Some measures in pt, some in cm?

Question

Hi all,
to achieve most accurate layout in my pages documents, I would like to use the metric system for all measures, from font size to page size, and everything else.
Unfortunately, Pages seems to be quite picky about which units it accepts in the various measure entry fields. It doesn't seem to be possible to enter "0.5 cm" in a font size entry field, for example.
Why is this? Technically, I think it should be pretty straightforward to implement the functionality allowing the user to enter measures in whatever unit they like...
Is there a way around this?

Answer 1

To go back to source :
From Wikipedia
*Traditional American point system*
By the (Kasson) Metric Act of 1866 (Public Law 39-183), the US (survey) foot is 1200⁄3937 m. This is 0.0002% more than 304.8 mm, which is the length of the Anglo-Saxon compromise foot of 1959, used below. A typographic foot contains 72 picas or 864 points.
Nelson C. Hawks, in 1879, used a printer’s foot of an Anglo-Saxon foot decreased by 0.375%. Therefore, the traditional ratio 7200⁄7227 (which reduces to 800⁄803) places Hawks’ point at 0.013 837 inch, or about 351.46 µm.
A second definition was proposed whereby there were exactly 996 printer’s points (= 83 picas) in 350 mm, which made the printer’s point about 0.013 848 867 inch ≈ 351.405 622 µm.
Finally, Lawrence Johnson stated in a third definition of printer’s foot that it should be 249⁄250 (99.6%) English foot. This means that the Johnson’s typographical point was 0.01383 inch, and was then converted by the 1959 value to 351.36 µm.
In 1886, the Fifteenth Meeting of the Type Founders Association of the United States approved the so-called Johnson pica be adopted as the official standard. *This makes the traditional American printer’s foot measure 11.952 inches* (303.6 mm), or 303.5808 mm exactly, *giving a point size of approximately 1⁄72.27 of an inch,* or 351.5 µm.
This is the size of the point in the TeX computer typesetting system by Donald Knuth, which predates PostScript slightly. Thus the latter unit is commonly called the TeX point.
Like the French Didot point, the traditional American printer’s point was replaced in the 1980s by the current computer-based DTP point system.
The printers had agreed to the standard earlier than I remembered, but it did take till after the turn of the century before this became the norm. There was a lot of legacy type such as woodblock and individual cast letters which would not have changed.
The invention of the Linotype hot metal system was about concurrent with the 1886 decision and may have forced it, as it required greater alignment in the forms. That I can't verify as it precedes even me, although I can remember the smell and sound of the Linotype when it was demonstrated to me in the back of an old local printers shop.
Peter