Why sharp glas is more sharper than knife

Not necessarily a true statement. Depending on the steel alloy, thickness and honing, steel may be sharper. BROKEN glass is typically sharper due to crystal shape but loses it's edge quickly. Why do you think knives are steel instead of glass? Some ceramic knives, alloys of rare earth metals are very sharp but prone to breaking if handled roughly. Obsidian breaks to form an extremely sharp but delicate edge, sharper than steel, at least for a while, actually used for surgery, but nothing for residential use. So I guess it depends on you interpretation of "sharp"

A glass knife or broken glass can be only a molecule thick on its eadge. A steel knife has a crystalline structure which looks like a saw blade under magnification. Steel is much more jagged due to this structure. http://www3.telus.net/BrentBeach/Sharpen/qx3.html Why do you ask?