The yoctometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: ym) or yoctometer (American spelling) is an SI measure of length that is equal to {10^|-24} (yocto) of a metre. A yoctometre is equivalent to 1/100 of the diameter of an electron, and 1/100,000 the diameter of a proton or neutron. In term...