“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. 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.” (The Conversation)
So begins the article over at The Conversation, explaining why it’s impossible to pull apart interleaved phone books. It’s a fascinating read, and it’s all to do with friction. In short: the harder you pull, the closer the pages move to each other, and the greater the friction between them.
The article includes two videos, one of which is shown above. It shows just how difficult it is to pull apart the phone books, even with heavy machinery.
Really interesting stuff. Onwards!