Dear sir, i visited ur site about the definitons of meter. i want to know that In 1983 why the definition of meter has been changed from a physical meter to quantum meter. Thnx.
The change was made for two reasons:
1) It protects SI against a possible or improbable destruction of the prototype metre at the headquarters of the Bureau International des Poids et Mesures at S�vres, France.
2) The new standard can be measured at least 10 times more exactly than the metal bar standards.
The kilogram is now the only unit that is based on a material prototype. Attempts are being made to find a way to determine a kilogram without requiring a comparison with a physicical prototype -- Joseph B. Reid 17 Glebe Road West Toronto M5P 1C8 Telephone 416-486-6071
