Actress Amanda Bynes accused the New York Police Department of sexual harassment on Tuesday, after her arrest last week for allegedly throwing a glass bong out of her 36th-floor apartment window. Bynes, who claims the item was a vase, has been charged with reckless endangerment. Could a bong dropped from that height kill a pedestrian?
Yes. A 36th-story window is about 460 feet high. By the time a bong dropped from that height reached the ground, it would likely be traveling 115 miles per hour. (It takes a bong more than 350 feet to reach terminal velocity. Air drag would have minimal effect on the speed of the falling bong.) A typical glass bong weighs between 2 and 3 pounds, which means it would have been carrying more than 1,100 foot-pounds of kinetic energy on impact. Therefore, if the bong were unbreakable, the victim’s skull would have to absorb nearly 34,000 pounds of force to bring it to a stop before it crashed into the brain. That’s about 10 times more force than the strongest human skull can tolerate. Studies on cadavers suggest that it takes between 475 and 3,800 pounds of force to break a skull, depending on the location of the impact.
Not all of the force would be absorbed by the skull, of course. Some of it would go into shattering the glass and sending the fragments flying. It’s unlikely, however, that the breaking bong would absorb enough of the force to save the victim in the event of a direct hit. The glass in a high-quality bong is 5 millimeters thick, about as thick as a home window pane. Imagine trying to shatter a window at high speed with the crown of your head.
Although death is a possibility when hit in the head by a speeding bong, it would not be assured. Much would depend on where the bong struck the unlucky pedestrian, the orientation of the bong at the moment of impact, and the characteristics of the individual victim. There is as much as a fivefold difference in the amount of force required to fracture the same bone in different individuals. Even if the bong struck a victim square in the crown, there have been extraordinary feats of survival after a major collision. Five years ago, for example, a window washer in Manhattan plunged 500 feet to the ground and survived, even though many people die after a 40-foot drop.
Americans likely underestimate the destructive force of glass, because we’ve seen scores of movie scenes in which actors smash bottles over one another’s heads and continue fighting. Those bottles are usually made of candy glass, a form of sugar that simulates actual glass, to prevent injuries to actors. In the real world, people have died after having bottles smashed on their skulls.
Falling glass has killed people in the past, but window panes are more often to blame than bottles or bongs. In 1923 a 9-year-old Wisconsin boy died when a window pane dislodged from its frame, fell 60 feet, and struck him on the head. In 1999 a piece of glass fell from a 29th-story window in a building on Wabash Avenue in Chicago, killing a woman.
Explainer thanks James Kakalios of the University of Minnesota, author of The Physics of Superheroes.