> This just means the "length of a second" wanders around randomly and is thus useless Why would it? My redefinition just means the length of a second is defin

> This just means the "length of a second" wanders around randomly and is thus useless Why would it? My redefinition just means the length of a second is defined as a given number of cycles of caesium in a gravitational field equivalent to that of Greenwich. If you're in a different gravitational field, you'll just have to convert the values easily.