Episode 106: Phone Book Friction

Air 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.

busted

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.

busted

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.

confirmed

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.

busted

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.

busted

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.

busted

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.

48 Comments

  1. Tyler Austin says:

    I like the idea of trying to pull two phone books apart with force but what would’ve made that show better is if you hung a car from a rope attached to it in midair.

  2. Ron says:

    you have to revisit the car battery can cause gunpowder to explode becasue in the movie there was a insulated wire hooked to the harpoon

  3. Richard Landgraff says:

    The phone book pull is CONFIRMED. That is by using pulling items normal people can acquire like two cars. It’s easy to find two cars with all those people interested. But the Mythbusters EXCEEDED the basis of the myth by using two tanks to pull them apart. Nobody in my neighborhood owns any tanks. Next time try a couple of Tomahawk missiles to see if their boosters can pull the books apart. Come on guys, be realistic.

    • Josh says:

      They used the tanks for fun…. Why not? plus, they pointed out that it took 8,000 lbs of force to pull them apart, so it’s not like they didn’t give the myth credit.

      • Tony says:

        i would have tryed the tanks but shuold have been jets

    • ben says:

      mythbusters mach the surcamstances of the myth and then the results thay wanted to see what it would take thats the idear of the show

    • Rhyan says:

      The Myth said impossible therefore by the tanks pulling it apart it is in fact possible and hereby busted

  4. anonamyous says:

    I did this as my science project for school but I only said that people can’t pull the books apart. I also tested other books like chapter and magazines. I will not tell you my results but if you want to you can try to make a sequal and see if other types of reading material can be torn apart. Have fun and thanks for the idea of my science project.

    • Cheryl says:

      For your science fair project, how did you explain WHY they couldn’t be pulled apart? What was the relationship between friction and surface area?

    • Random person says:

      I am also using this as science fair but my teacher wants 2 book sources which i cant find. Any halp would be much apreciated. Thanks

  5. Paris Kucharski says:

    Forget all those silly comments about “being realistic…” – since when is that any fun?! I thought surely the cars would do the trick for separating the phone books. The tanks were a real bonus as was your enthusiasm for pitting them against several thousand pieces of interlocked paper. ha! Now that’s a David vs. Goliath for ya. Alas, rest in peace poor Hugo. Awesome show guys!

  6. Sky says:

    it said “It is impossible to separate two interlocked phone books due to the massive amount of friction between the 800 pages of each book.” note the word “impossible”, mythbusters shows that ripping 2 interlocked phone book is very possible, if your have multiple tanks in your garages, nevertheless, the phone book were ripped apart. plus, they got tanks on the show, who doesn’t like that? like the good old mythbuster’s spirit, “If its worth doing, its worth overdoing.”

    sometimes unnecessary, but it was sure fun watching them blowing stuff up with ridiculous amount of explosive.

    good job, mythbusters, and keep up the good work.

  7. larry says:

    Say now – where do we email ya the ideas for future shows and myths?? Am having a tough time of it finding the info on your site here~
    P.S. Show us some more of the tank collection, however! Looks like that guy had some cool toys! Does anything else get out and run?! Lets see ‘em climb some big bad hills, or knock over tall trees in a single – WHAMM-O!

  8. Chris says:

    The part where Kari Grant and Tori bust the myth that you can survive the resulting blast from the shark explosion was a bit flawed because whilst you don’t get a 200 foot blast of water with 2.5 sticks of dynamite, it did kill the shark. I think that they should have checked the rupture disks after the smaller explosion and reset them if they wanted to after the bigger one. The new narrator is terribe by comparison to the old one too!! This said I have watched and loved mythbusters for years and yet have never taken the time to tell you that. Isn’t it funny how people are so quick to moan? Well probably not for you!!

  9. mike says:

    try sticky notes they work really well. for more of a challeng try putting 1 siticky not at a time between the papers.

  10. mike says:

    putting 1 siticky NOTE at a time. sorry i spelled note wrong.

  11. carlise says:

    i am doing my sience fair project on the phone book myth that you did in episode 106. i really have been looking forward to do this for a long time for my science project. you really give me a lot of information from the show and i hope i succeseed(if thats how u spell it)can you give some tips on how to start it off? send me an email or something thanks!!!!!!!!!!!!!!!

  12. carlise says:

    by the way i have an idea for a sugestion for your show, would powdered suger melt in a wood burner? or would it stay the same just be hotter, oh and of coarse the wood burner would have burning would in it. teehee !!!!!!!!!!!!!!!!!

  13. Kristi says:

    I just watched this episode this weekend and thought it would be a great experiment for my fourth graders. We are very excited to see how it works out in our classroom.

  14. *JC* says:

    Hey its very easy to pull two phone books apart! Just pull very gentle!

  15. MiMi says:

    To Richard Landgraff:

    They DID try 2 cars and that didn’t work. That’s why they resorted to tanks.

    As stated at the top of this page:

    “A pair of cars also failed at pulling the phone books apart.”

  16. Zach Williams says:

    Ive come up with a new myth for all of you to test. This is simple.
    –The myth is that one major dose of static electricity can cause an axe can to explode and shadder.

