hollow things

It strikes me that when you look at an object you can only see the surface, you can't see the inside at all (unless you cut or break it). This suggests to me that the inside is unnecessary, supurfluous, a waste of material and a cause of unnecessary waste.

There are things which nonetheless are hollow, such as bicycle frames, scaffolding tubes, and teapots. There are different reasons for the hollowness, the teapot being hollow is more for the functionality of containing substances which does not concern us here. The scaffolding tube and the bicycle frame are hollow because it saves on material and makes them lighter than if they were solid.

However, the walls of the tubes are solid! There must be some potential for saving weight and materials here!

I remember reading that aluminium tubes e.g. as used in bicycles could be made a lot thinner than they actually are, for strength, but they would then dent very easily and crumple. The example usually given is a beer can, which is very thin-walled, and plenty strong enough, but does not crumple because it contains pressurised liquid.

So, the logical conclusion is that every device ever designed created or used could be made in an optimal state with the minimum thin-ness of material forming its surface. However, these devices would be pretty much useless because they would crumple under their own weight.

So, make the surface sealed, add a pressure valve and a pressure gauge. Now all you have to do is grab a bicycle pump or air compressor (depending on the size of your device) and pressurise the air inside before using.

This technically doesn't count as being inflatable because the pressurised air doesn't actually inflate the device, it merely prevents denting and crushing.

You probably want to keep an eye on the pressure gauge and give it a few more puffs of air every now and again to keep the pressure within design tolerances.