See how they try to wiggle their way out of it. Han ----- Original Message ----- From: "John Gardner" <[EMAIL PROTECTED]> To: "Austin Spreadbury" <[EMAIL PROTECTED]>; "'Joseph B. Fox'" <[EMAIL PROTECTED]>; "mail" <[EMAIL PROTECTED]>; "Han Maenen" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Thursday, August 30, 2001 7:54 PM Subject: RE: Questions about measurement standards > As Austin says, inches and pounds are defined (in legislation) in metric terms. However, metric is itself defined by so much distance travelled by light in a vacuum, etc. It therefore follows that the inch and pound can also be defined by the distance of light travelled by light in a vacuum. Consequently, metric can be defined by imperial units, as well as vice versa. Just because scientists used metric when defining the distance of light, there is no inevitable reason why this should have been so. They could have used feet. So, it's a level playing field when coming to defining one system in terms of another. John > > > > On Thu, 30 Aug 2001 13:17:01 +0100, Austin Spreadbury wrote: I think it's wrong to say that metric measurements are defined in terms of imperial ones. IMHO it's quite clearly the other way around: when (for example) the inch was standardized, it was fixed at EXACTLY 25.4mm, splitting the difference between the former values of the UK and US definitions. The inch changed, not the metre, so the direction of dependency is quite clear. > > For the record, the metre is in fact now (since 1983) defined as "the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second", with the second being defined in terms of some measurable atomic constant. Austin.
