Study the fundamental differences between science and engineering by comparison between eye and camera, bird flying and aircraft.

 

Study the fundamental differences between science and engineering by comparison between eye and camera, bird flying and aircraft.

Eye and Camera

Structure of camera and human eye along with the similarities and difference is explained.

(Comparison between camera and eye)

Similarities between camera and eye

Part of the                Corresponding                                Function

Camera                     part of eye   

-----------------------------------------------------------------------------------------------------------

Aperture                   Pupil                 --------------------  Light enters the eye through the

                                                                                        Pupil/aperture

Diaphragm               Iris                     -------------------- The iris/ diaphragm regulates the

                                                                                        amount of light entering the

                                                                                        eye/camera

lens                          Lens                  ---------------------  Focus light and image on the                                                                             retina in eye and film in camera  

Film                        Retina               ----------------------  The part on which images are

                                                                                       formed   

Black paint             Choroid            ----------------------  The dark colored melanin    

                                                                                       Pigment in the choroid and

                                                                                       black paint in the camera

                                                                                       absorbs light and limits reflections

                                                                                       within the eye that could  degrade

                                                                                       vision

 

Differences between camera and human eye

CAMERA                                                                    HUMAN EYE                                

Focal length of lens is fixed                                         Focal length of the lens be changed

Photographic film retains the                                       Retina retains the impression of

Image permanently                                                      an image for only 1/16^th second

 

A photograph has to be changed                                 Same retina can be used viewing

For getting next image                                                 viewing unlimited images

 

Image is formed on photographic                               Image is formed on retina which

Film and processing can be done through                  is further processed in brain

Computer

BIRDS AND AIRCRAFT

 

Both birds and planes are capable of flying and the science has shown that a principle

Behind this ability of flying in both cases is same but the mechanism is different

The basic principle of plying is based of Bernoulli’s principle

The particles in air are always moving. Air like a fluid will always move from a high pressure area to a low pressure. He found that fast moving air has lower pressure and slow moving air has higher pressure. It is this Bermoulli’s principle that helped us how birds and airplanes can fly.

          When air rushes past the wing of a plane, it flows above and below the wing. The top part of the wing is rounded and the bottom is fairly straight. Therefore, air rushing over the top of the wing has to travel a greater distance to the back of the wing compared to the bottom

          As a result, the air on the top of the wing has to travel faster to keep up with the air underneath. This creates a low pressure area on the top on the wing and high pressure area on the bottom. The difference of pressures on the surfaces of the wing creates lift(the upward force that keeps planes and birds aloft,)

Forces that act on birds during flight

 

01       Lift:    The force that pushes upward, created by the movement of air over and       under the wings.

02       Drag:  The force of the air pressing against the birds and slowing them down.

03       Thrust:  The force that moves the bird forward, caused when a bird flaps its wings.

04       Propulsion:  It means to push forward or drive an object forward. A propulsion system is a machine that produces thrust.

                       Newton’s Third Law: For  every action there is an equal and opposite reaction. Thrust often comes from muscles or engines.

Characteristics of Birds

Important things that birds have that help them keep their weight low are:

     01              Feathers---are light, flexible, used for protection and also to keep the                                        bird warm

02              Hollow bones:---- are very light

03              Strong muscles

A comparison between flying of aeroplane and flying of birds is shown in below.

Comparison between flying of aeroplane and birds

Function                               part of the aeroplane                    part of the birds

Lift                                         propellers/airfoil                       Muscles

Drag                                       Streamlined shape                      Light weight skeleton and  

                                                                                                   streamlined shape 

Thrust                                    Movement of aeroplane              Flapping of wings

                                               and wings by engine

 Control                                  Wings                                          Tail and wing

Propulsion                             Engine                                           Muscles