butt off in order to demonstrate this, and
I know some people who had this operation. only they left the butt! Jim Husaingap. @aol. com.
> Of course, to prove this, one would have to remove someones butt, and > see what it did to their thermalling ability.
In the case of some people I know next to nothing would be left. ;.) — Blue skies! Wilhelm Holtmeier PGP ID 0x5DBFFD54http://www.trustcenter.de/cgi-bin/SearchCert.cgi
When I was still a student, I had my butt chewed on occasionally, but never entirely off. I did seem to help my thermaling.
Dont birds locate thermals by watching for circling sailplanes?
No, thats how thermals decide to trigger…
“John M. Morgan” wrote:
> Dont birds locate thermals by watching for circling sailplanes? >.
When a jungle bird faces its first set of challenges in the autumn, it truly does that. I used to joke around with a few of them on a local flight.
Eventually, as they gain more expertise, they learn about us.
— Bert Willing ———– Caproni Calif A21S D-6600 Come fly at La Motte du Caire in the French Alps:http://www.decollage.org/la_motte/
Bert Willing wrote:
> “John M. Morgan wrote: I used to > > As they become more experienced, they eventually come to know about us .
They then determine the location of the _really_ good thermal, which is a few hundred meters away from the sailplane that is circling.
Lars Peder — _________________________________________________________________________
_________________________________________ Id rather be soaring… __________
“Quality is the common ground for art and technology”
Yup. The thermal is actually a few hundred yards away from the sailplane when they take off.
— Brett Rabe br. @uswest. net / 612. 664. 3078 ISE U S WEST – Internet Services.
Age is a very high price to pay for maturity.
FAQ
How do birds know where thermals are?
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How do gliders know where thermals are?
How do buzzards find thermals?