My understanding is that the extremities of the universe are expanding at a velocity relative to Earth which is approaching the speed of light.
_____ From: [email protected] [mailto:[email protected]] On Behalf Of Bill Potts Sent: 24 March 2009 15:15 To: U.S. Metric Association Subject: [USMA:44097] RE: 285 yottametres Pat: You seem to be throwing zeroes around with abandon. The current estimate for the age of the Universe is about 13.5 billion years. That's 13 500 000 000, which is less than one thousandth of the 15 000 000 000 000 (15 trillion) you cite (a figure with which only Scientologists are likely to agree). Also, it's not expanding at the speed of light (an impossibility, according to Einstein). However, rather than my looking up the rate of expansion (which is, in any case, an estimate that has changed over the years -- just ask your friendly neighborhood astrophysicist), I suggest you do that yourself and redo your calculation. I think you'll come up with something considerably smaller than 285 Ym. I think yottameters may be useful for speculation about how big the Universe might be when it approaches its ultimate cold and lifeless state. (Oh, entropy, where is thy sting?) That time is a yotta-oops, lotta-seconds away. Best regards, Bill _____ Bill Potts W <http://wfpconsulting.com/> FP Consulting Roseville, CA http://metric1.org <http://metric1.org/> [SI Navigator] Dear Bill, Thanks for your thoughts. Perhaps it will help if I place it into context for you. Let's say that I want to write these paragraphs: The 'Big bang' theory of the Universe is based on the observation that all the stars and galaxies in the Universe seem to be moving away from each other. If you calculate their speeds of separation, you can calculate that the Universe might have begun with a 'Big Bang' 15 000 000 000 000 years ago. As we observe the speeds using light, it follows that the diameter of the Universe is twice the distance that light can travel in 15 000 000 000 years or the diameter requires 30 000 000 000 years. As light travels nearly 9 500 000 000 000 kilometres in a year, this means that the Universe is approximately: 30 000 000 000 years multiplied by 9 500 000 000 000 kilometres per year which equals 285 000 000 000 000 000 000 000 kilometres This is a very large number and before the metric system was developed people, even scientists and mathematicians, had difficulty saying or writing such big numbers. These days we simply say that the diameter of the Universe is about 285 yottametres. The metric system has given us simple methods to handle very large numbers, very small numbers, and all of the numbers in between. _____ From: [email protected] [mailto:[email protected]] On Behalf Of Pat Naughtin Sent: Tuesday, March 24, 2009 02:01 To: U.S. Metric Association Subject: [USMA:44092] RE: 285 yottametres On 2009/03/24, at 7:37 PM, Bill Potts wrote: Grammatically, yes. Numerically, I don't know. Seriously, though, if someone has provided the diameter in either light years or parsecs, a conversion is simple arithmetic. You realize, of course, that you may be dealing with a hypersphere, in which case, wherever you are, you're always at the center (or hypercenter). If that's so, I'm not sure where the hypersurface of the hypersphere is. As a diameter is twice the distance from the center to the surface (or hypercenter to hypersurface), all I can do is quote Mr. Gumby (of Monty Python fame) and say that my brain hurts. :-( Bill _____ Bill Potts W <http://wfpconsulting.com/> FP Consulting Roseville, CA http://metric1.org <http://metric1.org/> [SI Navigator] From: [email protected] [mailto:[email protected]] On Behalf Of Pat Naughtin Sent: Monday, March 23, 2009 22:16 To: U.S. Metric Association Subject: [USMA:44089] 285 yottametres Dear All, I wonder if you would mind checking a calculation for me. I want to write: 'The Universe is approximately 285 yottametres in diameter.' Is this correct? Cheers, Pat Naughtin 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 <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.
