Received: from mail-pb0-f61.google.com ([209.85.160.61]:32869)
	by stodi.digitalkingdom.org with esmtps (TLSv1:RC4-SHA:128)
	(Exim 4.76)
	(envelope-from <lojban+bncCMGclZyxExCpn5OBBRoEjWDRJg@googlegroups.com>)
	id 1SzlDL-000400-PS; Fri, 10 Aug 2012 02:09:07 -0700
Received: by pbbrp2 with SMTP id rp2sf1528108pbb.16
        for <multiple recipients>; Fri, 10 Aug 2012 02:08:58 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=googlegroups.com; s=beta;
        h=x-beenthere:received-spf:mime-version:in-reply-to:references:date
         :message-id:subject:from:to:x-original-sender
         :x-original-authentication-results:reply-to:precedence:mailing-list
         :list-id:x-google-group-id:list-post:list-help:list-archive:sender
         :list-subscribe:list-unsubscribe:content-type;
        bh=sjDXqO294cV/WeP8sZ9Wkc7Z8Pr1cX+hkyLgZLOBofE=;
        b=h0FeltRFiC+uvKAq6P8zXVDzHyN4c4d8r+3ImLqvNVL9wrvRksNtIbNNqgTX9J5BLx
         d375AveYKkmEnef8Kkb1DHprsEv1IoRq1M3Obq4nsqIQv+7gNpk67YNfOI1ZpocIEpCw
         f6kg5D3I7XYeVnDhwcRqIuYzw0HbV2z3JVXSI=
Received: by 10.236.182.35 with SMTP id n23mr471878yhm.5.1344589737497;
        Fri, 10 Aug 2012 02:08:57 -0700 (PDT)
X-BeenThere: lojban@googlegroups.com
Received: by 10.236.120.244 with SMTP id p80ls6920564yhh.0.gmail; Fri, 10 Aug
 2012 02:08:57 -0700 (PDT)
Received: by 10.101.7.16 with SMTP id k16mr328477ani.4.1344589737028;
        Fri, 10 Aug 2012 02:08:57 -0700 (PDT)
Received: by 10.101.7.16 with SMTP id k16mr328476ani.4.1344589737012;
        Fri, 10 Aug 2012 02:08:57 -0700 (PDT)
Received: from mail-gh0-f182.google.com (mail-gh0-f182.google.com [209.85.160.182])
        by gmr-mx.google.com with ESMTPS id r20si337270ano.1.2012.08.10.02.08.56
        (version=TLSv1/SSLv3 cipher=OTHER);
        Fri, 10 Aug 2012 02:08:57 -0700 (PDT)
Received-SPF: pass (google.com: domain of escaaape@gmail.com designates 209.85.160.182 as permitted sender) client-ip=209.85.160.182;
Received: by mail-gh0-f182.google.com with SMTP id r13so1613786ghr.13
        for <lojban@googlegroups.com>; Fri, 10 Aug 2012 02:08:56 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.50.41.233 with SMTP id i9mr1112310igl.41.1344589736767; Fri,
 10 Aug 2012 02:08:56 -0700 (PDT)
Received: by 10.64.124.37 with HTTP; Fri, 10 Aug 2012 02:08:56 -0700 (PDT)
In-Reply-To: <CAMKwHj1QD5BoFVLpJh4rCT=DWzU5vy0thCnxg2iPKZ8+Zx0KFA@mail.gmail.com>
References: <e4a06349-05ee-4a2c-b1ca-31463945eec6@googlegroups.com>
	<CAMKwHj0sAbPpqmdapxk3F0bdB5r0F-nojb3g_oCfXdNoJgjX8g@mail.gmail.com>
	<CAMKwHj27ftNYbKhPaAWmNTa-tP9rRFwHGEyz0930z9_R7CJEeA@mail.gmail.com>
	<201aced6-3e11-408d-b3ec-c31d042519c7@googlegroups.com>
	<50eeeab2-c661-4c30-8cda-2f9ddb8767de@googlegroups.com>
	<CAMKwHj2SAxDE+xm9xQrPE=1rVVaA=e3gDpVRYKj42CbRWMnLZg@mail.gmail.com>
	<d78c3727-c352-4636-b88a-7a25421cde84@googlegroups.com>
	<CAMKwHj00vMUsNxYnrai2744ngpfmuMi=NQ8hiyBK2em7Psn2rg@mail.gmail.com>
	<c9db7bda-ed4f-4503-9883-0afa6832d4d5@googlegroups.com>
	<CAMKwHj0WruvWG2G-xJ17-tbL=1xdRwGge4RaWcvnuaOcDFuOpA@mail.gmail.com>
	<4bdee803-3d24-474b-bf12-ced2d730960a@googlegroups.com>
	<CAMKwHj3riRexH5unc6oLs3FaTCxts7gxTL9cUs8R+phHDnqybQ@mail.gmail.com>
	<CAMKwHj1MyXCG_8n5xcTr_1k4BH4A7SWyWZwquQO8AG0so9Z4-A@mail.gmail.com>
	<CAMKwHj1QD5BoFVLpJh4rCT=DWzU5vy0thCnxg2iPKZ8+Zx0KFA@mail.gmail.com>
Date: Fri, 10 Aug 2012 11:08:56 +0200
Message-ID: <CAGO2uOOofAU=i60Zry7UMdcj+o7Ft7mGMm-w1xVdb7qnLNxQTQ@mail.gmail.com>
Subject: Re: [lojban] Direction of Rotation
From: Escape Landsome <escaaape@gmail.com>
To: lojban@googlegroups.com
X-Original-Sender: escaaape@gmail.com
X-Original-Authentication-Results: gmr-mx.google.com; spf=pass (google.com:
 domain of escaaape@gmail.com designates 209.85.160.182 as permitted sender)
 smtp.mail=escaaape@gmail.com; dkim=pass header.i=@gmail.com
Reply-To: lojban@googlegroups.com
Precedence: list
Mailing-list: list lojban@googlegroups.com; contact lojban+owners@googlegroups.com
List-ID: <lojban.googlegroups.com>
X-Google-Group-Id: 1004133512417
List-Post: <http://groups.google.com/group/lojban/post?hl=en_US>, <mailto:lojban@googlegroups.com>
List-Help: <http://groups.google.com/support/?hl=en_US>, <mailto:lojban+help@googlegroups.com>
List-Archive: <http://groups.google.com/group/lojban?hl=en_US>
Sender: lojban@googlegroups.com
List-Subscribe: <http://groups.google.com/group/lojban/subscribe?hl=en_US>, <mailto:lojban+subscribe@googlegroups.com>
List-Unsubscribe: <http://groups.google.com/group/lojban/subscribe?hl=en_US>, <mailto:googlegroups-manage+1004133512417+unsubscribe@googlegroups.com>
Content-Type: text/plain; charset=ISO-8859-1
X-Spam-Score: -0.7 (/)
X-Spam_score: -0.7
X-Spam_score_int: -6
X-Spam_bar: /

