A bunch of pelicans, seagulls, and goose are flying around on air. An air show that so awesome! There is some spiteness when human look at this air show. Obviously, all of human intelligent still can not compete this bird’s capability that can fly without using any instrument technology such as big engine that release disturb noise. What its secret? How the Bird can fly, to opposite all limit causing by their weight and earth gravitation? They even always fly as a cohesive groups. Are the human loose?
This air show that has very old age involving 4 fundamentals forcein physics. Some of them are:
- Drag Force. This force is yielded from the collides of air molecules with bird’s body. The direction of this force are always opposite with the direction of bird’s way. Meanwhile the value of this force depending on surface area of the bird and its velocity. The bigger surface area, the bigger too its drag force. An illustration of this can be found when we walk out opposite the big wind. This force will be bigger if we open up our arms widely or we walk faster.
- Lift Force, it’s force that lifting up the bird. There is two things can emerge this lift force: wing’s flutter and airstream pass out the wings. When the bird flutter down the wings, its wings are press down the air, so that the air will be press in the opposite and lift up the bird (Newton’s third law). The faster wings fluttering, the bigger will be its lift force. So it’s causing pigeon that will fly must flutter its wings faster. The big size bird like Kori Bustard from Africa of course must have strong thorax tendon in order to fluttering wings faster tolift up its fat body (19 kg).
- Thrust, it’s force that push forward the bird. This force is yielded by wings fluttering like fall down ‘8’. The wings fluttering yielded some vortex that are able to give urge force to the bird in the air. The power of this force depend on the strong of fly muscle.
- Weight, it’s earth gravity force. It’s value depend on the bird’s mass. The direction of this force is down to the ground.
- The combination of the forces that had mentioned before is used by the birds to doing atraction such as parachuting, gliding, flight, and soaring.
Parachuting
Parachuting is the downfall manuver on air. The elevation of this manuver can bigger than 45o to horizontal. To be able doing this manuver, the hawk must increase its drag force with extent its surface area (for example, extent its wings).
Gliding
Gliding is the downfall manuver that had elevation a few little than 45o with horizontal. The main purpose of gliding is to glide as flat as possible. This action doing with decreasing the drag force. In gliding, the fulmars are able to reach distance till 8.5 metres, but only move down 1 metre. The vultures are doing better, this birds can reach the distance till 22 metre with only 1 metre move down.
Flight
Flight is done by fluttering the wings. The fluttering of wings are used to yielded thrust and lift force. This thrust force and lift force can be arranged by the birds to control the direction, velocity, and its altitude. When the hawk move down with high velocity to catch mouse, the hawk decrease the drag force by slim its body or bent up its wings. When close to its bait, the hawk slowing down its movement with increase the force by extent its wings (what a remarkable thinking by this hawk.....).
Soaring
This manuver is move up without fluttering the wings. This movement can be done by using airstream. Causing by the sun, the hot air will be lift up and create the airstream upright. This airstream used by the hawk to soaring without flutter its wings. The albatross or seagull, and other. To soaring, the albatross using airstream that reflected by sea surface. That’s why the albatross always fly around near with sea surface.
Flying Parade of The Birds
Have you ever see a bunch of birds migrate? The gooses usually fly in groups form up a beauty parade, rarely found that a goose fly far alone itself. Beside to security reason from predator attack, this togetherness decrease lost risk in the way. In migrating from one place to another this gooses using earth magnetic field as compass.
In their marching, this gooses often form up a ‘V’ formation. The front goose (the leader) is the key way that must work hard to “destroy” drag force, so that another gooses in the back can move easily. When the leader get fatigue, his friend as soon as possible replace him (the actually not selfish....).
On their ‘V’ formation, this gooses movement very harmonic so that they are not necessary to give the big power for such long trip. This gooses is look very cohesive, look like they never lost direction. Actually, another mistake of wrong direction could happen, but that foul is eliminated faster so that never seen as effect fly direction. If one goose deviate from group, then another goose will adapt so the way that be reformation but not the fly direction. This concept is often used in modern management. According to this, if there is someone had the idea that could deviate company direction but can gain profit for the company, then his friends will adapted, that this man will not be isolated. His friends will adapt so that company’s vision will not be changed.
It’s passionate to look the birds movement. Actually in physics we must learn much from the birds. So beauty and awesome what their physics show us in the air during a million years until we feel that we are nothing.
