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Re: [CSS21] 4.3.2 Lengths (reference pixel?)

From: Brad Kemper <brad.kemper@gmail.com>
Date: Sat, 11 Dec 2010 14:47:10 -0800
Message-Id: <60A90063-8391-4478-97E8-269AFB16B011@gmail.com>
Cc: "www-style@w3.org" <www-style@w3.org>
To: "Dr. Olaf Hoffmann" <Dr.O.Hoffmann@gmx.de>


On Dec 11, 2010, at 11:00 AM, "Dr. Olaf Hoffmann"
> 
> As already mentioned before instead of '1in is equal to 2.54cm.'
> it should be: 'note, that 1in is equal to 2.54cm.'
> And if the last line persists, there is no need anymore for
> 'The absolute units consist of the physical units (in, cm, mm, pt, pc) and the 
> px unit:', this can be shortened to:
> 'The absolute units consist of the physical units:'

> A physical unit like a centimeter is always related to a physical measurement
> of a length, not to viewing circumstances or resolutions of devices - this is
> the whole point about it, a centimeter is a device independent absolute
> unit and it is defined in such a way, that this entity is independent from the
> method used to realise/present it, else it is not a centimeter. 
> There is no choice. 

The point you seem to be missing is that we are not trying to define inches and centimeters. We are defining the CSS units of 'in' and 'cm'. In some contexts, these have a direct relationship to inches and centimeters, and in others they do not. On projector screens, for instance, 'in' is just about as divorced in meaning from a physical "inch" as it is from the preposition "in". 
Received on Saturday, 11 December 2010 22:47:50 GMT

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