Whenever i see 27 i see 72 and i use the method of the cross (by way of summation and multiplication) on a septenary system. >>the rainbow ray for red light makes an angle of 42 degrees between the direction of the incident sunlight and the line of sight. Therefore, as long as the raindrop is viewed along a line of sight that makes this angle with the direction of incident light, we will see a brightening. The rainbow is thus a circle of angular radius 42 degrees, centered on the antisolar point, as shown schematically * https://files.catbox.moe/d51k7e.gif * https://files.catbox.moe/vnluc2.PNG Septenary cipher. RAINBOW 5+1+5+1+2+2+4= 20 RAIN 5+1+5+1=12 BOW 2+2+4=8 ------------------------- the circled square, A perimeter of 8 with a circumference of 9. NINE 1+5+1+5 = 12 EIGHT 5+5+7+6+7=30 12+30=42, here is the 42 1+2=3 ; 3+0=3 3+3=6, or 3 cubed 27. Here is the 27 ---------------- Thats all i could come up for the moment, what do you have in mind? EDIT: Try to make a rainbow indoors with no window. You wont be able to without a mirror.