There is a category of object where the useful part is the absence rather than the substance, and netting is the clearest example.
A net is mostly nothing. The material…
There is a constraint on ships that has no equivalent on land and that determines almost everything about how vessels are shaped and sized.
The constraint is that a vessel…
There is a failure mode in any signalling system that is worth more attention than the system itself, and lighthouses have an obvious one.
A light works by being seen.…
There is a problem in measurement that comes up whenever something matters and cannot be instrumented reliably.
The problem is that a quantity may be important, variable and consequential while…
What makes a sea crossing different from every other way of covering the same distance is that you can see the distance being covered, and you are free to move…