Mythbusters vs. The Phone Book

[Christopher]

^^How long did it take you to interlace all those pages?

And is there a way to get them separated again without renting a couple of tanks? Say, by pushing inward and sliding sideways or something?

 

[CmdrAJD]

But did the pages really separate? It looked to me more like one of the phone books finally just gave out and the pages ripped away from the binding . I didn't see any kind of clean separation.

 

[Christopher]

^^No, they showed it multiple times, and though there was definitely a certain amount of tearing, I think that for the most part, the books separated.

Anyway, I disagree with their "Busted" conclusion for this. They were interpreting the myth too narrowly -- that the books were impossible to separate, period. I think that if you need to use tanks to separate them (or otherwise overwhelm the integrity of the combined entity), that confirms that the phone books cannot be pulled apart by any means accessible to the typical person.

 

[Gepard]

Speaking of movies, when Adam was doing his bit about going to the Discovery site for a deleted scene, he was dressed as Indiana Jones. I'm hoping that means the bit was recorded during the taping of a later episode which will have an Indiana Jones myth, or even be entirely devoted to them. That would be cool. "Coming up on Mythbusters -- will this refrigerator let Buster survive this atomic bomb we're about to set off?"

Entirely possible. A few months back, Adam picked up a replica Indiana Jones whip through the same "prop geek buddies" channels that he used to get the Jaws scuba tanks for their first shark week special. Then again, he also used a Hellboy Samaritan in one episode's host segment, and that had absolutely nothing to do with anything.

 

[Trekker4747]

^^How long did it take you to interlace all those pages?

And is there a way to get them separated again without renting a couple of tanks? Say, by pushing inward and sliding sideways or something?

Well, I started off interlacing them one at a time but didn't have the patience for it so I just pretty much did it a few at a time. It would seem that the pages don't need to be perfectly interlaced the books themselves just needs to be interlaced. (This gives a lot more weight to the "Chinese Finger Puzzle" cause and takes some air out of the friction cause (which is silly to begin with.)

I got the books interlaced in about 5 minutes or so.

It IS possible to release them but that itself is a bit of a challenge without damaging the books. It takes some wiggling and doing without adding pressure to the books (to cause that finger-puzzle compression effect.)

I've got to say I'm surprised all around by this, infact I just tried it with a deck of cards and it seemed to have the same effect. (The cards being slick, though, are much harder to grasp but they didn't seperate when pulled.)

 

[Christopher]

Well, I started off interlacing them one at a time but didn't have the patience for it so I just pretty much did it a few at a time. It would seem that the pages don't need to be perfectly interlaced the books themselves just needs to be interlaced. (This gives a lot more weight to the "Chinese Finger Puzzle" cause and takes some air out of the friction cause (which is silly to begin with.)

Where do you get that? Whether you do every single page or every 3-4 pages, you're still creating an immensely large surface area of contact, so friction is greatly intensified in both cases.

Besides, you talk about them as if they're separate explanations, but they're not. The "finger puzzle" model wouldn't work at all without friction. As I explained, the diagonal page orientation creates a vector perpendicular to the pull that pushes the pages closer together, but the only reason that makes any difference is because it intensifies the friction between them.

 

[Trekker4747]

Well, I started off interlacing them one at a time but didn't have the patience for it so I just pretty much did it a few at a time. It would seem that the pages don't need to be perfectly interlaced the books themselves just needs to be interlaced. (This gives a lot more weight to the "Chinese Finger Puzzle" cause and takes some air out of the friction cause (which is silly to begin with.)

Where do you get that? Whether you do every single page or every 3-4 pages, you're still creating an immensely large surface area of contact, so friction is greatly intensified in both cases.

Besides, you talk about them as if they're separate explanations, but they're not. The "finger puzzle" model wouldn't work at all without friction. As I explained, the diagonal page orientation creates a vector perpendicular to the pull that pushes the pages closer together, but the only reason that makes any difference is because it intensifies the friction between them.

Well, I guess I'm thinking of the sliding friction between the pages. It's silly to think the friction between the pages is making any difference as friction is a force that's easily overcome in that manner, as the glossy playing-cards I tried it with would have much lower friction than a phonebook.

I guess in my head it's not "friction" but pressure. Pulling on the ends of the book increases the pressure on the pages but not necessairly the friction (though I suppose it could be the same thing.)

It's the difference between me holding lightly onto something and you trying to pull it out of my hand vs. me grasping onto it with all of my strength. In the latter case your job is harder because I'm putting more pressure on the object, but is that the same as increasing the friction? I'm not sure.

I adimit to not having a great deal of fromal education in the way of physics and physics terms and it could be what I'm talking about is a "form of friction" but the graphics in the show seemed to suggest it was just the surface area of those 800 pages per book that was preventing them from being pulled apart, which in my mind seems silly. That means that if you took all 800 pages of that book and spread them out across a field, and then did that again and laid the two pieces ontop of one another you'd need those two tanks to even MOVE the top sheet of paper across the other. It seems unlikely to me that would be the case, that you'd need 8000'lbs of force to move a sheet of paper that weighs as much as a phonebook simply because it's laying on another large sheet of paper.

I just don't think sliding friction is that strong.

 

[LitmusDragon]

Fun episode. The "A" myth was particularly strong. I like the fact that they used tanks even though it wasn't really necessary (it was however the most entertaining choice). I wish Kari and Torry would dial it back a notch though. Not everything has to be a sound byte.

Jamie had some great lines this episode. "I was a hit man, not a money counter". There was something he said at the tanks too that was really funny. I can't quite remember the line though.

 

[Christopher]

I guess in my head it's not "friction" but pressure. Pulling on the ends of the book increases the pressure on the pages but not necessairly the friction (though I suppose it could be the same thing.)

The amount of friction between two surfaces is directly proportional to the pressure between them. The standard equation for sliding friction is F = μN, where F is friction, μ is the coefficient of friction between the surfaces (how "rough" they are), and N is the normal (perpendicular) force pushing them together -- in our terms, the pressure between them. If you double the pressure, you double the friction. So yeah, it is essentially the same thing.

Still, I think maybe I was wrong with what I (and the Mythbusters) said before about the increase in surface area being the key, because that equation is independent of surface area, at least for hard surfaces. So increasing the area in contact doesn't increase the friction in and of itself, counterintuitive as that may seem. I think the "finger puzzle" effect may be the key after all -- the diagonal pages convert the outward pull into an inward normal force, so friction is increased because N is increased, not because the surface area is increased. So you're probably right after all.

 

[CmdrAJD]

^^No, they showed it multiple times, and though there was definitely a certain amount of tearing, I think that for the most part, the books separated.

Ahh. Thank you. I couldn't tell for certain.