By his definition, if he were inverted, his height could be taken as negative. However, I would argue human height is an unsigned scalar, much like speed vs. velocity.
--- On Sat, 7/11/09, Pat Naughtin <[email protected]> wrote: From: Pat Naughtin <[email protected]> Subject: [USMA:45345] Re: Vacuum display To: "U.S. Metric Association" <[email protected]> Date: Saturday, July 11, 2009, 11:27 PM On 2009/07/12, at 11:35 AM, Bill Hooper wrote: Bill Hooper 1810 mm tall, which means ... see below: (When standing, my head is 1810 mm high relative to my feet, which I consider the reference point or the "zero point".) Fernandina Beach, Florida, USA Dear Bill, I assume from this that human height must always be positive and that there is never an example of negative human height! ;-) Cheers, Pat Naughtin Author of the forthcoming book, Metrication Leaders Guide. PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com for more metrication information, contact Pat at [email protected] or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter to subscribe.
