Comment by dotancohen

7 hours ago

Over long distances the string will sag in the middle. That's one of the reasons (not the only reason) construction uses lasers today.

5 comments

dotancohen

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boothby  4 hours ago

It depends what you need that line for -- if you're projecting onto a wall, that sag matters. If you're projecting onto the ground, it doesn't.

gacgacgac  5 hours ago

Folded paper won't?

  • boothby  3 hours ago

    If anybody has ever tried folding a very large paper (or, bedsheets, tarps, etc), they'll realize the wisdom of this comment. Our intuition from folding paper on the order of several to tens of centimetres does not scale to arbitrary size and precision. Paper is relatively rigid, but its rigidity is finite and ensuring local-to-global flatness becomes a painstaking endeavour.

    • srean  3 hours ago

      Then there is the puzzle of coming up with folds to intentionally increase the rigidity of the surface. Essentially, using Theorema Pizzarium