The MythBusters The MythBusters

MythBusters Episode 106: Phone Book Friction

Premier Date: September 10, 2008

It is impossible to separate two interlocked phone books due to the massive amount of friction between the 800 pages of each book.


The MythBusters tried to pull the two phone books apart with human power, which was unsuccessful. A pair of cars also failed at pulling the phone books apart. Finally, the MythBusters resorted to using an M551 Sheridan light tank and an M113 armored personnel carrier, which were able to pull the phone books apart. While the myth was busted, the MythBusters pointed out that it took 8,000 pounds of force to pull the phone books apart, meaning that you could literally hang two full size cars from it.

The following myths are derived from the ending sequence of the film Deep Blue Sea, in which a huge shark is defeated with a harpoon gun, a car battery, and some black powder.

Gunpowder can be set off by a car battery by using seawater to conduct the spark.


The spark created by the car battery was did not conduct through seawater and ignite the gunpowder.

A harpoon gun is accurate up to 100 feet.


Tory was able to accurately hit a replica shark with a harpoon gun from this distance.

Ten flares contain enough black powder to match two and a half sticks of dynamite.


Grant first began by trying to take apart several tube flares, which took far longer than it did in the movie. After measuring the powder, the Build Team calculated that it would take at least 450 flares to provide the gunpowder equivalent two and a half sticks of dynamite, instead of the ten flares shown in the movie.

Two and a half sticks of dynamite will cause a tremendous explosion.


The Build Team first tested this myth using a canister with the same dimensions as in the movie, which could only hold 28 grams of powder, which did not even disturb the surface of the water, and caused minimal damage to the replica shark. Two and a half sticks of dynamite (681 grams of powder), was enough to destroy the shark and cause a large explosion, but not anywhere as large as seen in the movie. The Build Team also concluded that the weight of a canister containing two and a half sticks of dynamite would make the harpoon too heavy to hit a target 100 feet away. Eventually, to create an explosion matching the movie explosion’s magnitude, 400 pounds of powder was used.

A person can survive a large underwater explosion at a distance of 50 feet.


The Build Team tested this myth using rigs containing rupture discs that would burst if they were hit with a lethal pressure of 500 psi. They placed several in varying distances from the explosion, and determined that even being 100 feet from an explosion of the size seen in the movie would be fatal.