  Using the soap bubble technique, we visualize the dynamics of unconfined
hydrogen-air flames using high speed schlieren video. We show that for
sufficiently weak mixtures, i.e., low flame speeds, buoyancy effects become
important. Flame balls of a critical dimension begin to rise. The experiments
are found in very good agreement with the scaling laws proposed by Zingale and
Dursi. We report the results in a fluid dynamics video.
