The more I see the video, the less of any kind of difference I see in the bee's behavior as it attempts to land. And the "hover mode" (remember, only lasts a few thousandths of a second) is definitely no more stable than its normal flight prior to landing.
It stops moving forward, reaches down and flails around, and lowers itself in stages until it touches the surface.
It's still bucking around like it was at the beginning of the video (the body looks more stable, but look at the legs. They move to stabilize the body).
The wings don't appear to be tracing any different pattern to imply a change in flight mechanics.
And, it would be a huge stretch to call that a "perfect landing", as it's basically mimicing what helicopters already do (approach, lower gently until touching, and slowly throttle back instead of cutting power instantly).
Is it because it isn't a bird-like semi-crash (which make perfect sense, as they have more mass and kinetic energy)? We do that with our airplanes, though admittedly more smoothly (which also makes sense, as they have even more mass).
The optical trick makes a huge amount more sense, and plays in with landing being a genetic, purely evolved trait, instead of some intelligently-reasoned landing habit. Bugs don't have much for brains.
Also I think that the rate of descent is controlled by equalising the optical flow over the convex surface of the eyes so that it appears constant. This produces a gradually decreasing velocity profile as the insect comes in to land.
I'm thinking about what sort of über-complex physics engine you'd need to replicate that sort of velocity-image coordination in order to achieve such a super-smooth landing via what basically amounts to an optical illusion... it's incredible what even the most primitive of natural organs can do!
"First discovery that flying insects use an unexpectedly simple and elegant strategy for landing on flat surfaces (Biological Cybernetics 2000). Image velocity is held constant as the surface is approached, thus automatically ensuring that flight speed is close to zero at touchdown. No explicit knowledge of flight speed or height above the ground is necessary. The feasibility of this landing strategy has been successfully tested by implementation on a robotic gantry, and is presently being implemented for testing on airborne vehicles." (http://www.qbi.uq.edu.au//index.html?page=52793#novel%20low)
The lesson is that whatever flying machine we are able to design, it will always pale in comparison to Nature's flying machines. If humming birds had nothing to teach us, papers such as the following one would not be published:
"Those super-sonic eagles are extremely elegant. And, why do we bother with 747s when ostriches are so much more efficient."
For starters, please do note that I wrote flying machines. As far as I know, ostriches do not fly. Besides, supersonic is not that impressive. Hell, a rocket can move at hypersonic speeds. When you design a fighter jet that is as maneuverable and energy-efficient as a hummingbird, please let me know.
Wikipedia: "With the exception of insects, hummingbirds while in flight have the highest metabolism of all animals, a necessity in order to support the rapid beating of their wings. Their heart rate can reach as high as 1,260 beats per minute, a rate once measured in a Blue-throated Hummingbird.[9] They also consume more than their own weight in nectar each day, and to do so they must visit hundreds of flowers daily. Hummingbirds are continuously hours away from starving to death, and are able to store just enough energy to survive overnight."
Good find. But what is the efficiency of the nectar -> mechanical energy conversion? If you fly a F/A-18 at afterburner, you will be out of fuel pretty quickly, too. The issue is: how much of the chemical energy stored in the fuel is transformed into mechanical energy?
In any case, you're picking on the wrong issue. The hummingbird can hover better than a Harrier or a JSF. If you want to start an argument, pick on that.
> The issue is: how much of the chemical energy stored in the fuel is transformed into mechanical energy?
Hmm - you claimed that the hummingbird was "better", but you don't know the relative efficiency.
It's unclear how the existence of supersonic rockets tells us that birds, which can't go supersonic, are better than planes which can. There isn't a bird that has the payload of a Cessna, let alone a 747.
> The hummingbird can hover better than a Harrier or a JSF. If you want to start an argument, pick on that.
What definition of "better" are we using? I've yet to see a hummingbird which can carry a person, which a Harrier can do.
Hummingbirds are quieter than Harriers, but if I want to break something, they're rather useless.
