Can gravity be defied? This writing on the Kenya Airport Authority bus "where we defy gravity." Really perturbed my mind.
Nevertheless, really, can gravity be defied? If yes, do airplanes defy gravity? How?
These disturbing thoughts led me to conduct extensive research on real physics.
Newton’s LAW of universal gravitation states that every object in the universe with a force is directly proportional to the product of their masses and inversely proportional to the square of their distances.
So what principle do planes work on, and how does the principle relate to gravity?
First, understanding how planes work well needs to lay out the forces that form the basic working principle of airplanes.
Weight: This is the downward force acting on the plane. The earth’s "gravitational force" pull helps to keep the plane grounded until acted upon by the opposing force >>>" lift" <<<<
Lift: This is the upward force acting on the plane and helps keep the plane afloat without falling on the ground.
Thrust: This is the force that pushes the plane forward provided by the propeller
Drag: This is the force that slows the forward thrust of a plane, greatly contributed by the increased changes in air pressure and friction.
Next, let us see how the following forces play during lift off of planes and during landing considering the two elements contributing to an airplane’s wing’s ability to create lift.
ANGLE OF ATTACK
Refers to the slight angle of an airplane concerning the oncoming air, which allows the plane to catch the air as it moves forward. The air molecules are split into two directions, with the underneath air creating downwash, and according to Newton’s third law, the plane is pushed forward by an equal force.
DIFFERENCE IN AIR PRESSURE
As the plane moves forward, the air is split into two, just above the wing and below the wings. The air above the plane is of low pressure, while that below is below pressure. Also referred to as Bernoulli’s principle.
After a careful review of the principles behind the operation of lift of planes, we can conclude that planes do not defy gravity; instead, the tilt and the area of the wings of a plane manipulate the air particles around them, creating a strong enough lift that the force of gravity is overcome by the forces beneath the wings.
reference Proving Universal Gravitation by Warping Space-Time | Physics or Astronomy Science Fair Projects. sciencefairexperiments.org/Physics/Proving-..