The pixel I believe is an artifact of the display screen. It is rectilinear on nearly all computer screens and is also square on most recent ones. Like the dot in a dot matrix printer, it corresponds to an electric charge and is dimensionless. An array of pixels can be electronically mapped onto an area of any shape.
I see less ambiguity in saying "square meters": I have heard some people say things like 3 square meters = 3 meters squared. In fact 3 meters squared = 9 square meters, as you know. Thanks. On 1/14/11 11:59 AM, "mech...@illinois.edu" <mech...@illinois.edu> wrote: > Michael, Jon, and Patrick, > > The "best" unit for TV screen area (size) is the coherent SI unit "meter > squared." > Flat screens of area about 1 m^2 and larger are already quite common. > > The "best" unit for TV pixel density is the unit "pixels per meter squared." > (I hesitate to call "pixels/m^2" an "SI unit." How is "pixel" related to SI? > > Of course, SI prefixes may be applied to the numerators of each unit > (preferably, excluding prefixes in the denominators). > > Gene. > > ---- Original message ---- >> Date: Fri, 14 Jan 2011 07:00:14 -0500 >> From: Jon Saxton <spam.t...@verizon.net> >> Subject: [USMA:49509] Re: Screen size conundrum >> To: "U.S. Metric Association" <usma@colostate.edu> >> >> I thought about this issue about 4 years ago. I think the best unit for >> measuring screen sizes is dm² but I expect an adverse reaction from >> other members of this list. >> >> >> On 2011-01-12 1858, Michael GLASS wrote: >>> Dear People, >>> >>> There's a real problem with electronic screen sizes - all of them. This >>> includes cameras, video cameras, computers, DVD players GPS monitors and >>> television sets. >>> >>> >>> 1 Because the screens are different shapes, there is no fixed relationship >>> between the size of the screen and the measure given. >>> >>> 2 Even in cases where there is a fixed ratio between shape of the screen and >>> the size of the screen, the increase in the size is not linear, but is >>> related to the square of the number given. >>> >>> 3 As a result, power consumption on larger screen sizes is far higher than >>> might be anticipated by looking at the screen size. For example, a 15 inch >>> computer monitor is very nearly a 33% larger than a 13 inch model whereas 15 >>> is just over 15% larger than 13. >>> >>> 4 With the issue of global warming, the power consumption of larger screens >>> is a matter of increasing concern. >>> >>> 5 Even if you express screen sizes in metric terms the diagonal is still a >>> misleading measure of the size of the screen. >>> >>> It seems to me that the best way to express the size of the screen is to >>> give its area. So here is my conundrum: would it be better to express this >>> size in square metres, square millimetres or square metres? What do others >>> think? >>> >>> Michael Glass >>> >>> >> >
