Movie File Size - 4.4 MB Movie Duration - 88.61 Seconds File - MOVIES/Collapse/CollapseBigDrum.mov (Click here for larger version of movie)

Discussion

A large (48 gallon) metal drum is set up on three tripods over a Meker burner. Approximately 500 mL of water, enough to cover the bottom of the drum, is placed inside. The water and drum are then heated until the water becomes a gas. Evidence of this is seen as water vapor leaving the drum condenses to form a cloud. The vapor condenses because it cools rapidly as it mixes with the colder room temperature air. The air inside the drum is also being heated, and as it expands much of it leaves the drum, being replaced by water vapor. As soon as the water cloud is seen, the drum is sealed with a threaded cap and removed from the heat source. It is then transferred to a cart filled with ice and quickly cooled, which causes condensation of the water vapor within the can. The resulting vacuum allows the atmospheric pressure to crush the drum within a few minutes, in spectacular fashion.