  17. Hunter says:

    I am using this for my science fair progect, the one with the phone books.I am planning on using my 2 ATVs.

  18. Hunter says:

    Ok Adam and Jamie ur AWSOME!!!!

  19. Seamus says:

    I am doing this for my science fair project and I am only using 400 page each phone books and it works amazingly even without the jig attached.

  20. Dan Goodhead says:

    You tried to pull 2 phone books appart and 2 tanks were able to do it. What about creating a rig which would hold multiple phone books on each side and see how many phone books it takes to beat the tanks. Just rememeber to recycle them after wards :)

  21. deepthroat says:

    ok first the wire needs to be insulted next the eletric source needs to be directly in the water not clamped onto the glass.

  22. Geoff says:

    I always thought that the myth was “it is not humanly possible to separate two interlocked phone books..”

    Results like this make me think there should be a fourth result like “mostly confirmed”. Plausible is used if the myth is possible but extremely unlikely. However, in this case the myth is busted only according to the exact wording of the myth. The intent of the myth has been proven.

  23. JEB says:

    Richard Landgraff I don’t know where you live, but we could find 2 Semi-trucks in my neighboorhood if need be, and I’m thinking that they would beat a tank in a towing contest.

  24. JEB says:

    As far as wording in the phone book myth. Yes, it is poorly worded cause of course you could go through and take each page apart by had the wording should have been something along the lines of,”It is not possible to pull apart two interlocked phone books.” and maybe it isn’t possible for a person… should be in there, but of course they can be separated all you have to do is the opposite of what put them together.

  25. heroicevil says:

    Thanks for the science fair project Mythbusters!

  26. Kurtis Collier says:

    I demonstrated this to my friend in ninth grade with textbooks. Now ironically enough, I must write an essay on the subject, which brought me here. P.S. I have to write the essay for punishment, but it’s okay I LOVE THE SHOW!!!

    Have you ever thought about testing the death punch? I personally know the technique and would love to give info, but I don’t know where to submit it.

  27. Zack Schwartz says:

    We are doing the phone book thing for our science fair project,

  28. Matt says:

    Well, it was rather difficult to tell from the video since the books dropped so fast, but from what I could see, the books didn’t actually “separate”, they just broke apart. AKA, the friction didn’t fail, the phone books pages did. Again, it was hard to see from the video, but I think this myth is confirmed.

    • richard says:

      Thats what i said lol the one of the phonebooks pages ripped from the spine so they didnt separate from the friction, so yea its myth comfirmed.

  29. Johannes says:

    I wonder if the force it takes to tear phone books apart increases linearly with the amount of pages interlocked :)

    Very interesting episode

    • Random person says:

      I would think so because the pages are providing the friction and if its more pages that provides more friction

  30. jt says:

    really cool show and i love watchinng it. I am using this myth fore my science experiment at school once again great show and to richard landgraff if you dont like the show dont go on the fan site

  31. Zeph says:

    I agree that the phone book myth should be confirmed. Nobody thinks phone books can withstand infinite tension just because the pages are interwoven. The only way to meaningfully define “impossible” would be that the phone books cannot be separated from each other while intact, not that phone books can never be ripped apart internally. By demonstrating that the force required to tear off the binding is less then the force required to separate the pages, they actually confirmed it!

  32. William says:

    The way they edited this episode, they didn’t say if the presure drums burst for the 2nd explosion which was big enough to kill the shark but just didn’t look like the one in the movie!

    What makes Mythbusters different than watching a sit-com is that it’s based on science. I want to know that information!

    Also, movie explosions sizes are always exaggerated, so you should really be testing what would kill a shark, not what looks like a pretty boom anyway.

    • Random person says:

      The bigger the explosion the better the show for some people its as simple as that

  33. Sarah says:

    Actually, the phone book one would be confirmed because it is technically impossible to pull anything. Every force is a pull. But thanks for the great episode I’m using it for science I’m just not sure how to explain the friction part.

  34. josh says:

    I did this with two 100 page notebooks and even that was hard to seperate. Eventualy one tore in half… Anyways i agree with geoff they should call it partly confirmed

  35. deargos says:

    I’m just surprised ya’ll r still commenting on this thread… O and the phone books were separated. They were 1, now they’re 2. Its not that difficult. The myth doesn’t say they have to rip at the pages or separate there. I think you’re all taking to many liberties with this myth…

  36. Henry says:

    i tried it with two 48 page books and it took 4 people to separate them

  37. charena says:

    phone book friction is cool we r doin our project on it

  38. CCH says:

    I am doing the Phone book friction experiment at school for science fair and am going to have the entire seventh grade (about 50 studens) pull on each side like tug of war. Thanks for the expeiment idea!

    P.S.
    I LOVE your show!!!!

  39. Matt says:

    If the tape doesn’t effect the experiement why have it. If you were scientists you would have tested this with a smaller book first, without tape, then with tape.
    I tested with a smaller book and it still worked, and used tape on the outside like you and was able to do an even smaller identical books.

    Your overall approach on things are illogical, and your conclusions always baffle me on how you come to them. There is no one answer to anything and you are always so one sided on everything.

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