Date: Sat, 30 Jun 2012 00:11:42 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: EPA and Vanagon Emissions
In-Reply-To: <4fee5ff3.0284cd0a.70a6.ffff9f82@mx.google.com>
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Perhaps I should have said 'originally' which is the answer I was
looking for ....just as a trivia thing .
I'd say my word 'derive' alluges to 'originally.'
from Wikipedia :
Originally intended to be one ten-millionth of the distance from the
Earth's equator <http://en.wikipedia.org/wiki/Equator> to the North Pole
(at sea level), its definition has been periodically refined to reflect
growing knowledge of metrology <http://en.wikipedia.org/wiki/Metrology>.
Since 1983, it has been defined as "the length of the path travelled by
light in vacuum <http://en.wikipedia.org/wiki/Vacuum> during a time
interval of 1 ? 299,792,458
<http://en.wikipedia.org/wiki/Speed_of_light> of a second
<http://en.wikipedia.org/wiki/Second>".^[1]
<http://en.wikipedia.org/wiki/Meter#cite_note-Res1-0>
or .. it is 10 million meters from North Pole to equator at sea level,
and that was the origin of the linear measurement we know as the meter.
Which is 10,000 Km I think,
which is about 6,200 miles, which is about right.
To make it actually useful and precise they came up with platnum-iridium
bar and all that later.
OK ..
how come there is only one time system around the world ? Why is it all
seconds, minutes, and hours everywhere..
and doesn't some culture somewhere have another system for units of time ??
When was the concept of hours and minutes invented, and by whom ?
Wait until I say why things fall over . Or what feature makes something
tippy and something else stable .
That's too easy. People should be able to say what makes something tippy
or not, if they think about it.
And when you see that, you will realize that a wheel is actually
composed of a a point that is continuously falling .
Scott
On 6/29/2012 7:09 PM, David Beierl wrote:
> At 02:41 PM 6/29/2012, Scott Daniel - Turbovans wrote:
>> Where did they derive that dimension from ?
>
> As Mike said...but the actual definition from 1889 to 1960 was the
> distance between two scribed lines on a platinum-iridium bar kept at
> the International Bureau of Weights and Measures in France, measured
> at the melting point of ice. In 1960 it was redefined in terms of
> the wavelength of a particular emission line in the spectrum of
> krypton-86, and in 1983 redefined once again as the distance light
> travels in vacuum in a specific time (roughly one three hundred
> millionth of a second).
>
> Here's a photo of the working end of one of the original prototype
> metre bars, specifically the one that was the US National standard
> for the meter until 1960. http://museum.nist.gov/object.asp?ObjID=37
>
> Yours,
> David
>
