Inspired by a comment by Mico in a totally unrelated question, I want to know if someone of you know why font sizes are based on a linear progression of 1.2. The author of the comment suggest that probably it has to do with the fact that 1.2 ≈ ⁴√2̅ . Someone of you know why and, maybe, has some reference to it?
Note This question is on typography in general more than on LaTeX but I think that probably this is the best place to ask, otherwise feel free to migrate my question to a more proper place.
Edit Mico pointed out that the linear progression of 1.2 is only for larger font sizes of
\normalsize while for smaller font sizes the linear progression of 0.7 is used (0.7 ≠ 1/1.2 = 0.833). So the main question still remain and a new one arise: why for smaller font sizes of
\normalsize the linear progression of 0.7 is used and why it's different from the one used for larger font sizes of