No. I find comparing in meters (with a suitable prefix) gives me a better sense of scale than mixing AU, light years, parsecs, and other obscure units with obscure inter-relationships. Determining that a light year is some 63000 AU is not particularly helpful.
As a general comparison, it is much easier to learn a few metric prefixes, usable with all units, to provide a short hand alternative to scientific notation for scale than to learn all the absurd interrelationships of Customary units. ________________________________ From: Paul Rittman <[email protected]> To: U.S. Metric Association <[email protected]> Sent: Sun, April 3, 2011 10:24:24 AM Subject: [USMA:50263] re: astronomical measurements Knowing that the radius of earth's orbit is about 150 Gm, the scale between solar and interstellar distances is clearer to me than the mix of measurement units now used. John, when you say that, do you mean that you prefer to use the term au, or that you simply tell them that the au is 150 Gm, and then go on to use the metric numbers/terms? I do agree, that using the au does seem to provide a bit of scale, that even the term “light-year” doesn’t have. “Light-year” is very good for giving one a definition that you don’t easily forget, but isn’t good for much else, in that it is (almost) impossible to visualize the amount of space that is actually traversed in a year by anything, to say nothing of a ray of light. Au at least allows you to compare the stellar distance to our own solar system.