.

No matter however precise one is, one cannot define the direction of
rotation of a spinning object without giving an arbitrary (or a
"cultural") reference frame.  (Viz, the sun, a clock, some move with
his right hand, and so on).

The reason for this is geometrical and nearly metaphysical : it is a
well-known problem of epistemology, which was first noted by Kant in
his Critique of Pure Reason (in Transcendental Aesthetics), then also
noted by Lewis Carroll and Wittgenstein.

There's nothing in the pure 3d-euclidian geometry that can induce
something such as a "clockwise" or "counter-colckwise" movement, since
there is no arbitrary preference to stipulate the x, y and z-vectors.

Thus, the only thing you can say is that some determinante has value
+1 or -1, and that some rotations share the same value (though you
cannot say which one without arbitrary), and others share opposite
values.

This is such set that, were we bound to communicate with an alien race
in a parallel universe which we could not visit, but only speak about
it, we would have no clue whether some movement would be clockwise or
counterclockwise, and indeed, it is even the case that it would make
no sense at all.

Thus, the only convincing way to define the direction of rotation is
to culturally bind it to some famous move, e.g. the move of the hands
of some clock, for instance.

-- 
You received this message because you are subscribed to the Google Groups "lojban" group.
To post to this group, send email to lojban@googlegroups.com.
To unsubscribe from this group, send email to lojban+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/lojban?hl=en.