Why this trick should be IMPOSSIBLE ft. Rodney Mullen - Skateboarding Science

Explain the physics of cutting something. Is it true that on a microscopic level that the cutting tool and the item being cut never physically touch one another? I would looovvee to see this happening on a super microscopic level... Yet... if it's true that the items never really touch one another, and they still cut... How do blades get dull so easily, and how does the item split?