Specific Gravity

An 800 pound hot air balloon can ignore gravity by reducing density and increasing buoyancy. - 281

Aircraft can ignore gravity by increasing thrust and lift. - 282

Underwater air bubbles ignore gravity and float to the surface of the water. This is due to density and buoyancy of the bubble compared to the surrounding water. Gravity cannot keep the air bubble down under the water. - 283

The theory of gravity is falling down. - 284