Let us agree that this discussion is pointless due to lack of reliable performance metrics. In general, biological systems are orders of magnitude better than systems engineered by humans and, hence, I mentioned that we have a lot to learn from Nature. Sure, a hummingbird does hover but it can't attack enemy tanks like the Harrier does. We're talking apples and oranges here. However, look at the size of the brain of a hummingbird and how little power it must consume when compared to the powerful computers that run the control algorithms necessary for the JSF to hover. It's humbling. But Nature had millions and millions of years to come up with such solutions, and we, humans, have been flying for merely 106 years. Maybe we'll catch up.
> Let us agree that this discussion is pointless due to lack of reliable performance metrics.
Except that there are reliable performance metrics. We've seen a couple - cargo capacity, speed, energy efficiency, ability to destroy tanks. There are others.
> In general, biological systems are orders of magnitude better than systems engineered by humans
Hmm - weren't you just claiming that there weren't reliable performance metrics? Then in the very next sentence you claim something about the relative values of said metrics.
> hence, I mentioned that we have a lot to learn from Nature.
I suspect that this is the reason why you're so invested in the "nature is better" idea. However, the fact that we can learn from nature does not imply that nature is better.
When I studied Biology in high-school I found it beautiful but boring to study because it was too descriptive. Many years later, after having done various kinds of engineering, I must say I am amazed at living systems. Now I see connections between biological systems and systems engineered by humans. I see feedback loops everywhere. I think in terms of robustness and fragility.
Saying that "we have a lot to learn from nature" is almost a vacuous statement. Nature is so complex, that there are billions of opportunities to learn from it and to design bio-inspired systems. An example: neural processing is orders of magnitude more power-efficient that CMOS. Sure, our brain can't do arithmetic at high-speed, but if we lose a bunch of neurons, our brain still works. Humans can literally lose parts of their brain and survive and function. It's amazing. By contrast, a dust particle on a Silicon wafer is enough for a CPU to malfunction.
This fascination with nature has a dark side, too. Just because evolution has attained such quasi-perfect designs, it does not mean we can do the same. Neuromorphic electronic systems never got anywhere. People in the 1980s talked so much about analog VLSI and neural networks, and I haven't seen that much coming out of it.
The problem with being fascinated by something is that being in awe is not always the most productive way. Sometimes despizing something works much better. Whatever. I am not saying anything deep, and cheap philosophy never got anyone to actual achievement, to building actual things that actually work. Hence, I shut up.
"I confess that, in 1901, I said to my brother Orville that men would not fly for 50 years. Two years later, we ourselves were making flights. This demonstration of my inability as a prophet gave me such a shock that I have ever since distrusted myself and have refrained from all prediction."
No one has ever been able to predict where technology is going. This one is for you to tame your forecasting proclivities and for the moron who's downvoting my comments without explaining where my argument is weak. Cheers.
Say that to da Vinci. His flying machines were inspired by birds. He studied Nature and tried to build machines based on the same principles as those that allowed birds to fly. Of course, that led his astray, because it's hard to design machines that fly by flapping their wings. However, the structural part remains. Take a look at how airplanes are designed these days, and you will see that their structure somewhat resembles the bone structure of actual birds.
Last but not least: never say never, and never predict more than 10 years into the future. In 20 years your predictions might be ridiculed.
I am not sure studying things in nature and creating exact models would be a good idea. Imagine trying to model a motor bike or a car by studying Cheetah(Fastest animal on ground). Nature may inspire to model/create useful things.
We create exact models to try to fully understand what is happening in nature, and then we mix the concepts into hybrid designs. This has been done for a number of MEMS insects, and has made them so much more efficient.
It stops moving forward, reaches down and flails around, and lowers itself in stages until it touches the surface. It's still bucking around like it was at the beginning of the video (the body looks more stable, but look at the legs. They move to stabilize the body). The wings don't appear to be tracing any different pattern to imply a change in flight mechanics. And, it would be a huge stretch to call that a "perfect landing", as it's basically mimicing what helicopters already do (approach, lower gently until touching, and slowly throttle back instead of cutting power instantly).
Is it because it isn't a bird-like semi-crash (which make perfect sense, as they have more mass and kinetic energy)? We do that with our airplanes, though admittedly more smoothly (which also makes sense, as they have even more mass).
The optical trick makes a huge amount more sense, and plays in with landing being a genetic, purely evolved trait, instead of some intelligently-reasoned landing habit. Bugs don't have much for brains.