On the precision of a length measurement

Abstract

We show that quantum mechanics and general relativity imply the existence of a minimal length. To be more precise, we show that no operational device subject to quantum mechanics, general relativity and causality could exclude the discreteness of spacetime on lengths shorter than the Plan& length. We then consider the fundamental limit coming from quantum mechanics, general relativity and causality on the precision of length measurement. © 2008 by World Scientific Publishing Co. Pte. Ltd.