People, trucks and even military tanks have tried and failed the task of pulling apart two phone books lying face up with their pages interleaved, like a shuffled deck of cards.
Take two books and interleave all their pages one by one. Now try and pull them apart by their spines. Impossible, right? You may have seen this trick before: it’s used as a classic example of the extreme power of friction.
How Can Paper Be Strong Enough to Lift Two Tons? A simple trick that makes ordinary books as strong as steel has some very complicated science behind it.
While physicists have long known that this must be due to enormous frictional forces, exactly how these forces are generated has been an enigma – until now.