Hot air balloons are very fascinating mechanisms in that they allow humans to fly without physically flying. Hot air balloons consists of a basket used to carry people, an envelope (the top piece), and a burner which consists of several megawatts is also present. When heat is released from the burner, it creates buoyancy. This is because the hot air is less dense than the cooler air that surrounds it. This is known as Archimedes' principle, which states that any object regardless of its shape that is suspended in a fluid, is acted upon by an upward buoyant force equal to the weight of the fluid displaced by the object.