Skydiving is nothing but physics or defying science, but there are some basics concepts involved in the technique behind it. Once you dive into the sky, there are essentially two forces that are acting on you:
- Earth’s gravity pulling you straight down,
- Friction with the air.
The friction with the air is the force that push you up against the force pulling you downwards i.e., Gravitational pull. So basically it pushes up you and your equipment.
As your speed increases, air resistance also increases, so when you first start dropping and are moving slowly, gravity is stronger than the air resistance. As soon as you speed up, you start accelerating towards the ground. However, the faster you drop, the stronger the air resistance becomes. Eventually you move so fast, the air resistance is equal to the gravitational strength. This is the point where you have reached terminal velocity for your current body position.
Your air resistance also depends on the shape of the object (you and accessories). So by tucking in your arms and legs you can reach a faster terminal velocity if compared to arms and legs being spread. Skydivers also do so to achieve a position of dynamic stability.