Eric, I have to agree with John on this. Units only become meaningful with use. This is why SI is so superior. You can pick a prefix that puts the numbers in a meaningful range.
The truth is, those you are trying to dumb down to by using AU don’t understand AU either. Harold From: John M. Steele Sent: Friday, 2014-06-27 06:40 To: U.S. Metric Association Subject: [USMA:54069] Re: New supplement to the SI Brochure But gigameters, terameters, petameters, etc. are not. That's what prefixes are for, and they continue to a range that could handle the universe. The AU is approximately 149.6 Gm, the parsec about 30.86 Pm. ------------------------------------------------------------------------------ From: Eric L Shuman <[email protected]> To: U.S. Metric Association <[email protected]> Cc: U.S. Metric Association <[email protected]> Sent: Friday, June 27, 2014 2:48 AM Subject: [USMA:54068] Re: New supplement to the SI Brochure Because the numbers are beyond human comprehension. This part of my job requires me to provide some meaningful sense of proportion. Earth is 149 597 871 km from the Sun. That's our STARTING point. Meters, kilometers, miles, furlongs, parasangs and stadia are totally meaningless on the astronomical scale. On 26 June 2014 17:45, Harold_Potsdamer <[email protected]> wrote: Why? Since the AU is fixed to the metre, why not just use the metre and its prefixes? From: Eric L Shuman Sent: Thursday, 2014-06-26 15:31 To: U.S. Metric Association Cc: U.S. Metric Association Subject: [USMA:54054] Re: New supplement to the SI Brochure Thanks for bringing this to my (our) attention! I use the astronomical unit in outreach work that I do, so this is good to be aware of. On 26 June 2014 07:36, James <[email protected]> wrote: Dear Folks, The BIPM has issued a supplement to the SI Brochure. It alters the order of the base units in defining derived units (Tables 6 and 7), it reflects the recent IAU decision to define the astronomical year as a fixed and exact number, and it makes some updates reflecting the latest CODATA, among other things. http://www.bipm.org/utils/common/pdf/si_supplement_2014.pdf Best regards, Jim Frysinger -- James R. Frysinger 632 Stoney Point Mountain Road Doyle TN 38559-3030 (C) 931.212.0267 (H) 931.657.3107 (F) 931.657.3108
