Hello All, A very interesting and entertaining video that you may have spotted recently floating around the web: http://www.youtube.com/watch?v=6sIB2kL-BWc What I am wondering is, how on earth is such a massive resistance force developed? I have a few (basic) ideas: 1. The large surface area of the inter-connected leaves of paper result in a very high coefficient of friction (relative to paper-paper COF). However, surface area is considered independent of friction resistance by Coulomb/Dry Friction, therefore, are there other 'forces' at play? 2. Very efficient load transfer through the materials:- Due to the tension force in the books, the overlapping sheets are squeezed together and by F=(Mu)R, R can be large thus F can be large. 3. A combination of the above. To your agglomerated wisdom, I ask, "What's going on?"