Recent content by PMH

Well, fine. What would you say it should be represented by? (not that that's all that important) I was just trying to get at the fact that its form should signify that it's not a fraction - ie: one that can be either reduced or multipied by k/k without having its meaning changed.

Thank you. It turns out that what you - and nearly everyone else, I wager - perceived here, seeing these things that look like fractions, as fractions (ie: that may be reduced or represented as decimals) are in fact not. (IOW, they are assumed to be ... not reducible) A better representation...

from Skipjack at myMathForum.com: "I've come across it before, this article can serve as a reference for you, and this interesting article makes use of it." Terms ("keywords"): Mediant, Farey sequence

I ran across this years ago. It’s defined by the addition rule: a/b + c/d = (a+c)/(b+d) (Sounds crazy – until you think of x/y as meaning There’s a pile of x things on one side, and one of y things on the other.) Applying it in almost a Pascal's Triangle sort of way generates ... er, a...

Thank you, Andy. Now I'm sorry that I didn't make it clear that that's exactly what I have been doing - for many months. In fact, I'm pretty confident that I've figured out the answer; what I want is to check it via seeing how actually knowledgeable people in the field of X-Ray optics treat...

(My (old) background is math & computer science. I've long loved (mostly) precious opals - for their esthetics, lapidary potential, synthesis (which I've done), and how the play-of-color ("PoC") is produced.) I recently did another couple of passes on the latter in the process of trying to...

peterson1972, It's not clear what you're saying (that you heard) needs professional tools. I'm doing it w/ just: some glassware (flasks, beakers, pipettes) (optional) a magnetic stirrer (really do need something like this - although I've seen people make them from fish-tank...

TalonD, I have made synthetic opal(ine material - ie: not hardened) using a process similar to the one you give. I used TEOS, reagent-grade ammonia, reagent-grade alcohol (denatured, I think), and super clean water ("triple distilled" or some such). I have not tried it with ~store grade~...