From owner-freebsd-stable@FreeBSD.ORG Tue Nov 23 16:47:26 2004 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 54A0A16A4CE for ; Tue, 23 Nov 2004 16:47:26 +0000 (GMT) Received: from sccrmhc11.comcast.net (sccrmhc11.comcast.net [204.127.202.55]) by mx1.FreeBSD.org (Postfix) with ESMTP id E375243D39 for ; Tue, 23 Nov 2004 16:47:25 +0000 (GMT) (envelope-from rob@pythonemproject.com) Received: from [127.0.0.1] (c-67-169-203-186.client.comcast.net[67.169.203.186]) by comcast.net (sccrmhc11) with ESMTP id <2004112316472401100ojghle>; Tue, 23 Nov 2004 16:47:25 +0000 Message-ID: <41A36A2B.8030403@pythonemproject.com> Date: Tue, 23 Nov 2004 08:49:47 -0800 From: Rob User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20040910 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "M. Warner Losh" References: <20041116172445.GA14385@kayjay.xs4all.nl> <419A6ED9.9030301@pythonemproject.com> <41A1684E.1020302@itga.com.au> <20041122.173024.69158626.imp@bsdimp.com> In-Reply-To: <20041122.173024.69158626.imp@bsdimp.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit cc: gnb@itga.com.au cc: freebsd-stable@freebsd.org Subject: Re: What OS are you? fun X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: rob@pythonemproject.com List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Nov 2004 16:47:26 -0000 M. Warner Losh wrote: >In message: <41A1684E.1020302@itga.com.au> > Gregory Bond writes: >: Rob wrote: >: >: >>> You'd better cite your source and / or reasoning, as ~3*10^8m/s =is= >: >>> the >: >>> accepted constant speed of light in vacuum. >: >> >: It's deeper than that. The "second" and the "meter" are both defined in >: terms of wavelengths of light, which (as a consequence) fixes the speed >: of light _by definition_, at _exactly_ *299 792 458 m s^-1. > >The second is not defined in terms of the speed of light. It is >defined in terms of the number of hyperfine transitions of cesium: > >http://www.bipm.fr/en/si/si_brochure/chapter2/2-1/second.html > The second is the duration of 9 192 631 770 periods of the > radiation corresponding to the transition between the two > hyperfine levels of the ground state of the caesium 133 atom. > This definition refers to a caesium atom at rest at a > temperature of 0 K. > >The meter used to be defined in terms the wavelength of Krypton-86 >radiation, but that was changed in 1983. It is nowdefined in terms of >how far light travels in a given time interval. See >http://physics.nist.gov/cuu/Units/meter.html for a good historical >perspective. > >So the definition of the meter is dependent on the second, but the >second is independent. > >However, the definition implicitly assumes that today's fundamental >constants of the universe are indeed constant. There's been some >evidence that suggests, but is so far inconclusive, that some or all >of the fundamental constants of the universe may vary on the order of >a few parts in 10^15 over the last few billion years or so. The >definition of the meter was changed before this evidence was known. > >And this is indeed, very off topic. > >Warner > > > > Like I said before, go to www.nist.gov and read for yourself about all of this topic. Lets close it on that note LOL. Rob.