This is a very interesting question! At first glance, "civil aircraft" and "birds" seem to have no connection, but in-depth comparison, we will find that they have amazing contrasts and connections in terms of function (flight), design and evolution.
The following are the main differences between them, which can be seen from multiple dimensions:
I. Core essence: natural evolution vs human engineering
· Birds: organisms. It is the miracle of hundreds of millions of years of natural selection and evolution, and it is a life system.
· Civil aircraft: artificial machinery. It is the crystallization of human wisdom based on physics, materials science and engineering for about a hundred years.
II. Flight principle: biodynamics vs aerodynamics
Although they all use aerodynamic principles (to generate lift), the implementation methods are completely different:
Features Birds Civil Aircraft
The source of lift The wings flap, changing the shape and angle, generating thrust and lift. Fixed wings. The special section (wing shape) of the wing generates lift from Bernoulli's principle when moving forward.
The source of thrust is that the muscles of the body (mainly the pectoral muscles) drive the wings to fan. Jet engine or propeller. Inhale air, and after burning the fuel, it is sprayed at high speed to produce reaction thrust.
Control method: Change the shape, angle and body posture of the wings and tail. Extremely flexible. Through the rudder surface: airon (transverse roll), rudder (pit), rudder (yw). Flexibility is limited.
III. Structure and Materials: Organisms vs Synthetic Materials
Features Birds Civil Aircraft
Materials Organic materials: bones, muscles, feathers (keratin), skin. Light and self-healing ability. Synthetic materials: aluminum alloy, titanium alloy, carbon fiber composite materials. High strength, fatigue resistance, but unable to repair itself.
Structure Lightweight hollow skeleton with complex respiratory, circulatory and digestive systems inside. Masked skeleton structure (semi-hard shell type), the interior is the cabin, cargo hold, fuel tank and complex aeronics and hydraulic systems.
Energy Chemical energy (food) is converted into bioenergy (ATP) to provide energy for muscles. Chemical energy (aviation fuel) is burned and converted into thermal energy and mechanical energy.
IV. Intelligence and Control: Instinct and Nerve vs Computer and Program
Features Birds Civil Aircraft
Control the core brain and nervous system, relying on instinct, learning and sensory feedback. The flight management system and autopilot are controlled by computers, sensors and pilot instructions.
Navigation relies on vision, geomagnetic induction, celestial bodies, and even smell. Migratory birds have a built-in "biological map". Rely on radio navigation, inertial navigation, satellite navigation and preset flight procedures.
Decision-making is autonomous and flexible, and can cope with sudden and complex situations (such as avoiding natural enemies). The pilot operates in accordance with strict regulations and procedures, and the automated system performs most routine flights.
V. Ecology and Interaction: Ecological Links vs Traffic Nodes
· Birds: are an important part of the ecosystem (pollination, seed dissemination, pest control, and a link in the food chain), which is fully integrated with the natural environment.
· Civil aircraft: It is a node of the global transportation and economic network, which requires the support of huge ground infrastructure (airports, air traffic control, maintenance bases), and has noise and emission impacts on the environment.
An interesting contradictory connection: collision risk
Despite the huge difference, they create a dangerous connection at one point: bird strike.
The strong suction power and high speed of the aircraft will cause serious damage once the bird is sucked into the engine, which is an important threat to aviation safety. This also promotes aviation design (such as engine anti-bird collision test) and airport ecological management (bird driving).
Summarize metaphors
· Birds are like "all-round intelligent drones" created by nature, integrating power, navigation and maintenance, perfectly adapting to the environment, but with limited load and range.
· Civil aircraft are like "high-speed airbuses/cargo ships" created by humans. They have unparalleled load capacity, speed, range and safety, but rely on external systems, and the "pilot" (pilot) is separated from the "carrier" (aircraft).
In short, birds are "life that flies for survival", and civil aircraft are "man-made tools that fly to connect". The contrast between the two is the vivid embodiment of the beauty of natural evolution and the greatness of human engineering.