Air Date: November 4, 2009
During a hurricane, it is better to have windows open than closed.
The MythBusters first performed a small-scale test using a box with window panels on all sides and with pneumatic valves attached to the windows. In a wind tunnel, it was judged that having all windows open was the best option, since it provided less stress on the structure of the house. For the large-scale test, the MythBusters made use of Medusa, the world’s largest portable hurricane simulator, located at University of Florida’s Hurricane Research Facility. They built a house that was small enough to accommodate Medusa’s cowling, but otherwise built to several state codes. The house withstood the winds Medusa generated (equivalent to a Category 2 hurricane) even when the windows were closed. (The windows-open test left a mess inside the house, though.) The extra pressure exerted on the house while the windows were closed was negligibly small. The Mythbusters explained that unlike their small-scale box, the surface area of a full size house’s windows are only a fraction of the building’s total surface area, minimizing the effect. In further tests, with rain and flying debris added, the house was again left standing, but the windows were broken, resulting in a mess similar to that of the windows-open test. This meant that there would still be damage in the hurricane’s aftermath, inside or out, no matter if the windows are closed or open, and it is still best to board up one’s windows before a hurricane.
A human head dipped into liquid nitrogen for five seconds can be smashed and shattered into pieces.
For this test, Grant built a robot with a large hammer to simulate an object being smashed on the counter. Four heads heads were made using a mold of Kari’s bust, three made of ballistics gel, each with a skull and brain matter analog inside, and one completely made of ice. In the two control tests, the ice head shattered while the ballistics gel head (room temperature) only had its front part broken. The test for the head dipped into liquid nitrogen for five seconds showed a result seemingly in between the two control tests: parts of the head did shatter, but not completely. To achieve the results shown in the film, the third head had to be dipped in the liquid nitrogen for five minutes. The myth was technically busted at this point. But to really simulate human flesh and blood, the myth was then retested using two pig’s heads. The head dipped for only five seconds merely had its snout flattened while the one submerged for fifteen minutes did not even shatter, completely busting the myth.
(This myth is based on a scene from the film Jason X.)
A fresh Christmas tree doused with liquid nitrogen can spontaneously explode.
For a control test, a Christmas tree explosion was made using a detonation cord. Then, a second Christmas tree was sprayed with liquid nitrogen. But after half a hour and with the temperature of the tree plummeting to almost −330 °F (−201.1 °C), no explosion occurred, not even after Tory shot it with buck shot bullets. The myth was busted because conifers and other kinds of cold-climate trees have air spaces outside the tree cells large enough to accommodate the expanding water as it turns into ice, preventing them from freezing and thus preventing an explosion.