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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Why is a sextant like it is?
From: Gary LaPook
Date: 2004 Nov 19, 02:04 -0800
From: Gary LaPook
Date: 2004 Nov 19, 02:04 -0800
But, since 100 grads equals a right angle, and there are 10,000,000 meters between the equator and the north pole (this is the original definition of the meter) then an intercept of one grad would equal a distance of 100 kilometers and one milligrad 100 meters. this would be useful if we switched our distance measurement to kilometers and speed to kilometers per hour. This is also the basis for the UTM grid, the northing coordinate is meters from the equator. Gary LaPook George Huxtable wrote: >Alex asked- Why do we still use this terrible Babylonian hexadecimal system >for measuring angles? > >I agree, that it's terrible. > >The French had a go at decimalising it at the time of the Revolution, but >they bodged it. > >They proposed that a right-angle would be 100 grads, therefore 400 grads >for a complete rotation. I think that was misguided. A complete turn brings >you back to the starting point again, so that should have been the natural >basis for the standard unit, the Turn, to be divided into 1000 milliTurns. > >There was also a Revolutionary proposal to decimalise time measurement in >terms of the Day, but it failed, presumably because it would have made >every clock and watch obsolete. If it had succeeded, then the mean Sun >would make a Turn in 1 Day, and a milliTurn in a milliDay. And wouldn't >navigational calculations have been a lot simpler? > >George. > >================================================================ >contact George Huxtable by email at george@huxtable.u-net.com, by phone at >01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy >Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. >================================================================ > > >