A friend recently posed this question to me: let us take an arbitrary object and cut it into two pieces (not necessarily equal in any way). If we touch the two pieces back together so the object appears as it did originally, why do the bonds not reform and the object return to one solid piece?
I posed this question to some professors at a local university, and they believed that at the molecular level, the cut would be very jagged and it would become almost impossible to line up the two pieces perfectly at the molecular level as they once were. Nonetheless, they thought if we could somehow line them up, the bonds might reform on their own.
I feel van der Waals forces play an important role. Must we introduce energy into the system to form inter-molecular bonds and return the object to one piece again?
Also, I likely need some better tags for this.