X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from alnrmhc11.comcast.net ([206.18.177.51] verified) by logan.com (CommuniGate Pro SMTP 5.1.2) with ESMTP id 1605283 for flyrotary@lancaironline.net; Sun, 26 Nov 2006 18:14:18 -0500 Received-SPF: none receiver=logan.com; client-ip=206.18.177.51; envelope-from=rlwhite@comcast.net Received: from quail.site (c-68-35-160-229.hsd1.nm.comcast.net[68.35.160.229]) by comcast.net (alnrmhc11) with SMTP id <20061126231336b1100sn16ae>; Sun, 26 Nov 2006 23:13:56 +0000 Date: Sun, 26 Nov 2006 16:14:24 -0700 From: Bob White To: "Rotary motors in aircraft" Subject: Re: metric system- OT Message-Id: <20061126161424.71a95f85.rlwhite@comcast.net> In-Reply-To: References: X-Mailer: Sylpheed version 2.2.10 (GTK+ 2.8.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Hi Thomas, I think some of your information is dated. The primary standards have long passed the metal rod stage. The now use the wavelenght of some natural frequency. I think it used to be Cesium, but this stuff is always evolving. If I go to http://www.onlineconversion.com/volume.htm, they tell me that 1 cc = 1 ml. so the units may have been adjusted slightly to get them to work out. Also the relationship between the units is more straightforward in metric. The choice for what to use for the length of the meter was more or less arbitrary. I read an interesting book a while back called "Measuring America" by Andro Linklater. Along with an explanation of how the country was surveyed, there is a lot of information about the development of measurement systems including metric and the events surrounding those developments. One of the things I was most surprised about was that Thomas Jefferson was a proponent of a decimal system that was less arbitrary than the French system. For example the unit of length was tied directly to the unit of time by specifying the length of a 1 second pendulum as the basic unit of length and 1 inch = 1/10 foot Weight: 1 oz = 1 cu in of rainwater and 10 ounces = 1 lb Volume: 1 bushel = 1 cu ft Thomas J. didn't get his decimal system implemented, but he did manage to get the currency decmalized so we have pennies and dimes instead of pence and shillings or pieces of eight or whatever. Bob W. On Sat, 25 Nov 2006 18:12:04 -0800 Steve Thomas wrote: > I don't get it. All measurement systems are arbitrary. The > "English" system certainly came from some odd roots. But so did the > railroad track gauge (it was the width of a horse drawn wagon > track.) And guess what else? The Space Shuttle booster rockets were > designed around the same gauge so it could be shipped to its final > destination. The metric system was designed around what they thought > was the circumference of the earth. They got it wrong. And, 1 cc is > not the same as 1 ml., though that was the intent. Now, all > measurements are based on a metal rod, or other device, residing in a > refrigerator at a constant temperature in the National Weights and > Measures office for the US and somewhere in France for metric > measurements. > > OK, the SAE system may be a little convoluted, but once you learn it, > it works just fine. Oh, I forgot, we should change just because the > Europeans use it. Should we also adopt soccer as our national > pastime just because the "rest of the world" sees soccer as their > national pastime? I mean, almost no one adopts our version of > football. Just because "they" do it is not an a-priori reason do to so. > > Will we eventually migrate over to metric de-facto even though we > have rejected a de-juris solution? Maybe. But in the interim, SAE > works just fine, and in the absence of a compelling economic reason > to do so, if it ain't broke, don't fix it. > > Best Regards, > > Steve > > ____________________________________________________________________ > > > On Nov 25, 2006, at 5:40 PM, Bulent Aliev wrote: > > >> I just think it is embarrassing that the US cant seem to adopt the > >> international system... > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com First Flight: 11/23/2006 7:50AM - 0.4 Hours Total Time Cables for your rotary installation - http://www.roblinphoto.com/shop/