February 12, 2019

Why do gliders stay in the sky?

Now you know that flying machines need thrust and lift to get off the ground. Lacking engines, gliders must make up for their lack of thrust […]
February 12, 2019

Why do airplanes fly?

Planes soar with the greatest of ease because of two forces: thrust and lift. Thrust is generated by the engines, which use either propellers or jets […]
February 12, 2019

Why do helium-filled balloons float?

Helium balloons float for the same reason a beach ball floats in water. The balloon and the air inside it weigh less than the equivalent amount […]
February 12, 2019

Why do hot-air balloons float?

Hot-air balloons are the oldest type of flight technology (pre-dating the airplane by more than 120 years) for a reason: the principle behind “lighter-than-air” flight is […]