brian0918 writes "Nature reports that researchers at Dresden University believe that sabres from Damascus dating back to 900 AD were formed with help from carbon nanotubes. From the article: 'Sabres from Damascus are made from a type of steel called wootz. But the secret of the swords' manufacture was lost in the eighteenth century.' At high temperatures, impurities in the metal 'could have catalyzed the growth of nanotubes from carbon in the burning wood and leaves used to make the wootz, Paufler suggests. These tubes could then have filled with cementite to produce the wires in the patterned blades, he says.'"