How convenient then, that the bottom of window panes were made just wide enough for how thick they’d get.
4 feet of steel tubing will flex under it’s own weight, but it’s not going to keep flowing under its own weight over time.
It might make a good MythBusters experiment or, if someone has the desire to do it at home, measure the sag in a piece of thin-wall glass tubing after x number of months/years compared with the sag in a piece of steel tubing.
A length of some heavy and ductile material like lead would definitely inelastically deform under its own weight. And I bet you could achieve the same with steel, with the right material dimensions – though that might involve a pretty thin ribbon
Just for the sake of determining the answer to the OP’s question, don’t you think the dimensions of the steel tubing should be the same as the dimensions of the glass tubing?
If a thin glass tube keeps bending under its own weight, then how come light bulbs and the like (large CRTS can have 10 tons or more of pressure on them) don’t slowly implode; we have light bulbs over 1 century old that haven’t noticeably deformed (and operating all that time, so warmer than room temperature).
That said, as others have noted, many other materials, whether metal, plastic or wood, will bend under their weight if not supported, with the bending slowly increasing (at a decreasing rate) over time until some equilibrium occurs, and remain bent if left in position long enough.
We have much to learn from these ancient and wise cultures.
I see I’ll have to journey to my old uni and measure the bottoms of the windows on campus. Will probably set off a terrorist alert or something.