Eric Despite it shrinking down to a more dinky size in recent years, carrying an inhaler is still a real chore. Is it possible to store compressed gas in a more pocket friendly way or has it got to be cylindrical?

🏒 Lucian Marin You can always redesign the enclosure of a cylindrical inhaler to match the design of a pocket friendly Lytro camera. But I guess pharma companies don't have any interest in hiring the best industrial designers.

Nkrs Gas particles in the middle of the cylinder are surrounded by other particles evenly, so the total force and interaction is essentially cancelled out. On the other hand, particles that are on the edge, that is, next to the wall of the cylinder, only have neighbouring particles on one side, so interactions between these particles result in non-zero force. Thermodynamics tells us that systems in equilibrium gravitate towards the minimum amount of potential energy, which is best satisfied with a rounded shape where distribution of the extra energy on the surface is even. This is how surface tension works: water drops are spheres.

Mark Dain I think so else I'd expect to see more box shapes for storing gas (maximizes the available space). Perhaps someone better than physics can explain but my theory would be the shape allows you to store gas at very high pressures without breaking the container. Boxes are weaker due to the edges they have, whereas a cylinder doesn't really have an edge. Like with aerosols I think the pressure has to be higher in the can so spraying works properly. Which is maybe why nobody stores gas in a box; higher pressure makes up for the lost space stacking cylinders.