The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
~ Arthur C. Clarke
This reminds me of a Calvin & Hobbes cartoon, where Calvin asks his dad how the load limit is determined for a bridge they're crossing. They send heavier & heavier trucks over it till the bridge collapses, his dad explains. Then they weigh the truck & rebuild the bridge. (It is easy enough to find the actual cartoon.)