This is very interesting- I just wish I could add something to the subject. Maybe I'll go pick up some tubes/rods from the hardware store this weekend.
I understand the fact that a solid rod is stronger than a hollow rod given the same diameter. My question is whether this fact takes into account the weight of the rod itself.
Imagine two 20 foot long 1/2" diameter steel rods- one is solid and the other is hollow. Support these two rods at...