The balloon will float until the density of its gas equals the density of the surrounding air. The density of the air decreases as altitude increases; because of gravity; gas molecules are more sparse at higher elevations. The air is thinner at high altitudes.
The latest big moment came when he landed the part of Meryl Streepâs bandmate and lover in director Jonathan Demmeâs new film, Ricki and the Flash, which opens Friday (Aug. 7). Meryl Streep Covers Gaga, Springsteen, Petty for New Film, 'Ricki and the Flash'. And it almost didnât happen.
Streep stars opposite her real-life daughter Mamie Gummer, who plays her fictional daughter; Rick Springfield, who takes on the role of a Flash member in love with Ricki; and Kevin Kline, who portrays Rickiâs long-suffering ex-husband.