Does standardization count as an invention? Then I'd put the metric system higher than shipping containers. I'm not sure "you can pretty much build it yoursel

Does standardization count as an invention? Then I'd put the metric system higher than shipping containers. I'm not sure "you can pretty much build it yourself", either. The actual process is pretty involved [1]. Even if each step is simple, it's a lot of work, and building a large 3D object to precise specifications is not easy. [1]: https://www.youtube.com/watch?v=z7l6AQN1KV0 https://www.youtube.com/watch?v=z7l6AQN1KV0 On that note, though, I submit arc welding as a simple modern invention of great importance. Living in a city, it's rare that I'm not within 2 steps of some object that was joined with arc welding. The basic structure of an arc welder is really simple: an electric current, a wire feeder, and some way (like a noble gas) to protect it.