'Yes it's prime numbers!!!' Since when have 30, 50 and 70 been prime numbers? If you divide any number by all but one of it's factors you'll get a prime number.

You're right Wyo, some of them are very beautiful. I don't see anything wrong with wanting an explanation for them, and I think it's quite in order to lightly tease someone who gives a partial, incomplete or poorly interpreted explanation.

If Little Hawk had said that the diameters are in the relationship 3:5:7 it would have been different. But as this particular example is measured in feet, a terrestrial system of units, it is reasonably logical to assume it to be of terrestrial origin.

Bert.