Re: User Agents Do Not Implement Absolute Length Units, Places Responsive Design in Jeopardy

Applications are typically intentionally created for certain classes of
device; their developers just need a way to differentiate between these
devices reliably.

You wouldn't create a mobile application to have it turn up unexpectedly on
the wall of an airport.  However, if you were creating an application that
you intended to be run on mobile and on a kiosk, you want physical units +
Media Queries to tell you which one you're currently running on.

If the above two devices have the same resolution, or if the mobile & kiosk
vendor report the same subtended dimensions, you have no way to reliably
alter your layout.  That is a realistic use case for factual physical


On Wed, Oct 26, 2011 at 1:22 PM, Brad Kemper <> wrote:

> On Oct 26, 2011, at 10:04 AM, Boris Zbarsky wrote:
> > On 10/26/11 12:47 PM, Brian Blakely wrote:
> >> David, this is exactly why factual physical units are really, really
> >> important and useful.  A screen that will be viewed at TV-distance is
> >> likely a large display (e.g. a TV).
> >
> > Yes, but the converse is not true.  A large display per se tells you
> absolutely nothing about distance.  Maybe it's a TV to be viewed from 18
> feet, and maybe it's a wall-mounted touchscreen for a game (these are
> starting to appear in airports).  You just don't know.
> Right. Another similar case is flat screen TVs being used as posters. I see
> these in department stores all the time (often turned vertically), and the
> viewing distance is often within arms reach or so.

Received on Wednesday, 26 October 2011 20:39:27 UTC