system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are bridges tested for how much weight they can hold without breaking the bridge?
gpt
It's not like they build the bridge and THEN test it for strength. The architecture of the bridge was designed under the principles of engineering in such a manner that the mathematics and physics behind the design equate to a certain amount of load capacity, above and beyond what the structure will ever be expected to hold during its life. By the time it is actually built the engineers know very well what the limits of the design are.