Resumen de A new bubble-based demonstration of free-fall weightlessness

Ivana M. Krulj, Josip Slisko Ignjatov

• According to the equivalence principle, there is no local gravity field inside free-falling systems. Consequently, all gravity-related forces disappear. Weightless water is unable to exert a buoyant force. Its absence in free-falling systems was previously demonstrated by showing that a submerged object whose density is lower than that of water does not go up in free fall. In one demonstration, the submerged object was a Cartesian diver,1 and in another, it was an air bubble.2 In the second demonstration, the air bubble is inserted into the water by blowing through a vertical plastic straw.